False-positive staining of thyroglobulin distinguished from mixed medullary and follicular thyroid carcinoma by duplex in situ hybridization

Medullary thyroid carcinoma (MTC) may mimic mixed medullary and follicular thyroid carcinoma (MMFTC). MTC originates from para-follicular cells, while MMFTC is an uncommon tumor characterized by coexistence of follicular and para-follicular cell-derived tumor populations. A 35-year-old woman was diagnosed with MTC but showed a hot nodule in thyroid scintigraphy. The tumor included diffusely-spread follicular lesions within it, which were immunostained with thyroglobulin and calcitonin. Immunofluorescence showed the presence of several tumor cells that were double-stained with thyroglobulin and calcitonin. To clarify whether or not the tumor was MMFTC, we used duplex in situ hybridization (ISH). Thyroglobulin and calcitonin-related polypeptide alpha mRNA were not expressed together in a single cell, so we suspected false-positive staining of tumor cells with thyroglobulin. To make comparisons with other follicular lesions in MTC, we searched our hospital database. Five cases within a ten-year period had been pathologically diagnosed as MTC. All had follicular lesions in the tumor, but unlike the other case, they were peripherally localized. Dual differentiation into follicular or para-follicular tumor cells was not indicated by either immunofluorescence or duplex ISH. Compared with the case suspected to be MMFTC, there was only mild invasion of tumor cells into the follicular epithelium. The extent of follicular lesions and invasiveness of tumor cells may be associated with pseudo-staining of thyroglobulin in MTC. Duplex ISH can distinguish MTC that are stained with thyroglobulin from MMFTC.

Combined papillary and mucoepidermoid carcinoma of the thyroid gland: a possible collision tumor diagnosed on fine-needle cytology. Report of a case with immunocytochemical and molecular correlations

Fine-needle cytology (FNC) is frequently used to diagnose thyroid nodules discovered by palpation or imaging studies. Molecular tests on FNC material may increase its diagnostic accuracy. We report a case of a classic papillary thyroid carcinoma combined with a mucoepidermoid carcinoma correctly identified on FNC. The papillary component had a classic immunophenotype (CK19+, TTF1+), while the mucoepidermoid one was only focally CK19+. Point mutations (BRAF and RAS) and rearrangements (RET/PTC) of the papillary component have been also investigated on FNC samples, with resulting concurrent rearrangements of RET/PTC1 and RET/PTC3, but no point mutations. The histogenesis of combined papillary and mucoepidermoid carcinoma of the thyroid still remains partly unsettled, and further genomic studies are needed to shed some more light on this peculiar neoplasm.

[Clinicopathologic features of combined hepatic carcinoma]

OBJECTIVE

To investigate clinicopathological features of combined hepatocellular-cholangiocarcinoma (C-HCC-CC) with neuroendocrine carcinoma (NEC) differentiation and to review the literature.

METHODS

The clinical data, histological manifestations and immunohistochemical staining results of two cases of C-HCC-CC were analyzed along with a review of the current literature.

RESULTS

Both patients were male with an average age of 57.5 years. Both patients were positive for hepatitis B virus antigen. The tumors of both cases demonstrated the following 3 unequivocal mixed elements: (1) polygonal epithelial tumor cells growing in nests or trabeculae with positive staining for Hepatocyte and AFP, diagnostic of hepatocellular carcinoma (HCC). Cytoplasmic bile production was present in the tumor cells in one case; (2) elliptic or short spindle-shape small blue tumor cells growing in nests or organoid pattern with Syn/CgA/CD56 positivity confirming the presence of neuroendocrine carcinoma (NEC) component; (3) oval tumor cells growing in nests or glandular forms with positivity of CK19 and CK7 confirming differentiation of cholangiocarcinoma (CC). In both cases, the tumors contained at least 20% of each of HCC, NEC and CC components.

CONCLUSION

C-HCC-CC with NEC is a rare form of primary malignancy of the liver with a poor prognosis.

Mixed Epithelial and Stromal Tumor of the Kidney: Preliminary Immunohistochemical and Electron Microscopic Studies of the Epithelial Component

Mixed epithelial and stromal tumor of the kidney is a rare biphasic tumor composed of cysts and tubules embedded in the spindle cell stroma. Although the histogenesis of this tumor is unknown, it has been proposed that both components of the tumor, i.e., stromal and epithelial, are neoplastic. The authors report preliminary immunohistochemical and electron microscopic studies of the epithelial component from one case of a typical, benign, mixed epithelial, and stromal tumor of the kidney. In this study, some tubules showed positivity for proximal, while others showed positivity for distal, nephron immunomarkers. By electron microscopy, some tubules had features of proximal tubular epithelium, while other tubules had features of the loop of Henle (thin segments). The authors believe that in a benign tumor such morphologic heterogeneity is inconsistent with neoplastic proliferation. Therefore, they postulate that in mixed epithelial and stromal tumor of the kidney the tubules are entrapped rather than neoplastic. Additional studies are needed to address this issue and electron microscopy should play a significant role in this process.

An unusual mixed tumor of the pancreas: sonographic and MDCT features

CONTEXT

Mixed tumors of the pancreas are exceedingly rare.

CASE REPORT

We herein report on a 54-year-old female who presented with an enlarging cystic lesion in the head of the pancreas. Right upper quadrant ultrasound and multidetector-row CT scan showed a well-defined unilocular cystic tumor located in the head of the pancreas and surrounded, in part, by a hypervascular solid mass.

CONCLUSION

Although mixed exocrine/endocrine pancreatic tumors have been described previously, to the best of our knowledge, this is the first case of a pancreatic mixed intraductal papillary mucinous neoplasm/endocrine tumor with illustration of its ultrasound and CT features. Moreover, the importance of preoperative analysis of imaging features in the assessment of pancreatic neoplasms is discussed.

A conditional mouse model for malignant mesothelioma

Malignant mesothelioma is a devastating disease that has been associated with loss of Neurofibromatosis type 2 (NF2) and genetic lesions affecting RB and P53 pathways. We introduced similar lesions in the mesothelial lining of the thoracic cavity of mice. Mesothelioma developed at high incidence in Nf2;Ink4a/Arf and Nf2;p53 conditional knockout mice with median survival times of approximately 30 and 20 weeks, respectively. Murine mesothelioma closely mimicked human malignant mesothelioma. Conditional Nf2;Ink4a/Arf mice showed increased pleural invasion compared to conditional Nf2;p53 mice. Interestingly, upon Ink4a loss in the latter mice median survival was significantly reduced and all tumors were highly invasive, suggesting that Ink4a loss substantially contributes to the poor clinical outcome of malignant mesothelioma.

Adenoid cystic/basal cell carcinoma of the prostate strongly expresses HER-2/neu

Adenoid cystic/basal cell carcinoma (ACBCC) is a rare neoplasm in the prostate. Definitive treatment is warranted, as among 19 patients previously reported by us, 5 had extraprostatic extension and 4 were metastatic. The HER-2/neu (c-erbB-2) gene has been reportedly overexpressed in adenoid cystic carcinomas in other organs, but its status in prostatic ACBCC was uncertain. Immunohistochemical staining and in situ hybridisation were carried out in 13 patients with ACBCC (11 from transurethral resection, 2 prostatectomy). One patient had metastasis to the lung. Citrate buffer and steam heat were used for antigen retrieval. Ten acinar adenocarcinomas of varying grades were also immunostained as controls. Protein and mRNA expression were 2+ to 3+ (of 3+) in all patients with ACBCC, compared to a breast cancer control with strong reactivity, whereas protein expression was noted in only one acinar carcinoma and mRNA expression was absent in all acinar carcinomas. Benign acini expressed HER-2/neu only in the basal layer. The finding of strong, consistent HER-2/neu expression in ACBCC suggests that treatment with Herceptin (trastuzumab) may be effective in patients with this rare tumour.

Transformed dermatofibrosarcoma protuberans: real time polymerase chain reaction detection of COL1A1-PDGFB fusion transcripts in sarcomatous areas

BACKGROUND

Recent cytogenetic studies have shown that reciprocal translocation t (17;22)(q22;q13) and a supernumerary ring chromosome derived from the translocation r(17;22) are highly characteristic of dermatofibrosarcoma protuberans (DFSP). The chromosomal rearrangements fuse the collagen type Ialpha1 (COL1A1) and the platelet-derived growth factor B-chain (PDGFB) genes. The COL1A1-PDGFB fusion transcript has been shown not only in conventional DFSP but also in a small series of DFSP with fibrosarcomatons areas (DFSP-FS) using reverse transcriptase-based conventional polymerase chain reaction. Nothing is known about the status of the COL1A1-PDGFB chimaeric gene in the pleomorphic areas of DFSP-PleoSarc (formerly known as DFSP-malignant fibrous sarcoma).

AIMS

To show the COL1A1-PDGFB fusion transcript in transformed malignant fibrous histiocytoma.

METHOD

A real-time polymerase chain reaction assay for the COL1A1-PDGFB fusion transcript in a series of DFSP containing sarcoma was conducted to determine whether the chimaeric gene could be identified in both components of DFSP-FS and DFSP-PleoSarc. Eight cases were analysed.

RESULTS

In seven cases, transcriptable RNA was detected, and in these cases, translocations were found between COL1A1 and PDGFB genes involving exons 27, 32, 34, 40 and 47 of the COL1A1 gene and exon 2 of the PDGFB gene.

CONCLUSIONS

From a diagnostic aspect, this assay can be particularly useful in confirming the diagnosis of sarcomatous DFSP. On the other hand, the COL1A1-PDGFB fusion gene was shown in three cases of DFSP containing pleomorphic sarcoma, which supports the theory of the common histogenesis.

Lipomatous mixed tumor with follicular differentiation of the skin

A very rare case of cutaneous mixed tumor with numerous adipose tissue and hair follicular structures in a 67-year-old Japanese male was reported. A well-circumscribed tumor was in the subcutaneous tissue of the cheek and far from the parotid gland. Histologically, the tumor consisted of an admixture of the adipose tissue, fibromyxoid tissue with spindle cells, and branching tubular structures. Outer layers of ductal epithelial cells and single spindle cells were often in a transition, likely as typical mixed tumor. Branching ducts connected with keratinous cysts, strands of trichoblastic basophilic cells and clear cell nests. There was a gradual transition, between small-sized adipocytes and vacuolated spindle cells. No chondroid stroma was seen. To our knowledge, this tumor is the first case of a lipomatous mixed tumor with hair follicular differentiation. The case indicates an additional wide spectrum of histologic appearances of cutaneous mixed tumor.

Salivary Gland-Type Tumors With Myoepithelial Differentiation Arising in Pulmonary Hamartoma

Reported is a hitherto unrecognized association of pulmonary hamartomas with salivary gland-type tumors showing myoepithelial differentiation, namely, a case of myoepithelioma arising in a otherwise classic hamartoma with cartilage predominance, and a case of malignant mixed tumor arising in a predominantly fibrous hamartoma resembling müllerian adenofibroma. The tumors occurred in middle-aged female patients of 35 and 44 years, respectively, and presented as 7 cm (treated with lobectomy) and 13 cm (treated with pneumonectomy) masses of the right upper lobe showing a short clinical history of cough, dyspnea, and wheezing. Both lesions did not present regional lymph node metastases after mediastinal lymphadenectomy. The myoepithelioma patient was well with no signs of recurrent disease at 6-month clinical control, but she was then lost to follow-up; the malignant mixed tumor patient is alive and well after 6 months since operation. Both tumors presented with morphologic and immunohistochemical features of myoepithelial cells, and we interpret them as being derived from a myoepithelial-like stromal cell population found within the hamartomatous areas, which is also consistently detected in classic pulmonary hamartoma. The lack of individual cell necrosis, mitotic activity, cell atypia, and pulmonary parenchyma infiltration supported a diagnosis of benign or unproven malignant potential tumor for the myoepithelioma, whereas the reverse held true for the other tumor in which the diagnosis of malignant mixed tumor of the lung was rendered. Their main importance of recognizing this association lies in separating these tumors histologically from other monophasic or biphasic tumors, either primary or secondary, such as pulmonary sarcomatoid carcinomas or true sarcomas, and metastatic salivary gland tumors, spindle cell carcinomas, melanomas, and soft tissue and visceral sarcomas.

Mixed osteoclastic/pleomorphic giant cell tumor of the pancreas: a case report

BACKGROUND

Mixed giant cell tumor (MGCT) of the pancreas is a rare malignant neoplasm. The tumor contains pleomorphic giant cells (PGC), pleomorphic mononuclear cells (PMC) and osteoclastic giant cells (OGC). We describe the first fine needle aspiration biopsy (FNAB) diagnosis of this tumor.

CASE

A 76-year-old woman was discovered (on imaging studies) to have an apparently inoperable mass in the head of the pancreas. Computed tomography-guided FNAB showed a malignant neoplasm with features of an MGCT. PGC/PMC, OGC and spindle cells were present. The PGC/PMC expressed epithelial antigens, pancytokeratin, CAM 5.2, AE1/AE3 and epithelial membrane antigen (EMA). The spindle cells focally stained for EMA. OGC were negative for the epithelial antigens. OGC, PGC/PMC and the spindle cells were positive for the mesenchymal marker vimentin.

CONCLUSION

FNAB was instrumental in making the diagnosis of a rare pancreatic tumor, MGCT. Immunocytochemistry was helpful in making a definitive diagnosis and suggested that MGCT is a carcinosarcoma like neoplasm. The morphology and immunocytochemical profile raise the possibility that osteoclastic giant cell tumor and pleomorphic giant cell tumor may be different morphologic and biologic expressions of the same tumor.

Bone morphogenetic protein-mediated type II collagen expression in pilomatricoma and cutaneous mixed tumor

BACKGROUND

We have previously reported that type II collagen deposition in overlying dermo-epidermal junction (DEJ) of pilomatricoma is mediated by bone morphogenetic protein 2/4 (BMP 2/4) expressed by shadow cells (SCs) of pilomatricoma.

OBJECTIVE

This time, we studied the expression of type II collagen and BMP in a large number of cases of pilomatricoma and extended our study to cutaneous mixed tumor (CMT).

RESULTS

We found type II collagen deposition in the overlying DEJ (16 of 50 cases) and in the SCs (19/50) of pilomatricoma. The number of case of type II collagen deposition in DEJ (DEJ(+)) and in SCs (SC(+)) of pilomatricoma correlated to the chronological stage of pilomatricoma. We also found type II collagen deposition in overlying DEJ (two of 11) and in the stromal chondroid tissue (four of 11) of CMT. BMP 2 was expressed in most cases of pilomatricoma (37/50) and CMT (seven of 11).

CONCLUSIONS

The expression of type II collagen in pilomatricoma is dependent upon the chronological stage of pilomatricoma. Type II collagen expression in the overlying DEJ and chondroid matrix in CMT may be induced by BMP via the same mechanism as in pilomatricoma.

Mixed micropapillary and trophoblastic carcinoma of bladder: report of a first case with new immunohistochemical evidence of urothelial origin

The micropapillary variant of urothelial carcinoma has a reported incidence of 0.7%. Trophoblastic urinary carcinoma is very rare, with roughly 30 cases reported during the last century. This is the first report of mixed micropapillary and trophoblastic bladder carcinoma. A 45-year-old man presented with gross hematuria. His tumor contained choriocarcinomatoid areas with syncytiotrophoblasts, classic micropapillary carcinoma, conventional high-grade urothelial carcinoma, and flat carcinoma in situ. He underwent radical surgery; tumor stage was T4N2M0. Despite postoperative combination chemotherapy, he developed pulmonary and retroperitoneal metastases and died 20 months after presentation. The tumor was immunopositive for human chorionic gonadotropin and human placental lactogen in trophoblast and for cytokeratin 20 and high-molecular-weight cytokeratin in all tumor components. Because high-molecular-weight cytokeratin is expressed by urothelium but is rarely found in placental trophoblast or germ-cell choriocarcinoma, its presence in trophoblastic bladder carcinoma is new evidence that the latter is a transformed neoplasm of urothelial origin.

Combined small cell carcinoma and clear cell carcinoma of the gallbladder: report of a case and review of the literature

We report a case of an incidental combined carcinoma of the gallbladder in a 66-year-old woman who underwent cholecistectomy for gallstones. The neoplasm was mainly constituted by a clear cell component and a small cell, chromogranin-positive one; it also showed some areas of conventional adenocarcinoma and foci of vascular invasion. The patient died after 3 years following treatment with combination chemotherapy. The histologic and immunohistochemical profile of the lesion is described, together with a brief review of the pertinent bibliography.

Mixed ductal-pancreatic polypeptide-cell carcinoma of the pancreas

AIMS

Mixed ductal-endocrine carcinomas of the pancreas are rare tumours with 10 cases reported in the English literature. We report the first case with a polypeptide-cell component.

METHODS AND RESULTS

: The tumour was fortuitously discovered in a 72-year-old woman during the exploration of an endometrial adenocarcinoma. It measured 100 mm and was located in the tail of the pancreas. On microscopic examination two intermingled endocrine and exocrine components were present. The endocrine component consisted of trabeculae and solid nests composed of cells immunoreactive for chromogranin A, synaptophysin and pancreatic polypeptide, but negative for p53 and Bcl-2 proteins. The exocrine component was composed of tubules lined by atypical cylindrical cells immunoreactive for CK19, CEA, p53 and Bcl-2. The stroma of the endocrine component contained amyloid deposits.

CONCLUSION

Mixed ductal-endocrine carcinomas of the pancreas are often described in middle-aged patients. The tumours are usually large and located in the head of the pancreas. An endocrine syndrome is rare and the prognosis is often unfavourable. We report the first case of mixed endocrine-exocrine carcinoma of the pancreas with a pancreatic polypeptide-cell component. The histogenesis of mixed carcinoma of the pancreas is still uncertain but the over-expression of p53 and Bcl-2 could play a major role in the neoplastic progression of the ductal component.

Mixed pituitary adenoma-gangliocytoma in a female albino rat

A mixed intrasellar pituitary adenoma-gangliocytoma was found incidentally in an aged female Sprague-Dawley-derived rat. The animal was killed at the end of a 104-week carcinogenicity study. At necropsy, the pituitary fossa was occupied by a large, hemorrhagic nodule compressing and displacing the base of the brain. The lesion consisted of large areas of a prolactin-secreting adenoma surrounding a central island of gangliocytoma. In the latter, ganglion-like cells of varying size exhibited, occasionally, beta-tubulin and neurofilament protein immunoreactivity in their perikarya, while their cell processes expressed intense neurofilament immunoreactivity. Accompanying satellite cells in the neuropil immunostained for glial acidic and S-100 proteins. To the best of our knowledge, the presence of mixed pituitary adenoma-gangliocytoma has not been previously reported in rats.

Mixed medullary-follicular carcinoma and papillary carcinoma of the same thyroid

We report a rare case of mixed medullary-follicular carcinoma and papillary carcinoma of the same thyroid. A 27-year-old Chinese female complained of a single thyroid nodule for 2-3 months. Needle aspiration revealed suspicious papillary carcinoma and thyroidectomy performed later showed mixed medullary-follicular carcinoma and papillary carcinoma of the same thyroid which was extremely rare. Whether neoplastic transformation is due to tumorigenic stimulus or just due to the collision phenomenon is still controversial for its etiology.

[The expression of proliferating cell nuclear antigen and p53 protein in salivary gland tumours]

The expressions and distributions of PCNA and p53 protein were studied with anti-PCNA and anti-p53 protein MoAbs, using immunohistochemical staining method in salivary gland tumour. The relationship between PCNA and p53 protein was also studied. Results indicated: Malignant mixed tumour (MmT) had a higher proliferating index (PI) of PCNA. The PI could be used as one of adjuvant diagnostic criteria; and as an important parameter for grading mucoepidermoid carcinoma (MEC); The positive expression of p53 might be a good tumour marker for MmT; Tumour tissues with positive expression of p53 had been shown higher PI of PCNA, however there was no significance difference in our group; It remained to be studied later.

Benign and malignant salivary gland-type mixed tumors of the lung. Clinicopathologic and immunohistochemical study of eight cases

BACKGROUND

Primary lung tumors showing features of salivary gland-type neoplasms are extremely rare.

METHODS

Eight patients with primary lung neoplasms showing light microscopic and immunohistochemical features of salivary gland-type mixed tumors were studied.

RESULTS

The patients were six women and two men, ages 35-69 years (mean, 52.5 years). The tumors ranged from 2 to 16 cm in greatest diameter. In two patients the lesions presented as polypoid endobronchial lesions obstructing the lumen; in another two patients the lesions were found in close proximity or in continuity with a bronchus; in three patients, the lesions presented as peripheral parenchymatous nodules unrelated to a bronchus; and in one patient, the relationship to the bronchus could not be determined. Histologically, the lesions were biphasic, showing admixtures in varying proportions of epithelial elements containing a predominant myoepithelial cell population with a stromal component containing an abundant myxoid or focally chondroid matrix. Immunohistochemical studies showed strong positivity of the cells in the epithelial component with low molecular weight keratins (CAM 5.2), and to a lesser extent with broad spectrum keratin, actin, and vimentin antibodies. The cells also showed variable reactivity in the epithelial and nonepithelial elements with S-100 protein and glial fibrillary acidic protein. Six tumors were grossly and histologically benign; in two patients, the tumors were larger, locally invasive, and showed more atypical histologic features. All patients were treated with surgical excision. On follow-up, of the six patients with histologically benign-appearing tumors, one was alive and well 6 years after surgery; another died 4 years after surgery of a second unrelated malignancy; one died during the immediate postoperative period of myocardial infarction; and three have been lost to follow-up. In the two patients with histologically atypical lesions, the tumors recurred and metastasized after 2 and 3 years, respectively, with one of them leading to death caused by widespread metastases and superior vena cava syndrome.

CONCLUSIONS

Review of the literature and the findings in the current series indicate that salivary gland-type mixed tumors of the lung may present with a spectrum of histologic features and clinical behavior, ranging from benign to frankly malignant, similar to that observed for their salivary gland counterparts. Size of the lesion at the time of presentation, extent of local infiltration, and degree of mitotic activity appear to be the most reliable prognostic features of these tumors.

Mixed pituitary tumours--effects of bromocriptine treatment: Parlodel MR and Parlodel LAR

Majority of pituitary tumours secrete one of the named hormones: PRL, GH, ACTH, proopiomelanocortine, alpha and beta subunit of TSH, LH, and FSH. Some of those tumours secrete two or more hormones. The aim of this study was to determine the effect of bromocriptine (Parlodel MR and LAR) upon secretion of hormones and tumour size in 10 patients with mixed pituitary tumours. In all patients pituitary and peripheral hormones, CT scan and visual fields were examined before and after treatment with bromocriptine: Parlodel MR and LAR. Bromocriptine treatment decreased PRL secretion in all 10 patients; GH--in all 6 in whom it was increased; TSH--in 2, FSH--in 2 and alpha-subunit in all 6 in whom they were increased. In 5 patients treatment resulted in shrinkage of the tumour mass by 20 to 35%. In all examined subjects clinical improvement was achieved. Our results demonstrate that bromocriptine (Parlodel MR and LAR) is very effective and well tolerated in the treatment of patients with mixed pituitary tumours particularly those with hyperprolactinemia.