TLE1 Expression in Malignant Rhabdoid Tumor and Atypical Teratoid/Rhabdoid Tumor.

Malignant rhabdoid tumors (MRT; atypical teratoid/rhabdoid tumor [ATRT] in the central nervous system) are aggressive tumors in infants and children which can overlap with other sarcomas, such as synovial sarcoma (SS). The gold standard for SS diagnosis is characterization of the t(X;18) chromosomal translocation. However, stratification of cases for molecular analysis is not always straightforward or feasible. Recent literature suggests transducer-like enhancer of split 1 (TLE1) protein expression may distinguish SS from certain histologic mimics; however, this has not been investigated in MRT and ATRT. We stained whole-tissue sections of 18 archived cases of MRT and ATRT with TLE1. Nuclear expression was scored using a 4-tiered (0, 1+, 2+, and 3+) scale describing staining intensity, extent, or combination of both. The majority of MRT and ATRT cases showed some TLE1 immunoreactivity (n = 16; 89% for ≥1 + staining); 14 (78%) of total cases showed ≥2 + positivity using any of the 3 scoring systems. Over half (n = 10; 56%) of cases showed ≥2 + staining; 4 (22%) cases showed 3 + strong and diffuse TLE1 staining measured by all scoring systems in agreement. Although still of potential use, we urge caution in the interpretation of TLE1 when the differential diagnosis includes both SS and MRT or ATRT.

Mixed endometrial stromal and smooth muscle tumor of the uterus in a postmenopausal woman: morphologic and immunohistochemical features.

Mixed endometrial stromal and smooth muscle tumor of the uterus is a rare occurrence, and it is truly challenging to diagnose or dif- ferentiate mesenchymal tumors of the uterine corpus, due to their many overlapping features. In most cases, the gross pathology of mixed endometrial stromal and smooth muscle tumor differs from that of pure endometrial stromal and pure smooth muscle tumors. A 59-year-old postmenopausal woman presented with vaginal spotting, low abdominal pain, and an uterine mass. Subsequent pelvic magnetic resonance imaging revealed a 4.0x3.8x3.4-cm sized uterine mass with enhancement. The mass showed restricted diffusion on diffusion-weighted images, and thus, was suspected to be uterine sarcoma rather than degenerative leiomyoma. Levels of tumor markers, CA 125, CA 19-9, and SCC, were within their normal ranges. The patient underwent exploratory laparotomy. Morphological and immunohistochemical evaluations were performed, and a final diagnosis of mixed endometrial stromal and smooth muscle tumor of the uterus was rendered. Her postoperative course was uneventful, and aromatase inhibitor adjuvant therapy was administered.

Ductulo-insular pancreatic endocrine tumor with amyloid deposition: report of a case.

We report a case of ductulo-insular pancreatic endocrine tumor (DI-PET) in a 50-year-old woman. The patient presented with symptoms and signs of hypoglycemia, and a small tumor in the uncus of the pancreas was extirpated. The tumor predominantly consisted of a neuroendocrine tumor (NET) of grade 2, which surrounded a minor component of ductular proliferation accompanied by a desmoplastic stroma. Both components were largely juxtaposed but admixed with each other in small areas. The NET component was immunoreactive for insulin and accompanied by the marked deposition of amyloid in the stroma. The ductular component consisted of a haphazard proliferation of ductules showing mildly atypical cytological features and immunoreactivities for cytokeratins 7 and 19. DI-PET is a rare composite neoplasm that should be distinguished from mixed ductal-neuroendocrine carcinoma because of the marked differences in treatment modalities and prognoses between the tumors. DI-PET associated with stromal amyloid deposition has not been reported to date. The 'transdifferentiation' of NET cells into ductular cells is considered as the most plausible histogenetic mechanism of this tumor, although other possibilities, such as an origin from a primitive endodermal stem cell or the induction of ductular proliferation by stimulation with NET-derived humoral factors, cannot be excluded.

Papillary glioneuronal tumor with a high proliferative component and minigemistocytes in a child.

Papillary glioneuronal tumor (PGNT) is a rare type of primary brain tumor. Although PGNT has traditionally been defined as a clinically indolent neoplasm, several cases with high proliferative activity and tumor recurrence have recently been reported. We report a case of PGNT in a 12-year-old boy who presented with epilepsy and harbored a 64 mm cystic tumor with a high proliferative component in the right temporal lobe. (11) C-methionine positron emission tomography (PET) showed high uptake in the solid mass. Gross total resection of the tumor mass was achieved and the patient became seizure-free without any neurological deficits. Histologically, the tumor contained two distinct areas of a vasocentric papilliform structure and a desmoplastic component. Minigemistocytic cells and small necrotic regions were observed adjacent to the pseudopapillae. Immunohistochemical analyses revealed both glial and neuronal differentiation. The Ki-67 proliferation index was high (14%) in the area corresponding to the high uptake region in the (11) C-methionine PET. No tumor recurrence was observed 20 months after surgery. High proliferative PGNTs are rare and to our knowledge this is only the third pediatric case of PGNT with atypical features reported in the literature. Hence, we here review the reported cases of PGNT and discuss the clinical, radiological and histological features of this malignancy.

Solid-pseudopapillary neoplasms of the pancreas: clinical and pathological features of 33 cases.

PURPOSE: Solid-pseudopapillary neoplasms (SPNs) are rare pancreatic tumors, with a low potential for malignancy. The clinical and pathological features of 33 SPNs were reviewed. METHODS: This study conducted a retrospective analysis of 33 patients who underwent surgery for a pathologically confirmed SPN from 2000 to 2011. RESULTS: Thirty of the 33 patients (91 %) were female, and the median age at diagnosis was 29.2 years (range 12-59). The most common symptom was abdominal discomfort with dull pain (58 %). Others included asymptomatic lesions that were only detected incidentally during imaging (21 %), a palpable abdominal mass (15 %) and indigestion (6 %). All 33 patients underwent surgery with a curative intent and 3 (9 %) underwent laparoscopic surgery. The mean diameter of the tumors was 4.9 cm (range 2-15 cm), and they occurred in the head (9, 27 %), neck (5, 15 %), body or tail (19, 58 %) of the pancreas. One patient had lymph node metastases, one patient had portal venous invasion and 8 patients had perineural invasion. The patient follow-up ranged from 4 to 118 months, and 32 patients were alive and well without recurrence. One patient relapsed 10 months after distal pancreatectomy with splenectomy and underwent a second surgery via laparotomy. Unfortunately, the patient died of multiple organ failure 12 days after the second surgery. CONCLUSION: SPNs are rare neoplasms with malignant potential but excellent prognosis. Adequate surgical resection, including laparoscopic surgery, may therefore be performed safely and is associated with a long-term survival, even in invasive cases.

Mixed schwannoma with meningioma - report on 2 cases of unusual tumor with review of literature.

We present 2 rare cases of mixed schwannoma with meningioma. The first case was sporadic, in a 38-year-old female in cervical spine (C2). The second case was a 24-year-old female, associated with NF-2, involving bilateral cerebellopontine angle with extension into the left cavernous sinus, sellar region with erosion of the petrous ridge and multiple intradural extramedullary lesions in the spinal cord suggestive of neurofibromas. To date only 12 cases of such tumors are documented in the literature. To the best of our knowledge this is the first case of sporadic mixed schwannoma with meningioma in cervical spine (C2).

Expression of p21 is dependent on or independent of p53 in carcinoma ex pleomorphic adenoma (undifferentiated and adenocarcinoma types).

Our study is aimed to characterize alteration in the immunohistochemical expression of p21 and p53 in normal tissue of the salivary gland surrounding carcinoma arising in pleomorphic adenoma, and the tumor cells of carcinoma arising in pleomorphic adenoma as well as to identify whether the induction of expression p21 is dependent on or independent of p53 in carcinoma arising in pleomorphic adenoma. A selected series of 27 cases of carcinoma ex pleomorphic adenoma (undifferentiated and adenocarcinoma types) was examined. The results showed that p21 and p53 expression was negative in the most components of normal tissue of the salivary gland surrounding carcinoma arising in pleomorphic adenoma. p21 was strongly expressed in carcinoma cells in 9 (33.3%) cases out of 27. p53 was strongly expressed in carcinoma cells in 10 (37%) cases out of 27. Also a co-expression of p21 and p53 showed negative nuclear staining in 9 cases, while 8 cases expressed positive staining. p21 expressed negative nuclear staining in 4 cases but p53 expressed positive staining in the same cases. p21 expressed positive nuclear staining in 6 cases but p53 expressed negative nuclear staining in the same cases. Our data suggest that inactivation of p53 and p21 may play an important role in the evolution of carcinoma ex pleomorphic adenoma. Also p21 behaves as dependent on or independent of p53 in carcinoma arising in pleomorphic adenoma.

Hybrid Carcinoma of the Parotid Gland: An Extremely Rare Three Cases with an Immunohistochemical Analysis and a Review of the Literature.

Salivary hybrid carcinoma (HC) is defined as when two or more kinds of carcinoma exist at the same location in a single mass. We reestimated and examined three cases of salivary gland HC. Case 1 involved a 76-year-old male. Case 2 involved a 74-year-old female. Case 3 involved a 66-year-old male. Histologically, case 1 involved a combination of salivary duct carcinoma (SDC) and squamous cell carcinoma (SqCC). Immunohistochemically, the former was positive for gross cystic disease fluid protein (GCDFP)-15 and androgen receptor (AR). Case 2 involved a combination of SqCC and neuroendocrine carcinoma. Immunohistochemically the latter was positive for synaptophysin and neural cell adhesion molecule (NCAM). Case 3 involved a combination of SDC and epithelial-myoepithelial carcinoma (EMC). Immunohistochemically, the former was positive for GCDFP-15 and AR, whereas the inner cells of the latter were positive for cytokeratin 7, and the outer cells of the latter were positive for actin. Because of the transitional zone between SDC and EMC, it was speculated that high-grade SDC arose from low-grade EMC.

Increased alpha-B-crystallin expression in mammary metaplastic carcinomas.

AIMS: Mammary metaplastic carcinoma is a rare breast carcinoma, and may present diagnostic difficulty. Alpha-B-crystallin has been recently reported to be expressed in basal-like and metaplastic carcinomas. METHODS AND RESULTS: Thirty-three metaplastic carcinomas, 44 conventional high-grade carcinomas and 28 mesenchymal spindle cell neoplasms as controls were assessed for their expression of αB-crystallin and conventional basal-like phenotypic markers CK5/6, CK14, p63, c-kit and epidermal growth factor receptor (EGFR) by immunohistochemistry. Alpha-B-crystallin staining was positive in 68% of the metaplastic carcinomas with cytoplasmic staining in all tumour cell components. CK5/6, CK14, p63, c-kit and EGFR stained 43%, 68%, 45%, 21% and 25% of the metaplastic carcinomas, respectively. Combining these markers, 84% of the metaplastic carcinomas expressed either αB-crystallin or CK14. In comparison, only 14% (six cases) of conventional high-grade carcinoma and 7% (two cases) of mesenchymal spindle cell neoplasm expressed αB-crystallin; all but one of these carcinomas were ER/PR/HER2 triple-negative. CONCLUSIONS: Using αB-crystallin for diagnosis of metaplastic carcinoma gives a 68% sensitivity, 88% specificity, 74% positive predictive value, 85% negative predictive value and 78% accuracy. The sensitivity is enhanced to 84% with combinations of αB-crystallin/CK14. Alpha-B-crystallin may be used as an adjunct marker in the diagnosis of metaplastic carcinoma.

Mixed squamous cell and glandular papilloma of the lung: a case study and literature review.

Mixed squamous cell and glandular papilloma (mixed papilloma) of the lung is an extremely rare neoplasm, with only 10 cases reported so far in the English literature. We present a case study of endobronchial mixed papilloma with immunohistochemical and etiological investigations. A 49-year-old male with a smoking history complained of hemoptysis, presented with a lung mass closely adjacent to large vessels in the computed tomography findings, and underwent lobectomy. The 3.0-cm sized polypoid tumor was histologically diagnosed as endobronchial mixed papilloma. Immunohistochemically, intracellular mucin was positive for MUC5AC, which is expressed in tracheobronchial goblet cells. CAM5.2 and CK19 were diffusely positive, indicating that the tumor originated from the columnar epithelium by squamous metaplasia. CEA and CA19-9 were focally positive. A human papillomavirus (HPV) investigation with in situ hybridization using a wide spectrum probe and a newly-developed PCR system did not detect any HPV infection. Including this case with a detailed HPV investigation, all of the reported cases of mixed papilloma were HPV-negative, and a literature review including newly-reported cases indicated a high frequency of smoking in such cases. Endobronchial mixed papillomas might have a smoking-related etiology.

Combined tubular adenocarcinoma and hepatoid adenocarcinoma arising in Barrett esophagus.

Hepatoid adenocarcinoma arising in the esophagus is extremely rare. To date, there are only 3 cases in the world English literature. We report the fourth case here. A 76-year-old Japanese man was admitted to our hospital because of the deterioration of nephritic syndrome. He presented with chest burn, and the endoscopic examination of upper digestive tract disclosed the tumor in the lower esophagus. The subtotal esophagectomy was undertaken because of esophageal cancer. The postoperative histologic examination showed the finding of combined tubular adenocarcinoma and hepatoid adenocarcinoma arising in Barrett esophagus. Immunohistochemically, hepatoid adenocarcinoma cells were positive for a-fetoprotein, hepatocyte, a1-antitrypsin, a1-antichymotrypsin, and CDX2, but negative for MUC5AC and MUC6. Esophageal hepatoid adenocarcinoma seems to be closely associated with Barrett esophagus and show the intestinal phenotype rather than gastric phenotype.

Mixed micropapillary-ductal carcinomas of the breast: a genomic and immunohistochemical analysis of morphologically distinct components.

Micropapillary carcinomas (MPCs) can present as a rare histological special type of breast cancer; however, this histological type is more frequently found admixed with invasive ductal carcinomas of no special type (IDC-NSTs). We have previously demonstrated that pure MPCs constitute a distinct entity at the morphological and genetic levels. Here, we sought to determine whether mixed MPCs have genomic aberrations similar to those found in pure MPCs, and to investigate whether the distinct morphological components of MPCs harbour different genetic aberrations. Using high-resolution microarray comparative genomic hybridization (aCGH), we profiled a series of 10 MPCs of mixed histology and 20 IDC-NSTs matched for grade and oestrogen receptor (ER) status. In addition, we generated tissue microarrays containing a series of 24 pure and 40 mixed MPCs and performed immunohistochemical analysis with ER, progesterone receptor (PR), Ki-67, HER2, cytokeratin (CK) 5/6, CK14, CK17, EGFR, topoisomerase-IIalpha, cyclin D1, caveolin-1 and E-cadherin antibodies. In situ hybridization was employed to evaluate the prevalence of HER2, TOP2A, EGFR, CCND1, MYC and FGFR1 gene amplification. Our results demonstrate that mixed MPCs harbour similar patterns of genomic aberrations and phenotype (82.5% luminal and 17.5% HER2) compared to pure MPCs. A comparison between the distinct morphological components of mixed MPCs in a pairwise fashion revealed that both components harbour strikingly similar genomic profiles. When compared to grade- and ER-matched IDC-NSTs, mixed MPCs significantly more frequently harboured amplification of multiple regions on 8q (adjusted Fisher's p value < 0.05). Furthermore, mixed MPCs displayed higher proliferative rates than grade- and ER-matched IDC-NSTs. Our results suggest that micropapillary differentiation in breast cancer may identify a subgroup of more aggressive ER-positive breast carcinomas, even in those featuring a mixed histology, and that mixed MPCs are more closely related to pure MPCs than to IDC-NSTs.

Salivary gland-type tumors of the breast: a spectrum of benign and malignant tumors including "triple negative carcinomas" of low malignant potential.

Salivary gland-type neoplasms of the breast are uncommon and comprise numerous entities analogous to that more commonly seen in salivary glands. The clinicopathologic spectrum ranges from benign to malignant but there are important differences as compared with those of their salivary counterpart. In the breast, benign adenomyoepithelioma is recognized in addition to malignant one, whereas in the salivary gland a histologically similar tumor is designated as epithelial-myoepithelial carcinoma without a separate benign subgroup. Mammary adenoid cystic carcinoma is a low-grade neoplasm compared with its salivary equivalent. It is also important to appreciate that in contrast to "triple negative" conventional breast carcinomas with aggressive course, most salivary-type malignant breast neoplasms behave in a low-grade manner. Most of these tumors are capable of differentiating along both epithelial and myoepithelial lines, but the amount of each lineage-component varies from case to case, contributing to diagnostic difficulties. Well established examples of this group include pleomorphic adenoma, adenomyoepithelioma, and adenoid cystic carcinoma. Another family of salivary gland-type mammary epithelial neoplasms is devoid of myoepithelial cells. Key examples include mucoepidermoid carcinoma and acinic cell carcinoma. The number of cases of salivary gland-type mammary neoplasms in the published data is constantly increasing but some of the rarest subtypes like polymorphous low-grade adenocarcinoma and oncocytic carcinoma are "struggling" to become clinically relevant entities in line with those occurring more frequently in salivary glands.

Primary spinal pleomorphic xanthoastrocytoma.

Pleomorphic xanthochromic astrocytoma primarily of the spinal cord is a rare entity. The case is possibly the fifth such report. Complete surgical excision is the essential requirement for good survival. In the absence of any clearly laid down protocols of adjuvant treatment, anecdotal reports support treatment with chemotherapy alone or both chemotherapy and radiotherapy.

Pseudoangiomatous stromal hyperplasia in a complex neoplastic lesion involving anogenital mammary-like glands.

Anogenital mammary-like glands (AMLG) may give rise to various pathologic lesions identical to those known in mammary pathology. Pseudoangiomatous stromal hyperplasia (PASH), a relatively frequent hormonal change associated with different benign and malignant processes in the breast, was only once mentioned in the literature concerning the pathology of AMLG. We present here a new case of PASH in a lesion of AMLG. The present case of PASH is remarkable because of its occurrence within a complex lesion evidencing the changes identical to or reminiscent of blunt duct adenosis, fibroadenoma and hidradenoma papilliferum.

Calcification and ossification in eccrine mixed tumors: underrecognized feature and diagnostic pitfall.

BACKGROUND: Eccrine mixed tumors of the skin are rare adnexal neoplasms, and their morphological spectrum is not well established. OBJECTIVE: To highlight the variation of the mesenchymal component of eccrine mixed tumors. METHODS: Among 70, 000 skin biopsies, 5 were diagnosed as eccrine mixed tumors. Cases were studied for clinical, histopathological, and immunohistochemical features (S-100, cytokeratin, epithelial membrane antigen, carcinoembryonic antigen, estrogen receptors, and herceptin receptor (HER-2)). RESULTS: Lesions were well-circumscribed dermal or subcutaneous nodules. Epithelial elements were small round tubules, cords, and individual cell aggregations being larger at the periphery and smaller toward the center. No signs of follicular or sebaceous differentiation were seen. The stroma was mucinous and chondroid, calcification ranging from little to extensive with bone formation in 3 examples giving the impression of a chondroid or osseous neoplasm. S-100 stained epithelial and chondroid stromal cells. Cytokeratin highlighted the silhouette of epithelial elements. Estrogen receptors, EMA, carcinoembryonic antigen, and HER-2 were negative. CONCLUSIONS: Eccrine mixed tumors are distinctive tumors that should not be lumped together with their apocrine counterparts. Extensive ossification and calcification may be present and may eclipse by far the epithelial elements.

Squamomelanocytic tumor: an unusual and distinctive entity of uncertain biological potential.

We report a case of a squamomelanocytic tumor of the skin. Clinically, the lesion was felt to be a melanocytic or vascular tumor but histologically was characterized by epithelioid cells with focal squamous differentiation. Immunohistochemical staining showed that half of cells stained with MNF116 and a smaller proportion stained with S100 and Melan A. A third population did not stain with either set of antigens. The lesion has some similarities to a melanocytic matricoma but no evidence of matrical differentiation. The biological potential of this distinctive tumor is not known because so few have been reported.

An unusual squamo-melanocytic tumor of uncertain biologic behavior: a variant of melanoma?

The presence of two intermingled malignant components within the same cutaneous tumor is rare. Herein, we report a case of an exceedingly rare squamo-melanocytic tumor, favored to be a melanoma variant. Although the biologic behavior and prognostic significance of this tumor remain to be established, this unique case reaffirms the potential morphologic diversity of melanoma. We review the literature reporting similar neoplasms and discuss the potential histogenesis of this squamo-melanocytic tumor.

Anaplastic large cell lymphoma: another entity in the differential diagnosis of small round blue cell tumors.

We saw in consultation a biopsy specimen from a 6-year old girl with anaplastic lymphoma kinase (ALK)-positive anaplastic large cell lymphoma (ALCL). The tumor arose in soft tissue of the neck, and diagnostic tissue was obtained by core needle biopsy. Histologically, the neoplasm was cellular without pattern. Immunohistochemical workup with a large panel of antibodies at another institution showed immunoreactivity for NB84 and neuron specific enolase (dim). Antibodies specific for CD3, CD20, and CD45/LCA were negative; CD30 or ALK were not assessed. Electron microscopy showed cytoplasmic structures thought to be neurosecretory granules. The neoplasm was interpreted initially as a neuroblastoma. At the time of our review, we considered the possibility of ALCL. Immunohistochemical analysis for CD30 showed bright, uniform expression and ALK was positive in a nuclear and cytoplasmic pattern, confirming the diagnosis of ALK+ ALCL. The purpose of this review is to discuss ALK+ ALCL and many of the other entities included under the rubric of small round blue cell tumor, with a focus on tumors that occur in children.