Primary pulmonary hyalinizing spindle cell tumor with giant rosettes: A clinicopathological and immunohistochemical study of 2 cases

Two cases of primary intrapulmonary hyalinizing spindle cell tumor with giant rosettes are presented. The patients are one woman and one man ages 37 and 42 years respectively. Both patients presented with non-specific symptoms of cough, dyspnea, and chest pain. Imaging revealed the presence of an intrapulmonary mass. One tumor was located in the left lower lobe while the other tumor was in the right upper lobe. Both patients underwent lobectomy. The tumors ranged from 2.4 to 3.0 cm in greatest dimension and were characterized by the presence of a bland spindle cell proliferation with areas of hyalinization and the presence of the so-called giant rosettes. Immunohistochemical stains were performed and the spindle cell component show positive staining for vimentin and negative staining for Bcl-2, CD34, STAT6, p40. Keratin immunohistochemical stain highlighted the entrapped alveolar epithelium while S-100 protein showed weak focal staining in the spindle cells. Both patients have remained alive and well without evidence of recurrence or metastasis for a period of 6 to 14 months post-surgical resection. The cases herein presented highlight the ubiquitous distribution of this tumor and underscores the importance of keeping this particular tumor in the differential diagnosis of spindle cell tumors of the lung.

Lung Metabolism and Inflammation during Mechanical Ventilation; An Imaging Approach

Acute respiratory distress syndrome (ARDS) is a major cause of mortality in critically ill patients. Patients are currently managed by protective ventilation and alveolar recruitment using positive-end expiratory pressure (PEEP). However, the PEEP's effect on both pulmonary metabolism and regional inflammation is poorly understood. Here, we demonstrate the effect of PEEP on pulmonary anaerobic metabolism in mechanically ventilated injured rats, using hyperpolarized carbon-13 imaging. Pulmonary lactate-to-pyruvate ratio was measured in 21 rats; 14 rats received intratracheal instillation of hydrochloric-acid, while 7 rats received sham saline. 1 hour after acid/saline instillation, PEEP was lowered to 0 cmH2O in 7 injured rats (ZEEP group) and in all sham rats; PEEP was continued in the remaining 7 injured rats (PEEP group). Pulmonary compliance, oxygen saturation, histological injury scores, ICAM-1 expression and myeloperoxidase expression were measured. Lactate-to-pyruvate ratio progressively increased in the dependent lung during mechanical ventilation at ZEEP (p < 0.001), but remained unchanged in PEEP and sham rats. Lactate-to-pyruvate ratio was correlated with hyaline membrane deposition (r = 0.612), edema severity (r = 0.663), ICAM-1 (r = 0.782) and myeloperoxidase expressions (r = 0.817). Anaerobic pulmonary metabolism increases during lung injury progression and is contained by PEEP. Pulmonary lactate-to-pyruvate ratio may indicate in-vivo neutrophil activity due to atelectasis.

[Lipoid proteinosis of Urbach-Wiethe: a case report]

Lipoid proteinosis or Urbach-Wiethe disease is a rare autosomal recessive mucocutaneous disorder caused by mutation in the EMC1 gene. Hoarseness is observed in early childhood associated with infiltration and thickening of skin. Multiple systemic manifestations develop involving mucosal deposition of hyalin material. We describe a 12-year-old boy with typical manifestations: a hoarse voice, thick skin with yellowish papules, including the typical disposition on the margin of the eyelids, infiltration of the tongue and lips, and varicella-like scars. Histopathological examination revealed deposition of hyaline substance with PAS-positive diastase-resistance at the dermoepidermal junction and around vessels. Ultrastructural study showed considerable thickening of the basal lamina of vessels besides the intense deposition of amorphous material in the dermis. Genetic analysis was not available.

Development of a Hodgkin disease tumor in the neck of a patient who previously had undergone complete excision of a hyaline-vascular Castleman disease neck mass

Castleman disease is an uncommon cause of a neck mass. A benign lymphoproliferative disorder, it may be seen as a self-limited unicentric process or as a fulminant multicentric disease with systemic symptoms. The association between Hodgkin disease and Castleman disease has been debated extensively, but this association is rare. The associated Hodgkin disease frequently has been of the interfollicular subtype and typically has coexisted with the multicentric plasma-cell variant of Castleman disease. We report a case of mixed-cellularity Hodgkin disease of the neck in a patient previously diagnosed with hyaline-vascular-type Castleman disease who had undergone complete excision of a neck mass 2 years earlier.

Cytologic findings of low grade endometrial stromal sarcoma with sex cord-like differentiation: a case report

BACKGROUND

To report the cytologic characteristics of low grade endometrial stromal sarcoma with sex cord-like differentiation.

CASE

A 49-year-old woman presented with hypermenorrhea, menorrhalgia and anemia. With a diagnosis of degenerated leiomyoma of the uterus, simple total hysterectomy was conducted. Histologic examination revealed cells with ovoid to short, spindle-shaped nuclei resembling endometrial stromal cells proliferating in a space-occupying manner and compressing and partially infiltrating the myometrium. Some tumor cells were arranged in sex cord-like form, and hyalinization was observed in the center of the cord. Low grade endometrial stromal sarcoma with sex cord-like differentiation was diagnosed. Touch imprint cytologic examination of the tumor showed cells containing scanty cytoplasm and ovoid to spindle-shaped nuclei with little atypia; they were scattered individually, aggregated in clusters, or arranged in cord or glandular form. Hyaline-like substance was present in abundance. The histologic characteristics of the endometrial stromal sarcoma with sex cord-like differentiation were confirmed by touch imprint cytology of the tumor.

CONCLUSION

In this case of low grade endometrial stromal sarcoma with sex cord-like differentiation, cytologic examination revealed hyaline substance and tumor cells aligned in cord or glandular form.

Anaplastic carcinoma of the pancreas with rhabdoid features and hyaline globule-like structures

A 59-year-old Japanese man presented with a giant submucosal tumor with ulceration during follow-up of duodenal ulcer. Pancreaticoduodenectomy was undertaken, and subsequent histological examination of the tumor disclosed anaplastic carcinoma of the pancreas head. The carcinoma components contained adenocarcinoma and squamous cell carcinoma. Additionally, undifferentiated spindle or pleomorphic cells were seen in continuity with the carcinoma component. Undifferentiated neoplastic cells with rhabdoid features and with hyaline globule-like structures positive for PAS stain with diastase pretreatment were also observed. Immunohistochemically, cytoplasmic inclusions corresponding to rhabdoid features showed aggregates of vimentin. Ultrastructurally, hyaline globule-like structures corresponded to lysosomes. Finally, we report here the first case of anaplastic carcinoma of the pancreas with hyaline globule-like structures.

Oxidative stress is related to the formation of Antoni B patterns and eosinophilic hyaline droplets in schwannomas

Schwannomas, particularly of vestibular origin, often accompany degenerative hypocellular areas known as Antoni B patterns; however, the detailed mechanism is uncertain. Eosinophilic hyaline droplets (EHD), the substantial nature of which are autophagic vacuoles, preferentially appear in acoustic schwannomas and distribute around areas of Antoni B. We investigated their common background using schwannomas with (15 cases) or without (10 cases) EHD, and demonstrated that EHD showed selective immunoreactivity with an anti-nitrotyrosine antibody, suggesting the overproduction of nitric oxide in this condition. The expression of inducible nitric oxide synthase was emphasized in infiltrating macrophages around hyalinized vessels. Protein-bound 4-hydroxy 2-nonenal, another oxidative stress marker, was detected in Antoni B tissue, but not in EHD. Antibodies to cleaved caspase-3 and single strand DNA, indicators of apoptosis, did not label tumors cells in Antoni B areas as well as EHD-bearing cells. The morphology and the mitotically static state of EHD-laden cells are phenotypically similar to autophagic cell death; however, autophagy in normal cells is a cell survival strategy against starvation, so the possibility remains that EHD are formed in that context. In either case, schwannomas may show a characteristic autophagic change by an endogenous mechanism. Tumor growth in a narrow intracranial space and resultant ischemia by self-oppression were postulated to be an initial event, because ischemia-reperfusion injury is a major source of reactive oxygen species and ischemia is also a potent trigger of autophagy as well as of tissue degeneration. Moreover, potential roles of chemokines and hemosiderosis are discussed.

Hyaline globules (thanatosomes) in gastrointestinal epithelium: pathophysiologic correlations

Hyaline globules (HGs; thanatosomes) are well-defined morphologic and functional entities representing a degenerative phenomenon common to all cell types. We present the first quantitative and qualitative study of HGs in normal and pathologic gastrointestinal (GI) epithelium from a series of 2,230 biopsies. HGs were very rarely found in normal epithelium (1.1%), but their number increased significantly in specimens with ischemic injury (47%) and benign regenerative proliferation (70%). Their incidence in adenomatous polyps and adenocarcinomas was about 11% to 27%. Of the HGs, 2.9% contained nuclear fragments. Our results entirely support the unifying morphogenetic concept for HGs. The role of 2 obligatory morphogenetic factors for the generation of thanatosomes (propensity to apoptosis and heterophagy/autophagy) is confirmed. The nature of the third factor, ischemic conditions, is specified. Although a nonspecific microscopic phenomenon, HGs in the GI tract represented a relatively constant and useful histologic marker of enhanced cell turnover and ischemic injury.

Hyaline globule-like structures in undifferentiated sarcoma cells of malignant müllerian mixed tumor of the fallopian tube

Malignant müllerian mixed tumors (MMMTs) of the fallopian tube are very rare neoplasms, and we present such a case with unusual findings here. A 57-year-old Japanese woman, after she received a medical checkup, underwent salpingo-oophorectomy on the suspicion of ovarian cancer. At the time of operation, the main tumor was present predominantly in the fallopian tube. Microscopically, the tumor consisted of carcinoma and sarcoma components. The carcinoma showed moderately to poorly differentiated adenocarcinoma. The sarcoma consisted of predominantly undifferentiated sarcoma and focally rhabdomyosarcomatous cells with abundant eosinophilic cytoplasm. Immunohistochemically, the differentiation toward rhabdomyosarcoma was confirmed. Interestingly, the cytoplasm of undifferentiated sarcoma cells contained hyaline globule-like structures. These structures showed a positive reaction for PAS, and these structures were not digested by the diastase pretreatment. Ultrastructurally, hyaline globule-like structures corresponded to lysosomes. Finally, pathologists should keep in mind that undifferentiated sarcoma cells in MMMT of the fallopian tube may contain hyaline globule-like structures in the cytoplasm.

Myosin storage (hyaline body) myopathy: a case report

Myosin storage myopathy/hyaline body myopathy is a rare congenital myopathy, with less than 30 cases reported in the literature. It is characterised by the presence of subsarcolemmal hyaline bodies in type 1 muscle fibres and predominantly proximal muscle weakness. Recently, a single mutation (Arg1845Trp) in the slow/beta-cardiac myosin heavy chain gene (MYH7) was identified in four unrelated probands from Sweden and Belgium. The clinical severity and age of onset was variable, despite the same disease-causing mutation and similar histological findings. Here, we report the clinical and morphological findings of two brothers of English/Scottish background with the Arg1845Trp mutation in MYH7. This case report adds to the clinical description of this rare disorder and confirms that Arg1845Trp is a common mutation associated with this phenotype, at least in the White European population.

Ultrastructure of tubular casts

Tubular casts are found in a variety of conditions. Ultrastructural evaluation of casts has not been critically and systematically performed to define its usefulness. A total of 157 renal biopsies routinely processed for light microscopy (LM), immunofluorescence (IF), and electron microscopy (EM) were subjected to blind ultrastructural evaluation. The majority of the casts were in the distal nephron, and most of them (41.4%) were hyaline (HC). One-third (35%) of the cases showed admixed HC and granular casts (GC), and 25 cases (16%) had exclusively GC. In 7% of the cases, the morphology of the casts was distinctive enough to indicate specific composition. Four cases with red blood cell casts (5.6%) were associated with necrotizing glomerulopathy and IgA nephropathy. Four cases of myoglobulin casts were identified. Two cases with crystalized light-chain casts (1.3%) were associated with an underlying plasma cell dyscrasia. One case of acute pyelonephritis demonstrated polymorphonuclear cells casts (0.64%). A case of aminoglycoside toxicity revealed casts with myeloid bodies. Ultrastructural evaluation of casts may provide useful information that may be critical to establish or suggest a specific diagnosis.

Clear cell type of renal cell carcinoma with numerous hyaline globules: a diagnostic pitfall

A unique and never-before-published example of clear cell renal cell carcinoma (CRCC) found among 9000 primary renal cell tumors is presented. The tumor contained such a dense concentration of glassy hyaline globules (GHG) in the cytoplasm of the neoplastic cells that it overshadowed the morphology of the neoplasm. The resulting appearance of the tumor was quite misleading and different from the conventional CRCC. The GHG were 7-30 microm in diameter. They were glassy and pale to slightly eosinophilic in color in hematoxylin-eosin. The GHG stained positively with periodic acid-Schiff and negatively with silver and Hale's colloidal iron. Immunohistochemically, they were also negative for anti Mycobacterium bovis antigen. At the ultrastructural level, the GHG were formed by an amorphous mass of stellate shape. The GHG were localized within rough endoplasmic reticulum. Molecular genetically, mutation of the distal part of exon 3 of the VHL gene causing elongation of the VHL protein was found in the tumor, thus confirming the diagnosis of CRCC.

Occurrence of hyaline droplets in renal biopsy specimens: an ultrastructural study

Hyaline droplets are apical cytoplasmic vesicles containing an accumulation of electron-dense amorphous materials surrounded by a unit membrane. Hyaline droplets may originate from apical vesicles after conversion to osmotic vesicles and loss of internally lined glycocalyx. They are found in the proximal tubular epithelium in biopsies from patients with renal diseases; however, their biological importance is not well understood. We reviewed ultrastructural pathology records of 140 renal biopsy patients to determine the occurrence and relevance of hyaline droplets. Of the cases, 14 (10%) showed the presence of hyaline droplets in proximal tubular epithelium. The distribution of cases were 8 of the 19 (42%) with minimal change nephritic syndrome, 2 of the 37 (5%) with IgA nephropathy, 2 of the 4 (50%) with membranous glomerulonephropathy, 1 of the 4 (25%) with tubulointerstitial nephritis, and 1 of the 1 (100%) with acute renal failure. The droplets were frequently found in male patients (86%), never in children, and were mostly associated with tubular necrosis (8 of 14 cases; 56%). Many hyaline droplets were observed in the cytoplasm of necrotic proximal tubular epithelial cells, and even when tubular necrosis was not evident, the proximal tubular epithelial cells containing hyaline droplets showed degenerated microvilli and decreased basal interdigitations. These results suggest that hyaline droplets could be one marker of renal tubular necrosis and a sign of functional disorder of protein reabsorption by degenerating proximal tubular epithelium.

Sclerosing mucoepidermoid carcinoma of the oral cavity

Sclerosing mucoepidermoid carcinoma (SMEC) with eosinophilia is a rare but distinctive tumor usually affecting the thyroid. SMEC involvement of salivary gland is exceptional, with only six cases in the literature. We present here the first case of an intermediate-grade SMEC, arising from the intraoral minor salivary glands. A particularly interesting finding is the cytoplasmic accumulation of eosinophilic hyaline granules in carcinoma cells, similar to aberrant zymogen-like granules previously described in salivary sclerosing polycystic adenosis.

Localisation of sulphated glycoconjugates during hyaline layer formation in rat molars by ultrastructural cytochemistry

In order to study the presence of sulphated glycoconjugates in the first mineralised layer juxtaposed to the root dentine (the hyaline layer), we have examined the early stages of molar root development by ultrastructural cytochemistry using Cuprolinic Blue combined with enzymatic pretreatment. Upper molars from 10 to 13 day-old Wistar rats were fixed in 2.5% glutaraldehyde containing 0.05% Cuprolinic Blue in 25 mM sodium acetate, pH 5.6, containing 0.3 M MgCl2. Some specimens were previously treated with heparitinase or chondroitinase ABC. Our results showed sulphated glycoconjugate--Cuprolinic Blue complexes that appeared as electron opaque ribbon-like deposits in the unmineralised hyaline layer. Few complexes were detected adjacent to the dentinal surface. These complexes were removed by heparitinase, indicating that they contained heparan sulphate chains. In contrast, the complexes found in unmineralised cementum and root dentine were removed by chondroitinase, indicating that they contained chondroitin or dermatan sulphate chains. The complexes decreased after the initiation of mineralisation of hyaline layer and root dentine and they were no longer present in stages of fully mineralisation. We conclude that the hyaline layer only contains sulphated glycoconjugates prior to mineralisation, and that they may play a role in the regulation of the mineralisation.

Ultrastructural changes in arteriovenous malformations after gamma knife surgery: an electron microscopic study

Object.The authors analyzed morphological alterations at the subcellular level by undertaking transmission electron microscopy in arteriovenous malformations (AVMs) after gamma knife surgery (GKS).

Methods.Histological, immunohistochemical, and electron microscopic investigations were performed in a series of pathological specimens obtained in seven patients. The patients harbored cerebral AVMs that had been previously treated with GKS and had suffered subsequent bleeding 10 to 52 months after treatment.

Histological studies revealed spindle cell proliferation in the connective tissue stroma and in the subendothelial region of the irradiated AVM vessels. Electron microscopy demonstrated different ultrastructural characteristics of this spindle cell population. There were cells with a smooth-edged oval nuclei surrounded by massive bundles of collagen fibers in the extracellular matrix. Other cells with the same nuclear morphology contained abundant intracytoplasmic filaments. Nuclear deformation was connected to a fibrillary system developed within the cytoplasm, and peripheral attachment sites were related to an extracellular layer of basement membrane—like material arranged parallel to the cell border. Also present were cells containing well-developed cisterns of rough endoplasmic reticulum and dense bodies at the periphery of the cytoplasm with folded, irregular nuclei.

Conclusions.The ultrastructural and histological characteristics of the spindle cell population in the GKS-treated AVMs are similar to those designated as myofibroblasts in wound healing processes and pathological fibromatoses. Because similar cell modifications have not been demonstrated in control nonirradiated AVM specimens, these myofibroblasts may contribute to the shrinking process and final occlusion of AVMs after radiosurgery.

Sertoli cell nodules in the undescended testis: a histochemical, immunohistochemical, and ultrastructural study of hyaline deposits

AIMS

To document the morphology, immunohistochemical staining properties, and ultrastructural features of hyaline material in Sertoli cell nodules of undescended testis and contrast them with those of sex cord tumour with annular tubules (SCTAT), which is histologically similar. To highlight the need to distinguish these nodules from other Sertoli cell hyperplasias, such as intratubular Sertoli cell proliferations, which occur in specific clinical contexts.

MATERIALS/METHODS

A retrospective study of 46 orchidectomy specimens from cryptorchid testes, 27 of which contained Sertoli cell nodules. Special histochemical stains, immunohistochemical stains for type IV collagen and fibronectin, and ultrastructural examination of the hyaline material were performed using tissue from paraffin wax embedded tissue blocks.

RESULTS

The hyaline deposits in SCTAT and Sertoli cell nodules had similar staining patterns-periodic acid Schiff (PAS) and PAS-diastase positivity with variable staining of Martius scarlet blue and Masson trichrome. Type IV collagen immunoreactivity was seen in hyaline areas, although fibronectin was negative. Electron microscopy of hyaline areas confirmed a compact matrix identical to components of the basement membrane in the adjacent seminiferous tubules.

CONCLUSION

This study describes an unusual form of Sertoli cell proliferation in undescended testes, which must be distinguished from Sertoli cell tumours and other forms of proliferation. In addition, the hyaline material within Sertoli cell nodules in the cryptorchid testis is histochemically, immunohistochemically, and ultrastructurally consistent with both matrix and fibrous components of seminiferous tubule basement membranes. Increased production of basement membrane material, with subsequent invagination into tubules, is the most likely origin of this material.

Changes in the periodontal ligament after experimental tooth movement using high and low continuous forces in beagle dogs

The aim of this study was to evaluate histological changes in the periodontal structures of beagle dogs after using high and low continuous forces during experimental tooth movement. An orthodontic appliance was placed on the second premolar and the first molar by exerting a continuous and constant reciprocal force of 25 cN on one side and 300 cN on the other side of the mandible. Tooth movement was recorded weekly. Dogs were sacrificed after one, four, 20, 40, and 80 days for histological evaluation. Hematoxylin and eosin (HE) staining was used for tissue survey, staining for alkaline phosphatase as a marker was used for active osteoblasts, and tartrate-resistant acid phosphatase staining was used for osteoclasts. After 24 hours, the remodeling process had already started at the pressure and tension side, and in some samples hyalinization was found. In contrast to earlier studies, hyalinization was found throughout the entire experimental period, both in molars and in premolars. In the periodontal ligament of some teeth, small patches of hyalinization were found at the pressure side, mostly located buccally or lingually of the mesiodistal plane, whereas others showed large areas of necrotic tissue. It is concluded that hyalinization limits tooth movement, but there is no relationship with the force level.

Autosomal dominant hyaline body myopathy: Clinical variability and pathologic findings

OBJECTIVE

To report clinical, morphologic, and immunohistochemical studies on autosomal dominant, clinically nonprogressive, and not previously described progressive forms of hyaline body (HB) myopathy (HBM) in a Saudi Arabian kindred.

RESULTS

Muscle biopsies from four patients showed HB in type 1 fibers; they were positive for ATPase at pH 4.3/4.6 and for heavy chain slow myosin (HCSM); some HB were HCSM negative. HB were nonreactive for alphaB-crystallin, ubiquitin, tropomyosin, actins, desmin, and components of sarcolemma. Ultrastructurally, HB were granular and filamentous or amorphous, often with fragments of sarcomeres, and surrounded by a zone of sarcomeric disorganization. All biopsies showed "myopathic" changes, angulated neurogenic fibers, and fiber type grouping. There was no correlation between HB and course of disease; the progressive cases displayed more severe myopathic features.

CONCLUSIONS

Formation of hyaline bodies in hyaline body myopathy is associated with either myolysis or defective incorporation of heavy chain slow myosin into the cytoskeleton. Hyaline bodies very likely contain additional unidentified proteins. Neurogenic factors are also involved in the hyaline body myopathy pathogenesis.

Histopathologic comparison of normal and hyperplastic condyles

OBJECTIVE

The aim of this study was to compare normal and hyperplastic mandibular condyles using two different histopathologic staining techniques.

STUDY DESIGN

Nine cases of condylar hyperplasia and 13 normal cases were studied after hematoxylin and eosin and silver staining.

RESULTS

There was a significant difference between the two groups in the thickness of the hyperplastic cartilage layer of condylar soft tissue (P = 0.017). Also, the number of argyrophilic nucleolar organizer regions was significantly higher in the condylar hyperplasia case group (P = 0.0001). No significant differences could be demonstrated in cartilage island frequency, penetration depth, and distribution in the cancellous bone of condyles.

CONCLUSION

The thickness of the hyperplastic cartilage layer appears significantly increased in condylar hyperplasia. In addition, argyrophilic nucleolar organizer region count may be useful in histopathological identification of condylar hyperplasia.

Pathologic evidence of degeneration as a primary cause of rotator cuff tear

Histopathologic, histochemical, and morphometric studies were done on 80 medial stumps of torn rotator cuff tendons to clarify the cause of tears. A high prevalence and diffuse distribution of degenerative changes were observed in the rotator cuff tendons including thinning and disorientation of collagen fibers, myxoid degeneration, hyaline degeneration, chondroid metaplasia, calcification, vascularproliferation, and fatty infiltration. No distinct inflammatory reaction was observed. Thinning and disorientation of collagen fibers, myxoid degeneration, and hyaline degeneration were seen in all cases. All changes except vascular proliferation and fatty infiltration were more pronounced in the middle to deep layers of the tendons than in the superficial layer. The collagen fibers were disoriented in the deep layer of the tendons, shown by microscopic image analysis. The frequency and distribution of thinning and disorientation of collagen fibers, myxoid degeneration, and hyaline degeneration suggest that these are early degenerative processes. Chondroid metaplasia and calcification may be chronic pathologic changes that occur after tearing regardless of the type of tear. Preexisting degenerative change in the middle and deep layers of the tendon in association with microtrauma seems to be the main cause of rotator cuff tears.

Hyalinizing spindle cell tumor with giant rosettes and low-grade fibromyxoid sarcoma: an immunohistochemical and ultrastructural comparative investigation

Hyalinizing spindle cell tumor with giant rosettes (HSCTGR) and low-grade fibromyxoid sarcoma (LGFMS) are 2 variants of fibrosarcoma, which share several clinicopathologic features. This study compares the light microscopic, immunohistochemical, and ultrastructural features of 2 examples of HSCTGR and 3 of LG FMS to determine the degree of overlap of these 2 tumors. HSCTGR were composed of bland spindle cells within hyalinized to myxoid stroma. Scattered throughout the lesions were characteristic rosette-like structures, formed by a central collagenous core surrounded by spindled neoplastic cells. LGFMS consisted of a mixture of fibrous and myxoid areas, composed of fibroblast-like cells arranged in a swirling, whorled growth pattern. Immunohistochemical analysis showed diffuse positivity for vimentin in all cases, while few scattered tumor cells stained for CD57, CD34, factor XIIIA, and actin. The extracellular matrix showed intense positivity for type IV collagen, laminin, and fibronectin, with the exception of myxoid areas of LGFMS and the central core of the giant rosettes in HSCTGR. Ultrastructurally, both tumor types were composed of cells with the features of fibroblasts, embedded in a collagenous stroma with irregular deposits of amorphous basal lamina-like substance. In conclusion, HSCTGR and LGFMS share similar immunophenotypic and ultrastructural features, and together with other fibrosing fibrosarcomas, like sclerosing epithelioid fibrosarcoma, may constitute a subset of fibrosarcomas formed by fibroblasts capable of producing large amounts of basal lamina-like material.

Identification and partial characterization of two inducible gelatin-cleavage activities localized to the sea urchin extraembryonic matrix, the hyaline layer

We have identified two inducible, gelatin-cleaving activities in the sea urchin extraembryonic matrix, the hyaline layer. Isolated hyaline layers, incubated in the presence of benzamidine, were devoid of gelatin-cleavage activities with apparent molecular mass less then 80k. However, when layers were incubated for 9-11 h in the absence of benzamidine, gelatin-cleavage activities, with apparent molecular mass 40- and 50k, were detected. Induction required the presence of NaCl and CaCl(2) at concentrations similar to those found in seawater and readdition of the reversible serine protease inhibitor benzamidine prevented induction. Both gelatin-cleaving activities were activated by calcium at a concentration similar to the calcium concentration found in seawater. Magnesium, also a major cationic species present in seawater, could not replace calcium as the activating ion. In addition, magnesium could not compete with calcium for binding to the gelatinases. Both cleavage activities showed substrate specificity and each failed to cleave bovine serum albumin, bovine hemoglobin or casein. Cleavage activity towards gelatin was inhibited by benzamidine and aminoethyl benzenesulfonyl fluoride, indicating that both activities belonged to the serine class of proteases. The induced 40-kDa activity displayed similar properties to those of a comigrating, gelatin-cleaving activity present in 69-h-old embryos.

Characterization of eosinophilic hyaline droplets in schwannoma

In schwannoma, degenerative structures, such as bizarre hyperchromatic nuclei, lipofuscin deposition, hemorrhage, edema, etc., are frequently encountered and are regarded as hallmarks of the benign nature of the neoplasm. Hyaline globules or eosinophilic hyaline droplets (EHDs) have been observed in a large variety of tumors, but they are rare histological manifestations of schwannoma, and the details have not been described as yet. We reviewed 171 cases of schwannoma of conventional histology. We classified them based on the sites where they occurred as follows: 43 acoustic nerves, 9 other cranial nerves, 30 spinal nerve roots, and 89 soft parts. We found EHDs in 8/43, 1/9, 1/30, 2/89 cases, respectively. The droplets were located in both the perikarya and processes. Ultrastructurally, they were electron-dense, round to ovoid organelles, and indistinguishable from secondary lysosomes. MIB-1 immunolabeling of the droplet-bearing cells was almost negative; however, they maintained a viable nuclear appearance without karyorrhexis, pyknosis or apoptotic changes. We therefore conclude that EHD is a new member of degenerative structures in schwannoma, and a hallmark of low growth potential. Furthermore, their higher frequency in acoustic schwannoma may suggest their distinct nature from those originated in the other sites. Possible relevance of EHDs and cellular senescence is also discussed.

Myofibrosarcoma (low-grade myofibroblastic sarcoma) with intracytoplasmic hyaline (fibroma-like) inclusion bodies

Myofibrosarcoma is a controversial neoplasm composed of cells with differentiation toward myofibroblasts. The authors report an unusual case of myofibrosarcoma in which, in addition to the characteristic features reported, tumor cells contained intracytoplasmic hyaline (fibroma-like) inclusion bodies. A 66-year-old man complained of a painless enlarged mass in his right shoulder over the previous 6 months. The tumor recurred 2 years after operation. On histologic examination, the tumor displayed diffusely infiltrative growth with isolation of individual skeletal muscle fibers. The tumor cells were most often arranged in an intersecting (herringbone) fascicular pattern but a vaguely storiform pattern was also observed. Cellularity varied from one area to another. The cells were spindle-shaped, with ill-define pale eosinophilic cytoplasm, and a wavy or tapering nucleus with fine chromatin and small nucleoli. Intracytoplasmic hyaline inclusion bodies of variable size, often located adjacent to the nucleus, were visible in numerous spindle and stellate cells. The mitotic index was 3/10 HPF. The tumor was scored as grade 1. Immunohistochemistry revealed positive staining to muscle-specific actin, desmin and vimentin in most tumor cells. Intracytoplasmic hyaline inclusion bodies did not react specifically to any one antibody, but showed a marked ring-like immune reaction, particularly to muscle-specific actin. Electron microscopy showed tumor cells with indented nuclei and small nucleoli, abundant rough endoplasmic reticulum, micropinocytotic vesicles, and longitudinally arranged fine filaments with focal electron-dense patches and subplasmalemmal plaques. The most striking feature was the presence of large, globular or ball-like, non-membrane-bound, randomly scattered clusters of fine filament, usually adjacent to the nucleus.

Exudative laryngeal diseases of Reinke's space: a clinicohistopathological framing

OBJECTIVE

To establish the relationship between the macroscopic and histologic diagnosis of nodules, polyps, and Reinke's edema of the true vocal folds and to propose a clearer clinical definition of them in the hope of settling the difference of opinion between otolaryngologists and pathologists.

DESIGN

Retrospective study

SETTING

Otolaryngology Department of "La Sapienza" University of Rome.

METHODS

The pathologic reports of 203 patients subjected to direct laryngoscopy were studied.

MAIN OUTCOME MEASURES

Examination of the histologic specimen of the epithelium and the chorion.

RESULTS

Microscopic examination revealed a high percentage of normal epithelium both for nodules (33.79%) and polyps (40.65%). No dysplasia was observed, whereas dysplasia was present in 10 cases of Reinke's edema (7 laryngeal intraepithelial neoplasia 1 and 3 laryngeal intraepithelial neoplasia II). Five different stages of histologic progression resulted from the examination of the chorion in both nodules and polyps.

CONCLUSIONS

Our suggestion is to consider polyps as "older" lesions and nodules as "younger" lesions. A polyp may be defined as an abnormal unilateral growth of vocal folds, a nodule as a bilateral growth situated between the anterior and medium third of the vocal fold, and Reinke's edema as a bilateral wound that extends to the whole of the true vocal fold.

Morpho-functional changes in human tendon tissue

Insertion tissue biopsies of right arm common extensor tendons from 11 patients with chronic lateral epicondylitis were processed for light and electron microscopy. The subjects were aged between 38 and 54 years (only one was 25). The specimens showed a variety of structural changes such as biochemical and spatial alteration of collagen, hyaline degeneration, loss of tenocytes, fibrocartilage metaplasia, calcifying processes, neovascularization and vessel wall modifications. Tissue alterations were evident in limited zones of the tendon fibrocartilage in which the surgical resection was generally visible. The areas where the degenerative processes were localized, were restricted and in spatial contiguity with morphologically normal ones. The observed cases presented histological and electron microscopic findings that characterize lateral epicondylitis as a degenerative phenomenon involving all tendon components.

CD34+ stromal cells and hyalinized vascular changes in the anal fibroepithelial polyps

AIMS

To elucidate the pathogenesis of the anal fibroepithelial polyp, we examined surgically resected lesions histopathologically.

METHODS AND RESULTS

Twenty-seven surgically resected anal fibroepithelial polyps were investigated histologically with an additional immunohistochemical examination using anti-CD34. For a control study, the surgical specimens of the anal canal showing non-polypoid lesions, obtained from haemorrhoidectomy (18 specimens) and rectectomy (five specimens) due to rectal cancer without anal canal involvement, were also analysed. We demonstrated characteristic spindle or stellate cells immunohistochemically positive for CD34 in the anal fibroepithelial polyps (24/27, 89%). The number of CD34+ cells was statistically related to the size of anal fibroepithelial polyps, although CD34+ stromal cells were recognized in the non-polypoid anal submucosa and haemorrhoids. We also found hyalinized vascular changes in the base of six anal fibroepithelial polyps examined. These features were not detected in the non-polypoid anal canal.

CONCLUSIONS

An increase in CD34+ stromal cells may play a role in the enlargement of anal fibroepithelial polyps. CD34+ stromal cells are suggested to be distinctive mesenchymal cells with a capability for tissue repair and overgrowth. The vascular impairment could be secondary change associated with localized tissue damage by abnormal traction.

Extra-abdominal desmoid fibromatosis: two familial cases with synchronous and metachronous multicentric hyalinizing nodules

AIMS

Extra-abdominal desmoid fibromatosis is an uncommon tumour. We present here two exceptional familial cases of extra-abdominal desmoid fibromatosis, one of which was synchronous and metachronous.

METHODS AND RESULTS

The first patient was a 37-year-old woman who had noted a tumour growing on the dorsum of her right foot when she was 12 years old. She underwent excision of the tumour but in the following year the tumour recurred locally and grew into multiple nodules. Subsequently, multicentric tumours appeared in her knee, distal and posterior aspects of her thigh, right back and right anterior shoulder. Polyostotic fibrous dysplasia of the femur and cranium was found on radiological examination. The second patient was a 74-year-old man, the uncle of the first patient. He underwent an excisional operation of a tumour on the internal malleolus surface of his fibula when he was 46 years old. The tumour recurred 7 years later and was excised. His post-operative course has been uneventful. The histology of the primary and recurrent tumours was distinctive and consistently showed hyalinizing scar-like features.

CONCLUSIONS

Familial cases of extra-abdominal desmoid fibromatosis with extensive multicentric lesions and distinctive hyalinizing scar-like features are described. Recently, attenuated familial adenomatous polyposis with familial desmoid fibromatosis has been recognized, and familial desmoid fibromatosis without adenomatous polyposis may also be one of its variants. Although the present cases have no history of colon polyposis or carcinoma, monitoring of the intestinal tract would seem to be indicated.

Juvenile hyaline fibromatosis: morphologic, immunohistochemical, and ultrastructural study of three siblings

Juvenile hyaline fibromatosis (JHF) is a rare hereditary disease characterized by the deposition of hyaline ground substance, which is described as fibrillogranular material on electron microscopy. Approximately 65 cases have been reported to date in the English language literature. We add 3 new cases of children presenting with multiple subcutaneous nodules. We have described the light microscopic, electron microscopic, and immunohistochemical features of these nodules. The characteristic chondroid appearance on light microscopy is imparted by large peripheral vesicles in the stromal cell cytoplasm. Ultrastructurally, the fibroblasts have shown evidence of defective synthesis of collagen, which is then deposited as fibrillogranular material in the matrix. Immunohistochemical studies have shown CD68+ macrophages and multinucleated histiocytic giant cells in all five specimens from our 3 cases. As far as we know, the presence of giant cells has not been reported in the literature. The main purposes of this report are to highlight the presence of macrophages as a constant constituent of the stromal cells in JHF and to review the literature on this subject.

Hyalinizing spindle cell tumor with giant rosettes: report of a case showing remarkable myofibroblastic differentiation

We examined the proliferative activity and the differentiation line of tumor cells in a case of "hyalinizing spindle cell tumor with giant rosettes" (HSCGR). A 6 cm tumor within the right deltoid muscle of a 58-year-old female was found by physical and radiographical examinations. A biopsy revealed the histological features of a spindle cell tumor with rosette-like structures. Wide excision was done under the diagnosis of HSCGR. The tumor presented as a gray-whitish, solid mass with focal pseudocystic degeneration. Immunohistochemically, the tumor cells were diffusely positive for vimentin and were also focally positive for S-100, but negative for desmin and alpha-smooth muscle actin. The cells stained positively for Ki-67 with even distribution, there being a correlation with the cellularity of the areas, with a labeling index ranging from 0.3 to 0.5%. In addition, flow cytometry revealed an almost normal diploid DNA pattern and 5.8% S-phase fraction, indicating low proliferative activity. Ultrastructurally, many tumor cells displayed discontinuous basal lamina, pinocytotic vesicles, dilated rough endoplasmic reticulum, and microfilaments with focal dense bodies. The main component of the rosette was collagenous fibrils with normal diameter and normal periodic banding. We interpreted this case of HSCGR as a low grade fibrosarcoma with remarkable differentiation of myofibroblastic lineage, and with focally accumulated, morphologically normal collagenous fibrils.

P-Nitrobenzoic acid alpha2u nephropathy in 13-week studies is not associated with renal carcinogenesis in 2-year feed studies

The objective of this study was to characterize the renal toxicity and carcinogenicity of p-nitrobenzoic acid in F344 rats. Dose levels in 13-week and 2-year studies ranged from 630-10,000 ppm and 1,250-5,000 ppm, respectively. At 13 weeks, renal lesions included minimal to mild hyaline droplet accumulation in male rats and karyomegaly in male and female rats. At 2 years, renal lesions included proximal tubule epithelial cell hyperplasia in male rats and oncocytic hyperplasia in high-dose male and female rats, and a decreased severity of nephropathy in males and females. The hvaline droplets in renal tubular epithelial cells of male rats at 13 weeks were morphologically similar to those described in alpha2u-globulin nephropathy. Using immunohistochemical methods, alpha2u-globulin accumulation was associated with the hyaline droplets. In addition, at 13 weeks, cell proliferation as detected by PCNA immunohistochemistry was significantly increased in males exposed to 5,000 and 10,000 ppm when compared to controls. Cytotoxicity associated with alpha2U-globulin nephropathy such as single-cell necrosis of the P2 segment epithelium or accumulation of granular casts in the outer medulla did not occur in the 13-week study. In addition, chronic treatment related nephrotoxic lesions attributed to accumulation of alpha2u-globulin such as linear foci of mineralization within the renal papilla, hyperplasia of the renal pelvis urothelium and kidney tumors were not observed. Although there was histologic evidence of alpha2u-globulin accumulation in male rats at 13 weeks, the minimal severity of nephropathy suggests that the degree of cytotoxicity was below the threshold, which would contribute to the development of renal tumors at 2 years.

On the functional organisation of hyaline articular cartilage

Function of agonists and antagonists and the centering effect of the muscles on the connected joint result in constant changes of the site of load. Based on a model it is assumed that chondric cells organise in form of "functional units" within the single layers of the hyaline tectorial cartilage. In each case a small number of those units is subject to the rhythm of load and relief in a fixed period of time given. After 24-hour-culture of small pieces of cartilage in Ham's F-10 medium erected cilia are found on the predominantly ciliated chondrocytes with this indicating relief of pressure. In these cells massive glycogen synthesis and an active Golgi apparatus are present. In parallel, chondrones are found in which cellular contact functions via a cilium. Time-dependent glycogen occurs in these cells too. Cells having almost the same synthesis time course of the glycogen join up to form "functional units", which are particularly involved in the biomechanic cartilage behavior in the radiar cell zone.

Familial amyotrophic lateral sclerosis with a novel Leu126Ser mutation in the copper/zinc superoxide dismutase gene showing mild clinical features and lewy body-like hyaline inclusions

BACKGROUND

Mutations in the SOD1 gene are responsible for approximately 25% of all familial amyotrophic lateral sclerosis (ALS) cases. However, the correlation between the clinical and pathological features and the various SOD1 gene mutations has not been well characterized.

OBJECTIVES

To screen the SOD1 gene in search of potential mutations and to obtain clinical and pathological data for 2 Japanese families with ALS.

DESIGN

Clinical histories and neurological findings, gross and microscopic pathological features, and DNA analysis of the SOD1 gene.

RESULTS

The 2 families with ALS showed a novel missense mutation in the SOD1 gene, which was heterozygous for point mutation TTG to TCG, causing substitution of leucine for serine at codon 126 (Leu126Ser) in exon 5. Clinically, patients showed slower disease progression and lack of upper motor neuron signs. Neuropathologically, the autopsied patient showed the form of familial ALS with posterior column involvement, and the pontocerebellar tract and the dentate nuclei of the cerebellum were also involved. Furthermore, abundant Lewy body-like hyaline inclusions were observed in the affected motor and nonmotor neurons.

CONCLUSIONS

Familial ALS with a novel Leu126Ser mutation in the SOD1 gene showed mild clinical features and lack of upper motor neuron signs. We believe that Leu126Ser might be associated with the clinical features and that the mutation site in the SOD1 gene and disease duration might be associated with the formation of Lewy body-like hyaline inclusions.

Recruitment of nonexpanded polyglutamine proteins to intranuclear aggregates in neuronal intranuclear hyaline inclusion disease

Recruitment of polyglutamine-containing proteins into nuclear inclusions (NIs) was investigated in neuronal intranuclear hyaline inclusion disease (NIHID). Some polyglutamine-containing proteins, ataxin-2, ataxin-3, and TATA box binding protein (TBP), as well as unidentified proteins with expanded polyglutamine tracts were recruited into NIs with different frequencies. Ataxin-3 was incorporated into most of the NIs and disappeared from its normal cytoplasmic localization, whereas only a small fraction of NIs contained ataxin-2 and TBP. The consistent presence of ataxin-3 in NIs could reflect a biological feature of wild-type ataxin-3, which is translocated into the nucleus under pathological conditions and participates in the formation of aggregates. Ataxin-2 also accumulated in the nucleus, but was not necessarily incorporated into NIs, suggesting that transport of these cytoplasmic proteins into the nucleus and their recruitment into NIs are not wholly explained by an interaction with a polyglutamine stretch and must be regulated in part by other mechanisms. The prevalence of ubiquitin-immunopositive NIs was inversely correlated to neuronal loss in all cases examined. This correlation could be explained if NI formation is a protective mechanism involving the ubiquitin-proteasome pathway. This hypothesis is supported by the finding that the polyglutamine epitope in the center of NIs was surrounded by ubiquitin.

Ultrastructure of early mineral deposition during hyaline layer formation in rat molars

There is no consensus on whether the first mineralized layer, the hyaline layer, that is juxtaposed to root dentine is a variety of dentine or cementum or even a tissue of epithelial origin. Some suggest that there is no intermediate tissue between the acellular extrinsic fibre cementum (AEFC) and the root dentine. Here, to study hyaline layer formation and mineralization we examined by transmission electron microscopy the early stages of root development in upper molars from 10 to 13 day old Wistar rats. In addition to conventionally processed material, undemineralized and unstained sections were examined, which showed the deposition of fine mineral crystals in contact with the mineralized surface of root dentine. Early mineralization of the hyaline layer occurred in the region of the inner basement membrane, which persisted between the inner cellular layer of Hertwig's epithelial root sheath and the outer mineralized root dentine. When the root sheath began its fragment, collagen fibrils from the developing periodontal ligament began to insert into the mineralising hyaline layer, which was 0.5-0.8 micron wide. As the fragmentation of the root sheath HERS increased, more collagen fibrils appeared intermingled with the mineralising hyaline layer. In more advanced stages, when the hyaline layer had become fully mineralized and the formation of the AEFC began, the hyaline layer could no longer be identified. Thus, the hyaline layer is clearly discernible at early stages of periodontal development. Subsequently, it is masked by intermingling of cementum and dentine and therefore it is not possible to detect it in the formed roots of rat molars.

Hyalinising spindle cell tumour with giant rosettes: report of a case with unusual features including original histological and ultrastructural observations

Hyalinising spindle cell tumour with giant rosettes (HSCTGR) is an uncommon, recently described low-grade sarcoma which shares many histological features with low-grade fibromyxoid sarcoma (LGFMS). We report a case of HSCTGR occurring in the deep soft tissues of the thigh of a 46-year-old woman, that presented as a slowly growing, painless mass. Microscopically the tumour was composed of spindled stromal cells amongst which were scattered so-called collagen rosettes. The distinctive feature of this case was the previously unreported finding of lymphoid cells of T-cell phenotype admixed with fibrohistioctyic cells in the cellular cuff surrounding the collagenous core of the rosettes. The case was further unusual in that it included focal areas of increased cellularity with a mitotic count of up to three per 10 high-power fields. While the latter feature has been associated with increased recurrences and metastases in LGFMS, it is not known whether the significance is similar in HSCTGR. The spindled stromal cells showed ultrastructural features of poorly differentiated fibroblasts, while those at the edges of the rosettes showed features of altered fibroblasts, some with a fibrohistiocytic appearance. These findings support the interpretation that HSCTGR forms part of the spectrum of sarcomas showing fibroblastic differentiation.

Middle ear effusions and structure of the tympanic membrane

OBJECTIVE

To study the effect of various middle ear effusions on the structure of the lamina propria of the tympanic membrane.

METHODS

Sterile and infective middle ear effusions were induced by obstruction of the eustachian tube in specific pathogen-free (SPF) rats and in rats with upper airway infections (URI), respectively. The condition of the tympanic membrane was monitored at regular intervals. After varying survival times, the animals were killed and the tympanic membranes processed for light and electron microscopy.

RESULTS

Sterile effusions always resulted in tympanosclerotic lesions. These lesions did not develop in the presence of primary-infected effusions. These effusions had a severe destructive effect on the lamina propria, followed by fibrosis. Generally, secondary infection did not markedly affect preexisting tympanosclerotic lesions. Moreover, calcification disappeared when re-aeration of the middle ear occurred, but the abnormal collagen depositions persisted.

CONCLUSIONS

Both sterile and infective effusions result in comprehensive irreversible changes in the lamina propria of the pars tensa. The development of tympanosclerosis is confined to sterile effusions. Mechanical injury and compromised vascularization of the lamina propria are likely to be important etiological factors in the development of tympanosclerosis.

Immunohistochemical localization of tenascin, fibronectin, and type III collagen in human dental pulp

The distribution of tenascin (TN), fibronectin (FN), and type III collagen (col III) in the extracellular matrix of the connective tissue of normal, inflamed, and hyalinized human dental pulp was studied by immunohistochemical staining with monoclonal antibodies against these molecules. TN, FN, and col III were present in all normal tissues studied. In areas of hyalinization only col III was observed. None of the molecules studied were seen in areas of inflammatory exudate. Strong staining for TN and FN was found in the periphery of all specimens analyzed next to the odontoblastic layer. We therefore conclude that TN, FN, and col III are present in the extracellular matrix of normal human dental pulp. TN, FN, and col III distribution in inflammatory and degenerative processes is different from that observed in normal human dental pulp.

"Thanatosomes": a unifying morphogenetic concept for tumor hyaline globules related to apoptosis

Hyaline globules (HG) have been observed in a large variety of unrelated categories of tumors and benign tissues. Different explanations for their formation have been proposed, varying according to tumor type and anatomic location. We have studied 80 tumor cases containing HG, by light microscopy, electron microscopy, immunohistochemical stains for various plasma proteins, and in situ DNA-end labeling for apoptosis. On light microscopy, HG were invariably related to areas of increased apoptosis and often contained apoptotic nuclear fragments. The HG stained as expected, with variable intensity with acidic stains. Most cells containing HG stained with immunohistochemical stains for all plasma proteins examined (alpha-1-antitrypsin, ferritin, C3, kappa and lambda light chains, and IgG), indicating an increased plasma membrane permeability. A morphologic change associated with the increased permeability was cytoplasmic blebbing. In the HG themselves, immunohistochemical stains for the plasma proteins were either diffusely positive or stained only the periphery of the larger HG. Double stains for apoptosis and plasma proteins confirmed the increased plasma membrane permeability to proteins of apoptotic cells in general and cells containing HG in particular. Free hyaline globules were often linked to the extracellular matrix by fibrin fibrils. Ultrastructurally, the HG appeared as phagosomes/secondary lysosomes or areas of cytoplasmic condensation surrounded by rough endoplasmic reticulum whorls. These were always associated with intense cytoplasmic blebbing. We conclude that HG reflect stages of cell injury, which in most instances relate to apoptotic cell death. They are specifically associated with the cytoplasmic blebbing and condensation typically seen in this form of cell death. These phenomena are accompanied by plasma protein influx (insudated plasma) and formation of distinct intracellular "hyalinized" cellular fragments. With cell fragmentation, the HG become extracellular and are likely to be ultimately disposed of by a process of "remodeling" and incorporation into the extracellular matrix, followed by collagenization. The latter process partly occurs by the initial linking of all components (HG, collagen fibers, cellular fragments, etc.) by a network of fibrin. The process of formation of HG follows a stereotypical pathway independent of cell type. Because it results mostly from apoptotic cell death, it is more pronounced in rapidly growing tumors or posttreatment. We propose the term thanatosomes for the entire spectrum of HG to emphasize their relationship to cell death. HUM PATHOL 31:1455-1465.

Age changes in the cells of the intra-articular disc of the temporomandibular joints of rats and marmosets

Cells in the intra-articular disc of the temporomandibular joint were studied ultrastructurally at three different ages to investigate any age changes. Rats aged 2, 15.5 months, and 2.5 years, and marmosets aged 21 months, 7 years, and between 10.5 and 14 years were studied. In the first two age groups of the rat and the first of the marmoset, the cells were generally rounded and had moderate amounts of rough endoplasmic reticulum and other organelles associated with protein synthesis and secretion. Many cells had conspicuous amounts of microfilamentous material and cell membranes were closely applied to the collagen fibrils of the extracellular matrix. Occasionally, a narrow, irregular space containing microfilamentous material lay adjacent to the cell membrane. In the 2.5-year-old rats and the two older age groups of marmosets, cells with chondrocyte-like morphology were present. These cells were surrounded by a conspicuous pericellular matrix devoid of collagen fibrils and composed of microfilamentous material embedded in an amorphous ground substance. They resembled cells described in fibrocartilage from other sites, but differed from chondrocytes in hyaline cartilage by lacking a pericellular capsule. Thus, rats and marmosets both show cellular age changes in the intra-articular disc of the mandibular joint, which can be considered as changing from fibrous to fibrocartilaginous with age, a condition similar to that reported in humans.

Gene-related protein surplus myopathies

Numerous muscular dystrophies, such as dystrophinopathies, sarcoglycanopathies, and emerino- and laminopathies, are marked by the absence or reduction of mutant transsarcolemmal or nuclear proteins. In addition to these recently identified minus-proteinopathies, there are a growing number of plus-proteinopathies among neuromuscular disorders marked by a surplus or excess of endogenous proteins within muscle fibers of different, i.e., nontranssarcolemmal and nonnuclear types. These proteins are often filamentous; for example, desmin and actin accrue in respective desmin-related myopathies, among which are entities marked by mutant desmin, true desminopathies, and actinopathy, the latter often seen as a subgroup in nemaline myopathies. Desmin-related myopathies consist largely of those marked by desmin-containing inclusions and those characterized by desmin-containing granulofilamentous material. When mutations in the desmin gene can be identified, the mutant desmin is thought to form the major myopathological lesion. Together with desmin, other proteins often accumulate. The spectrum of these proteins is quite diverse and encompasses such proteins as dystrophin, nestin, vimentin, alphaB-crystallin, ubiquitin, amyloid precursor protein, and beta-amyloid epitopes, as well as gelsolin and alpha(1)-antichymotrypsin. Among these associated proteins, one, alphaB-crystallin, has been found mutant in one large family, justifying the term alphaB-crystallinopathy as a separate condition among the desmin-related myopathies. Other proteins accruing with desmin have not yet been identified as mutant in desmin-related myopathies. Mutations in the desmin gene entail missense mutations and small deletions. The formation of mutant actin may lead to aggregates of actin filaments which may or may not be associated with formation of sarcoplasmic and/or intranuclear nemaline bodies. A considerable number of missense mutations in the sarcomeric actin gene ACTA1 have been discovered in patients with nemaline myopathy and also in a few patients without myopathological evidence of nemaline bodies in biopsied skeletal muscle fibres. Apart from alphaB-crystallin, no other proteins coaggregating with actin in actin filament aggregates of actinopathy or the actin mutation type of nemaline myopathy have so far been identified. Two further candidates for protein surplus myopathies are hyaline body myopathy, which is marked by accumulation of granular nonfilamentous material within muscle fibers that is rich in myosin and adenosine triphosphatase activities, and hereditary inclusion body myopathies, which are marked by accumulation of tubulofilaments similar to the helical filaments of Alzheimer neurofibrillary tangles. These tubulofilaments consist of diverse proteins as well, though no mutant protein has yet been discovered. So far, no genes responsible for familial hyaline body and hereditary inclusion body myopathies have been identified. The discovery of mutant proteins, desmin, alphaB-crystallin, and actin, as components of surplus or excess proteins accumulating in muscle fibers in certain neuromuscular conditions is responsible for the recent emergence of this new concept of gene-related protein surplus myopathies.

Late onset hyalinosis cutis et mucosae

Two cases of non-familial, late onset (50 and 62-years-old) hyalinosis cutis et mucosae were studied and compared with classical early onset cases. Late onset cases showed essentially the same histological and ultrastructural features described for early onset cases. The late onset variety should be distinguished from other diseases; they resemble systemic amyloidosis and sometimes the adult form of colloid milium.

Intracytoplasmic hyaline inclusions in the hippocampal neurons of two cattle

This report deals with the large intracytoplasmic hyaline inclusions observed in hippocampal large pyramidal cells of two Holstein-Friesian cattle. These inclusions were round to elongated polyhedral in shape with consistently homogeneous glassy appearance; they varied in size and were positive for the periodic acid-Schiff reaction and silver impregnation. Electron microscopic examination revealed that the inclusions consisted of granular materials showing moderate electron density and were bounded by a unit membrane. On the external surface of the unit membrane, there were direct connections to cellular organelles, including ribosome, rough endoplasmic reticulum, and mitochondria. These findings suggest that the inclusions might be derived from neuronal endoplasmic reticulum.