The developmental architecture of the crop of quail embryos (Coturnix coturnix): Morphometric, light and scanning electron microscopy

The present study focused on the histogenesis of the crop in quail embryos. The developmental sequence was recorded from day 10 of incubation to the hatching day (17th day) by gross anatomy, morphometric analysis and by using light and scanning electron microscope (SEM). Grossly, the crop was distinguished as an enlarged pouch of the cervical oesophagus on the 12th day of incubation. Histologically, the development of the crop began on the 10th day of incubation. The muscularis mucosae was observed as a small, thin layer of myoblast cells on the 10th day, then it appeared as longitudinally arranged smooth muscle fibres with progression of the developmental age till hatching day. The submucosal layer was also observed on the 10th day, while the lamina propria, muscular layer (inner circular and outer longitudinal layers of smooth muscle fibre) and glandular primordia were detected on the 12th day. The epithelial cells of crop revealed affinity for PAS stain and AB-PAS on the 10th day of incubation till the 17th day, while the affinity for AB stain appeared on the 14th day of incubation. Additionally, the glandular cells showed the positive for AB, PAS and AB-PAS on the 12th day of incubation. SEM sections showed variable sizes of the openings of the oesophageal glands. In conclusion, the present study provided a detailed overview of the histogenesis of the crop in quail embryos.

Ocular and extraocular sebaceous carcinomas: A retrospective study with emphasis on the presence of in situ lesion and discussion and review of the histogenesis of extraocular sebaceous carcinoma

Sebaceous carcinoma (SC) is a rare carcinoma classified as ocular or extraocular. Ocular SC is believed to arise from the meibomian glands or the glands of Zeis. However, the origin of extraocular SC is controversial because there is no evidence of carcinoma arising from pre-existing sebaceous glands. Several hypotheses about the origin of extraocular SC have been proposed, including one suggesting an origin from intraepidermal neoplastic cells. Although extraocular SCs have been shown to occasionally comprise intraepidermal neoplastic cells, no study has investigated whether intraepidermal neoplastic cells possess sebaceous differentiation. The present study analyzed the clinicopathological features of ocular and extraocular SC, with an emphasis on the presence of in situ (intraepithelial) lesions. It retrospectively reviewed the clinicopathological features of eight patients with ocular and three patients with extraocular SC (eight women and three men; median age, 72 years), respectively. In situ (intraepithelial) lesions were observed in four of the eight ocular SC cases and one of the three extraocular SC cases and an apocrine component was noted in one patient with ocular SC (seboapocrine carcinoma). In addition, immunohistochemical analyses showed that the androgen receptor (AR) was expressed in all ocular SCs and two of the three extraocular SC cases. Adipophilin expression was observed in all ocular and extraocular SC. In situ lesions of extraocular SC showed positive immunoreactivity for both AR and adipophilin. The present study is the first to demonstrate sebaceous differentiation in in situ lesions of extraocular SC. The possible origin of extraocular SC is speculated to be the progenitor cells present in the sebaceous duct or interfollicular epidermis. The results of the present study and reported cases of SC in situ indicate that extraocular SC also arises from intraepidermal neoplastic cells.

Central Granular Cell Odontogenic Tumor: Review of Cases Reported in the Last 71 years and Report of a Case

Central granular cell odontogenic tumors (CGCOTs) are rare, benign, slowly growing odontogenic neoplasms. Due to their uncertain histogenesis, CGCOTs are still not included as a distinct entity in the WHO classification (2017) of odontogenic tumors. We report a case of CGCOT involving the right side of maxillary anterior region of a 39-year-old white female. Immunohistochemical staining showed granular cells positively expressed CD68 and vimentin, and negatively expressed S-100 protein. Meanwhile, we searched PubMed, Google Scholar, and Scopus databases to summary the clinico-pathological features of 51 published cases of CGCOT. The results showed the granular cells of 28.6% cases were immunopositive for vimentin and CD68, and odontogenic epithelial cells positive immunoreactivity for cytokeratin. These findings reinforced the mesenchymal origin of granular cells and the odontogenic nature of epithelium islands.

Isolation of a Population of Cells Co-Expressing Markers of Embryonic Stem Cells and Mesenchymal Stem Cells from the Rudimentary Uterine Horn of a Patient with Uterine Aplasia

More than 50% cells isolated from the endometrial cavity scraping and the myometrium of the rudimentary horn of an underdeveloped uterus removed from a patient with uterine aplasia and maintained under culturing conditions normal for mesenchymal stem cells (MSC) expressed embryonic transcription factors Oct4 and Nanog, embryonic cell membrane sialyl glycolipid SSEA4, and MSC markers. After 2-3 passages, the cells lost the expression of the early embryogenesis markers, but retained MSC markers. The presence of dormant stem cells in the underdeveloped endometrium and in the uterus indicates that this tissue has a regenerative potential that can be activated and used for completion of organ morphogenesis. This task requires the development of methods of early diagnosis of morphogenesis impairment and tools for safe reactivation of the ontogenesis.

Pancreatic Adenosquamous Carcinoma: A Rare Pathological Subtype of Pancreatic Cancer

Pancreatic adenosquamous carcinoma (PASC) is a rare pathological subtype of pancreatic cancer (PC), with a worse prognosis than pancreatic ductal adenocarcinoma (PDAC). Due to its rarity, our knowledge of PASC and its biological characteristics are limited. In this review, we provide an overview of the histogenesis, genetic features, diagnosis, treatment, and prognosis of PASC, as well as pancreatic squamous cell carcinoma (PSCC). The information provided here may help to clarify our understanding of PASC and provide useful avenues for further research on this disease.

A Comparative Morphometric and Histological Study of Human Fetus and Fetal Pancreas in Hyperglycemic and Normoglycemic Mothers

BACKGROUND

A significant percentage of pregnancies with gestational diabetes mellitus (GDM) has been found to result in the delivery of macrosomic babies. The current study intends to highlight the correlation between maternal diabetes and fetal parameters as well as the histogenesis of the fetal pancreas in humans.

MATERIALS AND METHODS

The study included thirty aborted fetuses, categorized into seven groups according to their gestational age. Morphometric analysis of fetal parameters and fetal pancreas was done, and the values were compared within different gestational age groups. Pancreatic tissue was processed, stained with Hematoxylin & Eosin, and examined. A comparison was then made between fetuses with and without gestational diabetes.  Results: All the fetal biometrics as well as pancreatic parameters showed greater numeric values in mothers with GDM as compared to the controls of the same gestational age groups. However, the difference was not statistically significant. Histogenesis in such fetuses revealed GDM-related hyperplasia of islets of Langerhans.

CONCLUSION

A timely diagnosis of GDM is thus of paramount significance due to its potential implications so that appropriate interventions can be done on time, to improve the overall outcome.

Molecular genetic evidence supporting diverse histogenic origins of germ cell tumors

Germ cell tumors (GCTs) originate during the histogenesis of primordial germ cells to mature gametes. Previous studies identified five histogenic mechanisms in ovarian mature teratomas (type I: failure of meiosis I; type II: failure of meiosis II; type III: duplication of the genome of a mature gamete; type IV: no meiosis; and type V: fusion of two different ova), but those of other GCTs remain elusive. In this study, we analyzed 84 GCTs of various pathologic types to identify the histogenesis using single-nucleotide polymorphism array by analyzing copy-neutral loss of heterozygosity (CN-LOH) and copy number alterations (CNAs). We detected types I and II in ovarian teratomas, type III in ovarian teratomas and yolk sac tumors (YSTs), and type IV in all GCT types. The GCTs with multiple-type histogenesis (I-IV) (ovarian mature/immature teratomas and YST) show meiotic CN-LOH with scant CNAs. Type IV-only GCTs are either with mitotic CN-LOH and abundant CNAs (seminoma, dysgerminoma, testicular mixed GCTs) or with scant CNAs and no CN-LOH (pediatric testicular and mediastinal teratomas). The development sequences of CN-LOH and CNA are different between the multiple type (I-IV) GCTs and type IV-only GCTs. We analyzed two different histologic areas in eight GCTs (one mature teratoma with a mucin-secreting adenoma, two immature teratomas, and five mixed GCTs). We found that GCTs (mature teratoma, immature teratoma, and mixed GCT) showed different genomic alterations between histologic areas, suggesting that genomic differences within a GCT could accompany histologic differentiation. Of note, we found evidence for collision tumors in a mixed GCT. Our data indicate that GCTs may have various histogenesis and intratumoral genomic differences, which might provide important information for the identification of GCTs, especially for those with different histologic areas. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Mesenteric and Retroperitoneal Mucinous Cystic Neoplasms: A Case Series

Aims. Mucinous cystic neoplasms (MCNs) are cystic neoplasms with mucinous epithelium surrounded by ovarian-like stroma. Extraovarian MCN occurring in the liver and pancreas have been well characterized. However, only rare case reports of MCN arising outside of these locations have been reported. MCNs arising in unusual locations should enter the differential diagnosis of mucinous intra-abdominal tumors and must be distinguished from more common mimics. Therefore, we aimed to examine a series of MCNs of the retroperitoneum and mesentery to characterize the clinicopathologic features of this entity. Methods and results. Seven MCNs arising in the abdominal mesentery or retroperitoneum were retrospectively identified. A clinicopathologic, histologic, and immunohistochemical (keratin 7, keratin 19, keratin 20, calretinin, inhibin-α, steroidogenic factor-1 (SF-1), estrogen receptor (ER), progesterone receptor (PR), PAX8, CDX2, and CD10) analysis was performed. All 7 MCNs were from females with a median age of 41 years old and a median size of 8 cm. All cases demonstrated mucinous with or without concomitant non-mucinous epithelium overlying spindle cell ovarian-like stroma. Luteinized cells were noted. The epithelium was positive for keratin 7 and keratin 19 in all 7 cases, while the stroma expressed ER, PR, and SF-1 in all cases stained. Calretinin was focally positive in the stroma of 3 of 7 cases, while inhibin-α was focally expressed in 5 of 6 cases. Conclusions. These results highlight the clinicopathologic, histologic, and immunophenotypic similarities between MCNs of the mesentery, retroperitoneum, pancreas, and liver. Overlapping features suggest a common histogenesis for all MCNs, which could include periductal fetal mesenchyme, aberrant migration of primordial germ cells, or abnormal differentiation or metaplasia of the embryonic coelomic epithelium.

Vascular tangle in the inter-atrial septum - Is it the source of cardiac myxoma?

Background

Cardiac myxomas (CMs) are the most common primary tumors of the heart, said to be derived from pluripotent cardiac stem cells. They are most often attached to the left side of the inter-atrial septum (IAS) and a feature noted at the site of attachment is a conglomeration of thick-walled vessels that has been noted to precede the development of myxomas.

Aims

The present study was conducted to compare histology of the normal inter-atrial septa to the septal flap excised with the myxomas and to evaluate the significance of this 'vascular tangle' in the histogenesis of these tumors.

Materials and Methods

In a 10-year retrospective analysis of all surgically excised CMs, tumors with attached septal sleeves were selected. This histology was compared to the serial sections of 25 normal age-matched septa obtained from normal hearts at autopsy.

Results

Of the 56 myxomas seen in 10 years, 38 tumors (all left atrial in location) were received with a flap of the IAS. All of these cases, irrespective of the sizes of the tumor, showed the presence of conglomeration of thick-walled blood vessels, many of which showed abrupt myxoid change in their walls. Another noteworthy feature in many vessels in all flaps was migration of the myxoid tissue through the vascular walls and the endocardium to mushroom out into the atrial lumen. Such vascular channels were not seen in any of the normal IAS.

Conclusions

Based on these findings, we propose a two-step hypothesis: an initial step that stimulates the pluripotent cells toward vasculogenesis with endothelial and smooth muscle differentiation, and a subsequent step leads to production of abundant mucopolysaccharides that splay apart the smooth muscle cells, which would explain rings, cords or nests of myxoma cells around endothelial lined spaces.

Histo-ontogenetic study of the parotid salivary gland of Indian buffalo

The present study was aimed at elucidating the histogenesis of parotid gland of buffalo. The study was carried out on buffalo foetuses (n = 36), during different stages of prenatal life. The foetuses were categorised into three groups based on their curved crown rump length (CVRL). The primordial anlage of parotid salivary gland was evident at 40th day of development whereas the primary ducts, in the form of cords, were first observed at 81st day of prenatal life. The capsule formation as well as the lobulation of the gland was initiated at 127th day. At 141st day, the duct system of gland was completed. The terminal tubules attained the structure of acini at 167th day. The myoepithelial cells first appeared as flattened basal cells initially around the developing acinar cells at 167th day. The typical compound tubulo-acinar nature of the gland was first observed at 185th day. Purely serous acinar cells were seen from 185th day onwards. The micrometrical studies revealed that the mean diameter of acinar cells, intercalated ducts, striated ducts and large ducts increased with the advancement of age. The serous acinar cells were devoid of acidic as well as neutral mucopolysaccharides in prenatal age groups; however, large ducts with goblet cells exhibited positive reaction. Combined PAS-AB method revealed mixed reaction in acinar cells as well as in large ducts. Fine lipid droplets were observed in intralobular as well as interlobular connective tissue; however, phospholipids were observed in the cell membrane of secretory cells and ducts.

Ciliated Muconodular Papillary Tumors of the Lung: Distinct Molecular Features of an Insidious Tumor

Introduction

Ciliated muconodular papillary tumors (CMPTs) are rare special peripheral pulmonary nodule composed of different cell proportions, characterized by papillary structures and significant alveolar mucus. Because of their rarity, underrecognized processes, the full range clinical course and histogenesis of CMPTs remains uncertain.

Methods

Molecular features of 5 CMPTs cases (one case with mucinous adenocarcinoma simultaneously) were observed by whole exon gene detection. The histological features of CMPTs and the development trends of three major constituent cells were studied by immunohistochemistry and PCR.

Results

NGS revealed 77 gene mutations in the patient's tumor tissue and 31 mutations in the border tissue. TMB of CMPT tends to TMB of cancer tissues, and both are higher than normal tissues, CMPT share the same phylogenetic tree with cancer tissues. Moreover, PDL1, B7H3, and B7H4 were overexpressed in high columnar cells and eosinophilic ciliated cells of CMPT, tends to cancer tissues, while LAG3 and siglec15 were not found in CMPT.

Conclusion

The high prevalence of driver gene mutations in CMPTs, similar TMB and phylogenetic tree with cancer tissues indicate their malignant potential. Distinct molecular and immune check point features of each component support the notion that ciliated columnar cells in CMPT are insidious with immune escape.

Merkel Cell Polyomavirus T Antigens Induce Merkel Cell-Like Differentiation in GLI1-Expressing Epithelial Cells

Merkel cell carcinoma (MCC) is an aggressive skin cancer frequently caused by the Merkel cell polyomavirus (MCPyV). It is still under discussion, in which cells viral integration and MCC development occurs. Recently, we demonstrated that a virus-positive MCC derived from a trichoblastoma, an epithelial neoplasia bearing Merkel cell (MC) differentiation potential. Accordingly, we hypothesized that MC progenitors may represent an origin of MCPyV-positive MCC. To sustain this hypothesis, phenotypic comparison of trichoblastomas and physiologic human MC progenitors was conducted revealing GLI family zinc finger 1 (GLI1), Keratin 17 (KRT 17), and SRY-box transcription factor 9 (SOX9) expressions in both subsets. Furthermore, GLI1 expression in keratinocytes induced transcription of the MC marker SOX2 supporting a role of GLI1 in human MC differentiation. To assess a possible contribution of the MCPyV T antigens (TA) to the development of an MC-like phenotype, human keratinocytes were transduced with TA. While this led only to induction of KRT8, an early MC marker, combined GLI1 and TA expression gave rise to a more advanced MC phenotype with SOX2, KRT8, and KRT20 expression. Finally, we demonstrated MCPyV-large T antigens’ capacity to inhibit the degradation of the MC master regulator Atonal bHLH transcription factor 1 (ATOH1). In conclusion, our report suggests that MCPyV TA contribute to the acquisition of an MC-like phenotype in epithelial cells.

Immunohistochemical characterization of postnatal changes in cerebellar cortical cytoarchitectures in ferrets

We immunohistochemically characterized postnatal changes in cerebellar cortical cytoarchitectures in ferrets using markers for cerebellar cortical neurons and glial cells. Although 10 lobules of the vermis were already observed on postnatal day (PD) 4, Purkinje cells were still arrayed into two to three layers. Purkinje cells were aligned in a monolayer by PD 10 and formed mature shapes on PD 42 by developing their dendritic arbors. Parvalbumin immunostaining revealed relatively slower maturation of Purkinje cells in the Lobule X cortex than in other lobules. Basket and stellate cells emerged in the molecular layer on PDs 21 and 42, respectively. Rosette-like arranged glutamate decarboxylase 65 and 67-positive puncta were observed in the inner granular layer (IGL) on PD 21. Proliferating cell nuclear antigen immunostaining appeared in the outer zone of the external granular layer (EGL) containing progenitors of granular neurons on PDs 4-21. Bergmann glial processes extending vertically through the molecular layer and EGL were visible with GFAP immunostaining on PD 10 and thereafter. Their somata, aligned in the Purkinje cell layer, showed immunopositivity to Sox2 already on PD 4 and subsequently to S100 protein on PD 10. Sox2-positive cells were found sparsely in the IGL. Few of them were NeuN positive on PD 90, predicting the possibility of adult neurogenesis. These immunohistochemical results revealed that ferrets underwent cerebellar cortical histogenesis during their postnatal life in sequences. Relatively slow development or maturation of the ferret cerebellum was revealed by the timing of the monolayer alignment and morphological maturation of Purkinje cells.

Blastic plasmacytoid dendritic cell neoplasm with a history of cytopenia: A case report

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare and aggressive hematologic malignancy arising from plasmacytoid dendritic cell precursors. The disease typically manifests in the skin, but it also evolves into a leukemic phase or can be complicated by other myeloid malignancies, especially myelomonocytic tumors. The association between these neoplasms is not fully elucidated. We report a case of BPDCN with a history of cytopenia that was supposed to be chronic myelomonocytic leukemia. The patient received intensive chemotherapy and achieved complete remission, but soon relapsed. The successive occurrence of myelomonocytic neoplasm and BPDCN is in accordance with the fact that they evolve from a common cell origin with a multilineage potential for myelomonocytic and plasmacytoid dendritic cell differentiation. This case may shed further light on the mystery of biology and the histogenesis of BPDCN.

[Cytotrophoblastic invasion is the most important mechanism of placentation and pregnancy progression]

The paper presents new Russian and foreign materials on cytotrophoblastic invasion, the most important mechanism of interaction between the placenta, fetus, and mother during the progression of physiological pregnancy. The original classification of placental cell development has been published; the initial wave of invasion, the main and additional ways of its implementation in the second trimester, and the formation of cytotrophoblastic plugs in the spiral arteries, and the fate of multinucleated giant cells have been characterized. Additional sources of invasive cells in the second trimester are presented. A general concept of cytotrophoblastic invasion as a regulator and main mechanism of transition from the histotrophic to more effective hemochorial type of fetal nutrition has been made. The modern definition of an invasive process is given. This information is important for obstetricians and pathologists who analyze the causes of obstetric complications.

Adenosquamous carcinoma development as a recurrence of squamous cell carcinoma in the oral floor: A case report

RATIONALE

Oral adenosquamous carcinoma (ASC) is rare and its origins are controversial. We here present a patient with oral ASC that developed after surgery for oral squamous cell carcinoma (SCC).

PATIENT CONCERNS

A 70-year-old man with SCC on the oral floor underwent surgical resection. However, the enlarged ulcer presented on the oral floor 9 month after surgery.

DIAGNOSES

The biopsy of the ulcer revealed a SCC. Imaging examinations detected enhancement of a large lesion expanded to the tongue, but no evidence of regional lymph node or distant metastasis was shown. Based on these results, local recurrence of the cancer was diagnosed (cT4aN0M0).

INTERVENTIONS

The surgery for the recurrent tumor was performed.

OUTCOMES

The pathological examination of the surgical specimen indicated recurrent tumor was ASC. Thus, histopathological and immunohistochemical analyses of both the initial SCC and the subsequent ASC were performed in an attempt to explore the origin of the ASC. As the results, pathological review of both tumors suggested the subsequent ASC was developed from the tumor cells with adenoid phenotype in the initial SCC.

LESSONS

This report suggests that the oral ASC was origin from the oral SCC, which can contribute to new knowledge for pathogenesis of oral cancer.

Intraneural granular cell tumor: Histologic spectrum and histogenetic implication

Granular cell tumor (GCT), despite its putative neural origin, commonly occurs in extraneural sites; only six single case reports of intraneural GCT have been described. We report an unique case as the only one with motor dysfunction, the longest duration of symptoms, and largest tumor size with resultant muscle atrophy and fatty infiltration. Upon review of these cases, the striking feature of intraneural GCT lies in its histologic variety, ranging from benign GCT, through plexiform, hybrid GCT and perineurioma to malignant GCT, encompassing the full spectrum of extraneural GCT. As the immunophenotypes of schwannoma and GCT are not exactly identical, together with evidence from ultrastructural studies, the more reasonable and likely possibility is that GCT originates from undifferentiated mesenchymal cells acquiring partial schwannian differentiation. Such postulation by virtue of the widespread occurrence of mesenchymal cells in the soft tissue, better explains the topographic distribution of GCT in extraneural and intraneural location.

Morphological Characteristics of the Developing Cecum of Japanese Quail (Coturnix coturnix japonica)

The current investigation was carried out to record the final stages of the development of both middle and distal parts of quail ceca, Coturnix coturnix japonica to understand the role of ceca in digestion, immune system, and absorption. The cellular and subcellular structures, including epithelial cell height, microvillus surface area, the proportion of goblet cells, the thickness of muscle layer, and cecum diameter showed great variations during the development. An undeveloped smooth muscularis mucosa was observed for the first time on the ED5. Primordia of glands were observed on the ED7. On the ED15, the middle part exhibited two shapes of mucosal villi: tongue-shaped villi and U-shaped. The plicae and crypts of Lieberkühn were demonstrated on the hatching day. The lymphatic tissues appeared in the wall of both parts of the ceca at the 4 weeks of age. Scanning electron microscopy revealed a great difference in the mucosal surface between different regions. Telocytes were observed in-between the muscle fibers and formed a network during the post-hatching period. Because of fermentation and other bacterial or chemical processes that have been shown to occur in the ceca, this study supports two hypotheses: the cecal development is related to diet and the cecal epithelium act as a site for primary absorption of nutrients or for re-absorption of electrolytes or amino acids derived from the urine.

Histogenesis of Merkel Cell Carcinoma: A Comprehensive Review

Merkel cell carcinoma (MCC) is a primary neuroendocrine carcinoma of the skin. This neoplasia features aggressive behavior, resulting in a 5-year overall survival rate of 40%. In 2008, Feng et al. identified Merkel cell polyomavirus (MCPyV) integration into the host genome as the main event leading to MCC oncogenesis. However, despite identification of this crucial viral oncogenic trigger, the nature of the cell in which MCC oncogenesis occurs is actually unknown. In fact, several hypotheses have been proposed. Despite the large similarity in phenotype features between MCC tumor cells and physiological Merkel cells (MCs), a specialized subpopulation of the epidermis acting as mechanoreceptor of the skin, several points argue against the hypothesis that MCC derives directly from MCs. Alternatively, MCPyV integration could occur in another cell type and induce acquisition of an MC-like phenotype. Accordingly, an epithelial as well as a fibroblastic or B-cell origin of MCC has been proposed mainly based on phenotype similarities shared by MCC and these potential ancestries. The aim of this present review is to provide a comprehensive review of the current knowledge of the histogenesis of MCC.

Expression of α-smooth muscle actin in benign and malignant salivary gland tumors: An immunohistochemical study

Background and Objectives

Myoepithelial cells (ME) are known to contribute in the patterning of salivary gland neoplasms (SGN) and possess cytoplasmic smooth muscle actin (SMA) revealed by alpha SMA (α-SMA). The present study aimed to assess the expression of α-SMA in selected benign and malignant SGN (pleomorphic adenoma [PA], mucoepidermoid carcinoma (MEC), adenoid cystic carcinoma (ACC), and polymorphous low-grade adenocarcinoma (PLGA).

Materials and Methods

The intensity and pattern of expression of α-SMA were studied in 25 cases of SGN's ACC (n = 7), MEC (n = 8), PA (n = 8), and PLGA (n = 2), and correlated with the histological patterns.

Results

Maximum expression of α-SMA in the epithelial compartment was seen in ACC, followed by PA, whereas MEC and PLGA showed completely negative staining. The connective tissue expression was mild in ACC and MEC. The myxoid stroma of PA with "melting" pattern was weakly positive for α-SMA. The stroma in PLGA showed complete negativity. In ACC, α-SMA-positive cells were lining the cribriform spaces, small islands, and dispersed within large islands. Small nests showed complete positivity for α-SMA.

Interpretation and Conclusion

In ACC, α-SMA expression supports the involvement of ME in epithelial organization explaining the histological patterns seen. In PA, the expression correlates with the predominantly secretory nature of ME. The absence of epithelial positivity in MEC and PLGA suggest that ME has less role to play in their histogenesis. The weak stromal positivity observed in MEC and ACC may be attributed to the positive immunoreactivity of myofibroblasts playing a role in modulating the course of SGN's.

Potential immmunohistochemical markers to characterize epithelial-mesenchymal transition in pleomorphic adenoma

BACKGOUND

The histogenesis process of pleomorphic adenoma (PA) of salivary gland continues to remain a controversial subject. In this neoplasm, transition occurs from an epithelial or myoepithelial cell to a stromal element and is called an epithelial-mesenchymal transition (EMT) resulting in heterogeneity. The present research was aimed to study the morphological characteristics of varied components and epithelial-mesenchymal transitions in PA using histopathological and immunohistochemical (IHC) analysis.

MATERIALS & METHODS

For this purpose 15 PAs cases were selected from the archives and from each case of PA and 5 cases of normal salivary gland, five additional sections were cut from each for immunohistochemical analysis using E- cadherin, vimentin and a-actin. The numbers of immunoreactive cells were semi- quantitatively measured and also determined the intensity of the immunostaining reaction.

RESULT

Immunohistochemically, as the cells transitioned from the lumial cells to descrete/detached cells of ductal structures, the percentage of positive cells tends to decrease for E- cadherin and increases for vimentin and actin. Additionally, neoplastic cells towards the periphery of ducal-cystic structures or completely detached cells in the stroma showed intense to moderate positivity for vimentin and alpha smooth muscle actin (a-SMA). Chondroid/ hyalinized or myxoid stroma showed variable staining with these markers.

CONCLUSION

Our study provides the evidence that epithelial-mesenchymal transition process represent the basic principle of the tisuse heterogeneity in pleomorphic adenomas.

Prenatal development of retina in buffalo (Bubalus bubalis)

The development of retina in Indian buffalo (Bubalus bubalis) has not been reported previously. The aim of the present study was therefore to report the major landmarks and the time course in the development of retina. Serial histological sections of Indian buffalo embryos and foetuses were used as group1 (<20.0 cm CVRL), group2 (>20.0 but <40.0 cm CVRL) and group3 (>40.0 cm CVRL). Age estimation was made on the basis of crown vertebral-rump length (CVRL), which ranged between 36 and 286 days (1.6-94.0 cm). The retina in Indian buffalo was developed in a similar manner to that of the other mammals with the principal differences in the time of occurrence of various layers of this nervous tunic. In 36 days (1.6 cm stage), the foetal retina was composed of pigmented layer and the layer of neuroblasts. Differentiation of layers was first observed in 47 days (4.0 cm CVRL) which became prominent in 52 days (5.1 cm stage). At 120 days (20.5 cm stage), the differentiation of inner plexiform layer and inner nuclear layer was evident. At 143 days (31.0 cm) foetal age, the faint line in neuroblastic layer was the first evidence of the future outer plexiform layer. In foetuses of group III, the retina was comprised of all 10 layers (eight cell layers and two membranes) viz. pigmented epithelium, layer of rods and cones, outer limiting membrane, outer nuclear layer, outer plexiform layer, inner nuclear layer, inner plexiform layer, ganglion cell layer, layer of nerve fibres and the inner limiting membrane.

Xanthomatous meningioma: A metaplastic or degenerative phenomenon?

Xanthomatous changes can be observed in various conditions including primary xanthomatosis that is linked to an underlying hypercholesterolemia and more commonly associated with secondary xanthomatous degenerative processes in neoplasm and chronic inflammation. Meningioma with extensive xanthomatous change is exceedingly rare. The presence of cholesterol clefts within this peculiar meningioma subtype has not been described. Herein, we report an unusual case of xanthomatous meningioma in an 83-year-old normolipidemic woman, who presented to us with worsening lower limb weakness and global aphasia. There was increasing evidence to suggest that the presence of xanthomatous changes in long-standing meningioma is merely a sequela of cellular degeneration rather than true metaplastic change as previously hypothesized. Hence, the diagnosis of "xanthomatous meningioma" in the metaplastic category should be revisited and considered as a distinct histological subtype. The possible histogenesis of such intriguing phenomenon is discussed with a review of the literature.

Adenosquamous carcinoma of the lung

Adenosquamous carcinoma of the lung (ASC), a relatively rare subtype of non-small-cell lung cancer, is defined as a malignancy containing components of lung adenocarcinoma (ADC) and lung squamous cell carcinoma (SCC). Although ASC has biological characteristics of ADC and SCC, it is not by any means a simple hybrid of two components above. It is extremely difficult to diagnose preoperatively; pathology of surgically resected gross specimen is the most effective means for adequate diagnosis of ASC. Platinum-based postoperative adjuvant chemotherapy for at least four cycles can significantly improve the survival in stage III patients with ASC. Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) such as erlotinib and gefitinib can be the effective therapeutic strategies for advanced EGFR-mutant ASC. The studies of crizotinib in the treatment of patients with ASC are very limited. Immune checkpoint blockade therapy may be a potential treatment choice for ASC patients.

[On the histogenesis of cardiac myxoma]

OBJECTIVE

to investigate the morphological and phenotypic features of cardiac myxoma (CM), to discuss argumentative issues on the sources of its growth.

SUBJECTS AND METHODS

The investigation included 176 sporadic and familial myxomas originating from different cardiac chambers (96% from the atria). The histological, ultrastructural, and immunohistochemical features of the cells and vessels of this tumor were studied.

RESULTS

The morphological and phenotypic features of the embryonic endothelium resembling the cells of the primary cardiovascular network were found in the cells and vessels of CM. No signs of other mesenchymal derivatives were detected.

DISCUSSION

The authors anticipate that there is focal cessation of maturation of the embryonic endocardial endothelium and its persistence - hamartia. Postnatal proliferation of embryonic hamartia forms the tumor hamartoma. Differentiated cells may retain the phenotypic (but not morphological) features of closely related cells that have a common precursor.

CONCLUSION

The results of the study have allowed the authors to consider CM to be hamartoma, a monohistioid benign embryonic endocardial endothelioma. Our findings do not exclude the possibility of developing CM from pluripotent mesenchymal cells.

Retinal histogenesis in an altricial avian species, the zebra finch (Taeniopygia guttata, Vieillot 1817)

Comparative developmental studies have shown that the retina of altricial fish and mammals is incompletely developed at birth, and that, during the first days of life, maturation proceeds rapidly. In contrast, precocial fish and mammals are born with fully differentiated retinas. Concerning birds, knowledge about retinal development is generally restricted to a single order of precocial birds, Galliformes, due to the fact that both the chicken and the Japanese quail are considered model systems. However, comparison of embryonic pre-hatchling retinal development between altricial and precocial birds has been poorly explored. The purpose of this study was to examine the morphogenesis and histogenesis of the retina in the altricial zebra finch (Taeniopygia guttata, Vieillot 1817) and compare the results with those from previous studies in the precocial chicken. Several maturational features (morphogenesis of the optic vesicle and optic cup, appearance of the first differentiated neurons, the period in which the non-apical cell divisions are observable, and the emergence of the plexiform layers) were found to occur at later stages in the zebra finch than in the chicken. At hatching, the retina of T. guttata showed the typical cytoarchitecture of the mature tissue, although features of immaturity were still observable, such as a ganglion cell layer containing many thick cells, very thin plexiform layers, and poorly developed photoreceptors. Moreover, abundant mitotic activity was detected in the entire retina, even in the regions where the layering was complete. The circumferential marginal zone was very prominent and showed abundant mitotic activity. The partially undifferentiated stage of maturation at hatching makes the T. guttata retina an appropriate model with which to study avian postnatal retinal neurogenesis.

Mixed adenoneuroendocrine carcinoma of the tongue arising within a congenital enteric cyst

BACKGROUND

Primary intestinal-type adenocarcinoma of the tongue is rare. This represents the first reported case of a primary mixed adenoneuroendocrine carcinoma (MANEC) of the tongue arising within a congenital enteric cyst.

METHODS

A 52-year-old man presented with a midline tongue mass that was connected to the mucosal surface with an epithelial-lined sinus tract. Morphological examination and immunohistochemical profiling of the neoplasm were performed.

RESULTS

Histopathological evaluation showed a primary MANEC arising within a preexisting congenital enteric cyst, comprising both adenocarcinoma and neuroendocrine components. The adenocarcinoma had a colonic-type morphology and coexpressed CK7, CK20, and CDX2. Imaging and colonoscopy excluded a distant primary colorectal neoplasm.

CONCLUSION

The association of primary MANEC of the tongue with a gastrointestinal heterotopic cyst supports an origin from entrapped endodermal elements as opposed to salivary duct origin. This case raises the awareness of a rare yet prognostically important complication of a gastrointestinal heterotopic cyst.

Embryology

With the growing recognition of the extent and prevalence of human cerebellar disorders, an understanding of developmental programs that build the mature cerebellum is necessary. In this chapter we present an overview of the basic epochs and key molecular regulators of the developmental programs of cerebellar development. These include early patterning of the cerebellar territory, the genesis of cerebellar cells from multiple spatially distinct germinal zones, and the extensive migration and coordinated cellular rearrangements that result in the formation of the exquisitely foliated and laminated mature cerebellum. This knowledge base is founded on extensive analysis of animal models, particularly mice, due in large part to the ease of genetic manipulation of this important model organism. Since cerebellar structure and function are largely conserved across species, mouse cerebellar development is highly relevant to humans and has led to important insights into the developmental pathogenesis of human cerebellar disorders. Human fetal cerebellar development remains largely undescribed; however, several human-specific developmental features are known which are relevant to human disease and underline the importance of ongoing human fetal research.

Endometrial stromal sarcoma in combination with mixed type endometrial carcinomas: A case report and literature review

RATIONALE

Endometrial stromal sarcoma (ESS) is rare, representing only approximately 0.2% of all uterine malignancies. Mixed type endometrial carcinomas (MT-ECs) are rare tumors with both type I and II features, and are difficult to diagnose. Cases of ESS and MT-ECs coexisting in the same patient are extremely rare. This study aimed to describe a case of ESS in combination with MT-ECs in a 47-year-old premenopausal woman.

PATIENT CONCERNS

A woman presented to the hospital complaining of occasional abdominal pain and had high tumor markers: cancer antigen (CA) 19-9 (263.6 U/mL) and CA 125 (428.0 U/mL). Transvaginal ultrasound examination revealed a complex mass (12.3 × 9.1 × 6.3 cm) with solid and cystic components on the right rear wall of the uterus. Abdominopelvic computed tomography images showed a pelvic cystic-solid mixed mass. The patient underwent an exploratory midline laparotomy. The mass was hypothesized to be malignant on the uterine posterior wall. Tumor deposits were found on bilateral parametrium. On peritoneal implantation, multiple metastases were seen on the serosal surface of the bowel and greater omentum. A frozen section revealed a spindle cell sarcoma.

DIAGNOSES

Pathological reports following surgery revealed concurrent ESS and MT-ECs.

INTERVENTIONS

The patient underwent a total abdominal hysterectomy, bilateral salpingo-oophorectomy, total omentectomy, and macroscopic clearance of the tumor. Adjuvant chemotherapy was given.

OUTCOMES

The patient was still alive when this report was written.

LESSONS

Considering the rarity of ESS in combination with MT-ECs, this study presented an overview of the literature and discussed a number of histological and clinical issues. Nevertheless, etiology and pathogenesis of these tumors need further investigation.

A case of mixed adenoneuroendocrine carcinoma of the pancreas: Immunohistochemical analysis for histogenesis

RATIONALE

Tumors with multiple histological features, such as adenocarcinomas and neuroendocrine carcinomas, were included as a new category of neuroendocrine carcinomas in the 2010 World Health Organization classification. We recently experienced a rare case of a pancreatic carcinoma with both adenocarcinoma and neuroendocrine carcinoma components, a so-called mixed adenoneuroendocrine carcinoma.

PATIENT CONCERNS AND DIAGNOSIS

A 66-year-old man was referred to our hospital with obstructive jaundice. Contrast-enhanced computed tomography images indicated a tumor located at the pancreatic head measuring 3.0 × 2.5 cm in diameter and invading the common bile duct. Cytological examination of the bile juice obtained by endoscopic retrograde cholangiopancreatography revealed adenocarcinoma cells. Pancreaticoduodenectomy was performed safely as radical resection.

INTERVENTIONS

Microscopically, the resected tumor consisted of tightly intermingled adenocarcinoma and neuroendocrine carcinoma components. On the immunohistochemical examination, p53 was ubiquitously positive in both components, whereas chromogranin A, synaptophysin and neuron-specific enolase, neuroendocrine markers, were limited to the neuroendocrine carcinoma component.

OUTCOMES

Thus, such features of both adenocarcinoma and neuroendocrine carcinoma observed microscopically and immunohistochemically seemed to indicate a composite tumor.

LESSONS

The findings of this case suggest that adenocarcinoma and neuroendocrine carcinoma may be derived from a single cancer stem cell.

Non-calcifying and Langerhans cell-rich variant of calcifying epithelial odontogenic tumor

This study reported the clinicopathological features, treatment and prognosis of nine cases of noncalcifying and Langerhans cell (LC)-rich calcifying epithelial odontogenic tumor (CEOT) collected from the English literature. Of the nine cases, seven were intraosseous and two were extraosseous. All nine tumors were found in Asian patients. The age of the nine patients ranged from 20 years to 58 years with a mean age of 41 years. There were five female and four male patients. The seven intraosseous cases included six in the anterior and premolar region of the maxilla and one in the posterior region and ascending ramus of the mandible. The two extraosseous cases were located at the upper lateral incisor and premolar gingivae, respectively. Of the seven intraosseous cases, five showed unilocular and two multilocular radiolucency without foci of calcification. Six of the seven intraosseous cases showed resorption of the tooth roots in the tumor-involved region. Histologically, noncalcifying and LC-rich CEOTs were composed of small nests and thin strands of tumor epithelial cells with a relatively high number of LCs among them. This was the reason why we classed these nine cases as noncalcifying and LC-rich CEOTs. Two extraosseous cases received total excision of the gingival mass. For the seven intraosseous cases, four accepted partial maxillectomy or mandibulectomy, two received total excision or enucleation, and one underwent curettage. The six cases with the follow-up information available showed no tumor recurrence after a follow-up period of 6 months to 10 years.

Chordoid Glioma of Third Ventricle With an Epidermoid Cyst: Coexistence or Common Histogenesis?

Chordoid glioma (CG) is a World Health Organization classified grade II tumor located exclusively in the region of anterior third ventricle. Association of CG with other lesions is extremely rare. We report a case of CG in a 45-year-old male coexisting with an epidermoid cyst in the third ventricle. Ultrastructural examination of the CG revealed microvilli, junctional complexes, and intermediate filaments within the cytoplasm suggesting origin from specialized ependyma. The association of the 2 lesions appears coincidental as convincing evidence for a common histogenesis was not found.

Morphogenetic and Histogenetic Roles of the Temporal-Spatial Organization of Cell Proliferation in the Vertebrate Corticogenesis as Revealed by Inter-specific Analyses of the Optic Tectum Cortex Development

The central nervous system areas displaying the highest structural and functional complexity correspond to the so called cortices, i.e., concentric alternating neuronal and fibrous layers. Corticogenesis, i.e., the development of the cortical organization, depends on the temporal-spatial organization of several developmental events: (a) the duration of the proliferative phase of the neuroepithelium, (b) the relative duration of symmetric (expansive) versus asymmetric (neuronogenic) sub phases, (c) the spatial organization of each kind of cell division, (e) the time of determination and cell cycle exit and (f) the time of onset of the post-mitotic neuronal migration and (g) the time of onset of the neuronal structural and functional differentiation. The first five events depend on molecular mechanisms that perform a fine tuning of the proliferative activity. Changes in any of them significantly influence the cortical size or volume (tangential expansion and radial thickness), morphology, architecture and also impact on neuritogenesis and synaptogenesis affecting the cortical wiring. This paper integrates information, obtained in several species, on the developmental roles of cell proliferation in the development of the optic tectum (OT) cortex, a multilayered associative area of the dorsal (alar) midbrain. The present review (1) compiles relevant information on the temporal and spatial organization of cell proliferation in different species (fish, amphibians, birds, and mammals), (2) revises the main molecular events involved in the isthmic organizer (IsO) determination and localization, (3) describes how the patterning installed by IsO is translated into spatially organized neural stem cell proliferation (i.e., by means of growth factors, receptors, transcription factors, signaling pathways, etc.) and (4) describes the morpho- and histogenetic effect of a spatially organized cell proliferation in the above mentioned species. A brief section on the OT evolution is also included. This section considers how the differential operation of cell proliferation could explain differences among species.

Statistical analyses in trials for the comprehensive understanding of organogenesis and histogenesis in humans and mice

Statistical analyses based on the quantitative data from real multicellular organisms are useful as inductive-type studies to analyse complex morphogenetic events in addition to deductive-type analyses using mathematical models. Here, we introduce several of our trials for the statistical analysis of organogenesis and histogenesis of human and mouse embryos and foetuses. Multidimensional scaling has been applied to prove the existence and examine the mode of interkinetic nuclear migration, a regulatory mechanism of stem cell proliferation/differentiation in epithelial tubular tissues. Several statistical methods were used on morphometric data from human foetuses to establish the multidimensional standard growth curve and to describe the relation among the developing organs and body parts. Although the results are still limited, we show that these analyses are not only useful to understand the normal and abnormal morphogenesis in humans and mice but also to provide clues that could correlate aspects of prenatal developmental events with postnatal diseases.

Pío del Río-Hortega: A Pioneer in the Pathology of Central Nervous System Tumors

The last 140 years have seen considerable advances in knowledge of central nervous system tumors. However, the main tumor types had already been described during the early years of the twentieth century. The studies of Dr. Pío del Río Hortega have been ones of the most exhaustive histology and cytology-based studies of nervous system tumors. Río Hortega's work was performed using silver staining methods, which require a high level of practical skill and were therefore difficult to standardize. His technical aptitude and interest in nervous system tumors played a key role in the establishment of his classification, which was based on cell lineage and embryonic development. Río Hortega's approach was controversial when he proposed it. Current classifications are not only based on cell type and embryonic lineage, as well as on clinical characteristics, anatomical site, and age.

Synchronous leiomyosarcoma and fibroma in a single ovary: A case report and review of the literature

Primary ovarian leiomyosarcoma (POLMS) is a rare disease. To the best of our knowledge, only 72 cases, including the present case, have been reported in the English literature, while synchronous POLMS and fibroma in a single ovary have not previously been reported at all. In the present study, a 46-year-old premenopausal woman was diagnosed with a mass in the left ovary in 2005. A total of 5 years after the diagnosis of this mass, the patient was admitted to hospital exhibiting lower abdominal pain, and two masses were observed in the left ovary. An exploratory laparoscopy was performed. Frozen section analysis led to a diagnosis of fibroma. Furthermore, the observed second mass was hypothesized to be a malignant form of the original fibroma. A hysterectomy and bilateral salpingo-oophorectomy were performed. Pathological reports following surgery revealed concurrent stage Ic POLMS and fibroma in the left ovary. A total of 13 months after the initial surgery, recurrent leiomyosarcoma was detected. Although the patient underwent multiple cytoreductive surgeries and chemotherapy cycles, as well as interstitial brachytherapy and conventional therapy, a poor state of health ensued. Due to the rarity of POLMS, particularly in combination with ovarian fibroma, the current report presents a detailed overview of the literature and discusses a number of histogenetic and clinical issues.

Primary intraosseous mucoepidermoid carcinoma of the jaw: Reappraisal of The MD Anderson Cancer Center experience

BACKGROUND

Mucoepidermoid carcinoma arises from major or minor salivary glands, making up 10% of salivary gland tumors. Intraosseous mucoepidermoid carcinomas are rare, and make up only 2% to 3% of all mucoepidermoid carcinomas. The t(11;19) and its CRTC1-MAML2 fusion gene transcript have been identified in mucoepidermoid carcinoma and are associated with a subset of mucoepidermoid carcinomas. The extent to which the transcript influences disease features and patient survival is unclear.

METHODS

We conducted a retrospective analysis of records for clinical features, surgical interventions, and prognoses. Reverse transcriptase-polymerase chain reaction (RT-PCR) and fluorescence in situ hybridization (FISH) used to assess the t(11;19) fusion gene in intraosseous mucoepidermoid carcinoma.

RESULTS

Twenty-five patients with intraosseous mucoepidermoid carcinoma treated between 1998 and 2013 were identified. The t(11;19) fusion gene transcript CRTC1-MAML2 manifested in 9 intraosseous mucoepidermoid carcinomas, whereas is was not detected in another 9 intraosseous carcinomas. Although the incidence of this fusion in mucoepidermoid carcinoma varies, it is generally accepted that more than 50% of this entity manifest the CRTC1-MAML2.

CONCLUSION

Intraosseous mucoepidermoid carcinoma diagnosis should be based on clinical and pathologic manifestations and complete resection is the first choice for patient treatment. The need for neck dissection and adjuvant treatment are debatable. Radiotherapy may improve prognosis and may be recommended in the postoperative period. Primary intraosseous mucoepidermoid carcinoma can manifest the fusion transcript in a subset of tumors. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1312-E1317, 2016.

Clonality analysis of combined Brenner and mucinous tumours of the ovary reveals their monoclonal origin

The derivation of ovarian intestinal-type mucinous tumours is not well established. Some are derived from teratomas but the origin of the majority is not clear. It has been recently proposed that the non-germ cell group may be derived from Brenner tumours, as the association of a mucinous tumour with a Brenner tumour is frequently observed. In order to explore the histogenesis of these neoplasms, we undertook a clonality analysis of the two components of ten combined Brenner and mucinous tumours using a human androgen receptor gene (HUMARA) assay. All eight informative cases of ten showed a concordant X-chromosome inactivation pattern between the two tumour components, indicative of a shared clonal origin (p = 0.0039). Microsatellite genotyping in five of the combined tumours displayed an identical heterozygous pattern with paired Fallopian tube tissue, indicative of a somatic cell origin. In addition, paired box protein 8, a highly sensitive Müllerian epithelial marker, was not detected by immunohistochemistry in either tumour component in any of the ten tumours, suggesting that this subset of mucinous tumours does not originate from Müllerian-derived epithelium. In conclusion, this study demonstrates that in combined mucinous and Brenner tumours, there is a shared clonal relationship between the two different tumour components and suggests that some pure mucinous tumours may develop from a Brenner tumour in which the Brenner tumour component becomes compressed and obliterated by an expanding mucinous neoplasm.

Unusual apocrine carcinoma with neuroendocrine differentiation: a cutaneous neoplasm may be analogous to neuroendocrine carcinoma with apocrine differentiation of breast

Cutaneous apocrine carcinoma (AC) is a rare adnexal neoplasm that histologically can mimic breast carcinoma metastatic to the skin or apocrine carcinoma arising in ectopic breast tissue. As extremely rare condition, neuroendocrine differentiation may be observed in AC although its etiology and pathogenesis is still unclear. We report here a case of unusual AC with neuroendocrine differentiation in right labium majus pudenda. A 43-year-old woman presented with a 6-month history of an asymptomatic pea-sized brownish nodule in right labium majus pudenda without enlargement of inguinal lymph nodes and bilateral breast nodules. The mass was totally resected. Microscopically, the tumor was solitary and located in the deep dermis without epidermal connection. Tumor cells were arranged in a micronodular or formed massive solid nests separated by densely fibroblastic stroma. Scattered glandular or rosette-like structures were identified within the tumor nodules. Immunohistochemically, the tumor cells were diffusely positive to CK7, CEA, GCDFP-15, synaptophysin, estrogen and progesterone receptors. Part of tumor cells expressed androgen receptor, but they were negative to CK20, CK5/6, p63 and S-100. Because of its rarity and histogenesis complexity, there exist diagnostic challenges for pathologists to differentiate cutaneous AC with neuroendocrine differentiation from other carcinomas with apocrine or neuroendocrine features. Our case demonstrates that the tumor shares some features with mammary carcinoma and might originate from mammary-like sweat gland in anogenital region. The results suggest that, for the first time, primary cutaneous AC with neuroendocrine differentiation may be analogous to the mammary neuroendocrine carcinoma with apocrine differentiation in histological feature and biological behavior. Virtual Slides: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/7732276716685708.

Morphological and morphometric aspects of early life stages of piabanha Brycon gouldingi (Characidae)

Adult specimens of piabanha Brycon gouldingi were collected from Rio das Mortes (Mato Grosso, Brazil), adapted to captivity and induced to spawn at Buriti Fisheries (Nova Mutum, MT, Brazil). The early developmental stages of B. gouldingi were then characterized. Samples were collected at pre-determined times from oocyte extrusion to total yolk absorption. Oocyte diameter, total larval length (LT ) and yolk-sac volume were measured. The mean ± s.d. duration of embryo developmental of B. gouldingi was 13·90 ± 0·06 h at 26·40 ± 1·13° C. The mean ± s.d. oocyte diameter was 1·13 ± 0·06 mm with 54% of oocytes ranging from 1·11 to 1·20 mm. Seven stages characterized the early developmental phase of this species: zygote, cleavage, morula, blastula, gastrula, histogenesis-organogenesis and hatching, with unique features related to each stage. At hatching, the larvae measured 3·40 ± 0·07 mm, presented an elongated shape with yolk-sac volume of 0·46 ± 0·08 µl, non-pigmented eyes and exhibited swimming ability. When the yolk was completely absorbed at 55 h post-hatch, mean ± larval LT was 6·68 ± 0·65 mm, the eyes were highly pigmented and the teeth were visible. These are the first reported findings on the initial developmental stages of B. gouldingi and could be used to improve captive breeding management and conservation practices.

Recent advances in histogenesis research of lung neuroendocrine cancers: Evidence obtained from functional analyses of primitive neural/neuroendocrine cell-specific transcription factors

Small cell carcinoma (SmCC) and large cell neuroendocrine carcinoma (LENEC) are categorized as neuroendocrine cancers (NECs) of the lung and have extremely poor prognoses. The lack of an effective therapeutic strategy against SmCC and LCNEC is a serious issue. Because the regulation of the cellular phenotype is complicated by the actions of various transcription factors, investigations into the function of neural/neuroendocrine cell-specific transcription factors are important for elucidating the cellular characteristics and histogenesis of SmCC and LCNEC and for establishing innovative therapeutic strategies against them. In this review, the functions of ASCL1, NeuroD1, REST, TTF1, and class III/IV POU, that are specifically and highly expressed in lung NECs, are introduced. These transcription factors transactivate and/or transrepress various genes and are involved in neural progenitor phenotyping, neuroendocrine and stem cell marker expression, and epithelial-to-mesenchymal transition. Based on the evidence that certain carcinoids express ASCL1, NeuroD1, TTF1, and class III/IV POU and that lung NECs can develop from non-NE cells/non-NEC cells, the relationships among lung NECs, carcinoid tumors, and non-NECs are discussed. Finally, a model of the histogenesis of lung NECs in view of similarities in the expression of primitive neural/neuroendocrine cell-specific transcription factors is proposed.

Squamous cell carcinoma of parotid gland associated with concurrent lymphoepithelial cysts and lymphoepithelial lesion: case report and proposed histogenesis

Lymphoepithelial cyst and lymphoepithelial lesion have similar histologic features and an affinity for the parotid gland. Though considered as different entities, both conditions arise from heterotopic salivary epithelial rests or inclusions in intra- or peri-parotid lymph nodes. We present a case of squamous cell carcinoma of parotid gland associated with concurrent lymphoepithelial cyst and lymphoepithelial lesion in a patient who was not infected with human immunodeficiency virus. We propose that lymphoepithelial cyst and lymphoepithelial lesion have a similar histogenesis.

How does secondary neoplasm arise from mature teratomas in growing teratoma syndrome of the ovary? A report of two cases

Development of secondary neoplasm in mature teratomas is a long-term potential risk in growing teratoma syndrome (GTS) of the ovary. The origin or histogenesis of the secondary neoplasm, however, is scarcely understood. We herein report two cases of GTS that began secondary neoplastic change 10 and 22 years after initial presentation. In one case, microscopic carcinoids were scattered over various mature elements derived from three germ cell layers: some were close to the intestinal-type glands or adipose tissue and others lay in the glia. This implies that these carcinoids multicentrically originated from pluripotent stem cells that had been latent in various mature tissues. In contrast, the other case had only one focus of intestinal-type tubular adenocarcinoma, measuring 5 mm in diameter, adjacent to the intestinal-type glands. Malignant transformation of intestinal-type glands is most likely to account for this adenocarcinoma. In both cases, peritoneal mature teratomas also contained foci of endometriosis, almost exclusively in their glial components. In conclusion, the present cases suggest two diverse histogenesis of secondary neoplasm in GTS and a specific role of glia in the development of endometriosis in peritoneal teratomas.

Clinical and pathological features of lipoleiomyoma of the uterine corpus: a review of 76 cases

BACKGROUND

Uterine lipoleiomyoma is a rare and specific type of leiomyoma with a considerable amount of adipocytes.

AIMS

The aim of the study was to investigate the clinical, pathological and immunohistochemical features of lipoleiomyoma of the uterine corpus, and review its histogenesis and differential diagnosis from other neoplastic and non-neoplastic lesions in order to obtain a detailed profile of this somewhat uncommon lesion.

STUDY DESIGN

Descriptive study.

METHODS

This study is a retrospective analysis of 70 consecutive women with 76 lipoleiomyomas, who underwent surgery mainly for uterine leiomyoma and gynecological carcinomas between January 2000 and April 2013. Clinical and pathological information was obtained from medical records. Immunohistochemistry was applied in selected cases. Parametric methods were used to compare clinical and pathologic features.

RESULTS

The patients ranged in age from 34 to 77 years (mean 55.49 years). Lipoleiomyomas ranged from 0.5 to 55 cm in diameter (mean 5.50 cm). Typical macroscopic and microscopic features were noted. Sixty-nine (90.7%) tumors were in the uterine corpus and five (6.5%) were in the cervix. One broad ligament tumor and one retroperitoneal tumor were also studied. No tumors displayed cytologic atypia, mitosis, necrosis, calcification, or other degenerative changes. Immunohistochemically, the adipose tissue element was positive for vimentin, desmin, S100 protein, estrogen (ER), progesterone (PR), and Ki-67. Among patients with lipoleiomyomas, 53 cases (75.7%) had different types of lesions associated with hyperestrogenic status, such as adenomyosis, endometriosis, endometrial hyperplasia, and polyps, complex atypical endometrial hyperplasia, and gynecologic carcinomas. The follow-up period ranged from one to eight years (mean 4.6 years). There were no recurrences or tumor-related fatalities.

CONCLUSION

In the present study, the lipoleiomyomas were seen more frequently in patients with adenomyosis, endometriosis, endometrial hyperplasia, polyps, and various gynecologic carcinomas. Lipoleiomyoma of the uterus seems to have a benign clinical course.

Intraspinal dural-based primary osteoblastoma with aneurysmal bone cyst-like change

Osteoblastoma is a benign bone-forming neoplasm that occurs commonly in the posterior elements of the spine and the sacrum. However, so far there has been no report of intradural osteoblastoma described in the literature. We present a unique case of intraspinal dural-based osteoblastoma with aneurysmal bone cyst-like change without evidence of vertebral involvement. An 11-year-old Chinese girl presented with a 3-month history of gradually progressive back pain and a weakness of both lower limbs. Thoracic MRI revealed a well-demarcated subdural mass at the T5 level with heterogeneous enhancement. Histologically, the tumor was found to be attached to the dura and composed of numerous osteoid spicules and trabecular bone with diffusely scattered osteoclast-type, multinucleated giant cells. Ectactic blood vessels and blood-filled cystic spaces were also observed. A diagnosis of primary intraspinal dural-based osteoblastoma with aneurysmal bone cyst-like change was made. To our best knowledge, this is possibly the first case of primary osteoblastoma arising from meninges. Meningeal osteocartilaginous tumors are rare, with obscure histogenesis. The differential diagnosis of osteoblastoma in unusual locations is difficult and the confirmation of diagnosis should be cautiously made. Awareness of dural-based osteoblastoma and its histological features is important to avoid a diagnostic pitfall caused by histological similarities to other intra-craniospinal lesions with osteoid differentiation or bone formation.

Cytokeratin 7/19 expression in N-diethylnitrosamine-induced mouse hepatocellular lesions: implications for histogenesis

Hepatocellular carcinoma (HCC) is a common malignancy with poor clinical outcome, whose histogenesis is the subject of intense debate. Specifically, expression of cytokeratins (CKs) 7 and 19, associated with aggressive biological behaviour, is proposed to reflect a possible progenitor cell origin or tumour dedifferentiation towards a primitive phenotype. This work addresses that problem by studying CKs 7 and 19 expression in N-diethylnitrosamine (DEN)-induced mouse HCCs. ICR mice were divided into six DEN-exposed and six matched control groups. Samples were taken from each group at consecutive time points. Hyperplastic foci (13 lesions) occurred at 29-40 weeks (groups 8, 10 and 12) with diffuse dysplastic areas (19 lesions) and with one hepatocellular adenoma (HCA) (at 29 weeks). HCCs (4 lesions) were observed 40 weeks after the first DEN administration (group 12). CKs 7 and 19 showed identical expression patterns and located to large, mature hepatocytes, isolated or in small clusters. Hyperplastic foci and the single HCA were consistently negative for both markers, while dysplastic areas and HCCs were positive. These results support the hypothesis that CKs 7 and 19 expression in hepatocellular malignancies results from a dedifferentiation process rather than from a possible progenitor cell origin.

Competing views on cancer

Despite intense research efforts that have provided enormous insight, cancer continues to be a poorly understood disease. There has been much debate over whether the cancerous state can be said to originate in a single cell or whether it is a reflection of aberrant behaviour on the part of a 'society of cells'. This article presents, in the form of a debate conducted among the authors, three views of how the problem might be addressed. We do not claim that the views exhaust all possibilities. These views are (a) the tissue organization field theory (TOFT) that is based on a breakdown of tissue organization involving many cells from different embryological layers, (b) the cancer stem cell (CSC) hypothesis that focuses on genetic and epigenetic changes that take place within single cells, and (c) the proposition that rewiring of the cell's protein interaction networks mediated by intrinsically disordered proteins (IDPs) drives the tumorigenic process. The views are based on different philosophical approaches. In detail, they differ on some points and agree on others. It is left to the reader to decide whether one approach to understanding cancer appears more promising than the other.

A clinicopathologic study on calcifying epithelial odontogenic tumor: with special reference to Langerhans cell variant

BACKGROUND

Calcifying epithelial odontogenic tumour (CEOT) is a rare benign odontogenic tumour, and its Langerhans cell variant is even rarer. Due to the limited number of recorded cases, the biological behaviour and histogenesis of the Langerhans cell variant of CEOT are not yet fully understood. Thus, the correlation between conventional CEOT and the Langerhans cell variant remains to be clarified.

MATERIAL (CASES)

Eight cases of CEOT including 2 cases of Langerhans cell variant were clinicopathologically studied and the English language literature was reviewed. Langerhans cells were detected in 2 cases of conventional CEOT and in 2 cases of Langerhans cell variant by immunohistochemistry.

RESULTS AND FINDINGS

In the 6 cases of conventional CEOT, 5 tumours involved the premolar and molar region and the anterior portion of the mandible was affected in 1 case. Four patients were followed for 2-7 years and did not show any sign of recurrence. A review of the English language literature revealed 5 cases; combined with the present 2 new cases, a total of 7 cases of Langerhans cell variant of CEOT were collected. The patients were all Asian. Six tumours occurred in the maxilla and 1 in mandible; all mainly involved the anterior region of the jaws. Five patients were followed for 2-10 years and did not show any evidence of recurrence. Langerhans cells can be seen in both the conventional and the Langerhans cell variant of CEOT; however, increased numbers of Langerhans cells are seen in the latter.

CONCLUSIONS

Although the Langerhans cell variant of CEOT is a rare entity and behaves similarly to the conventional type, it could show unique clinical and histologic features that may pose problems for differential diagnosis.

VIRTUAL SLIDES

http://www.diagnosticpathology.diagnomx.eu/vs/1979090740113894.