Ovarian strumal carcinoid containing appendiceal-type mucinous tumor patterns presenting as pseudomyxoma peritonei.

We report for the first time a case of ovarian strumal carcinoid containing both trabecular carcinoid and mucinous glands lined by both goblet and neuroendocrine cells and a low-grade mucinous neoplasm that presented clinically as pseudomyxoma peritonei in the absence of appendiceal lesion in a 58-yr-old woman. Histologically, there were both a tall columnar cell epithelial component lacking neuroendocrine cells, showing the scalloped contours and subepithelial clefts of low-grade appendiceal-type neoplasms and a mixed goblet cell neuroendocrine element. Characteristically, both reproduced appendiceal neoplastic phenotypes in a teratoid fashion. In addition, we present previously unreported oncocytic and mucinous changes in the thyroideal components of strumal carcinoid. This case represents a rare instance of pseudomyxoma peritonei of primary ovarian origin and is an example of multiple somatic teratoid endodermal differentiations of the different sections of the embryonal gut: foregut represented by thyroid, midgut by both mucinous appendiceal components, and hindgut by trabecular carcinoid.

Lipomatous variant of angiomyofibroblastoma involving the vulva: report of 3 cases of an extremely rare neoplasm with discussion of the differential diagnosis.

We report 3 cases of the extremely rare lipomatous variant of angiomyofibroblastoma (AMF) involving the vulva of women aged 35, 45, and 47. The lesions ranged in size from 2.5 to 12 cm in maximum dimension and the largest had a gross "fatty" appearance. The percentage of adipose tissue was approximately 50% in 1 case and over 90% in the other 2. In all the cases, there was a background of typical AMF with bland spindled and epithelioid cells arranged around blood vessels, although in the cases with >90% adipose tissue, this was subtle and diffusely interspersed with the adipose tissue. In all the cases, the spindled and epithelioid cells were positive with estrogen receptor. Given the morphologic features, misdiagnosis as a lipomatous neoplasm is likely, especially in cases with a minor component of typical AMF. We review the literature on lipomatous AMF and discuss the differential diagnosis.

A diagnostic immunohistochemical panel for yolk sac (primitive endodermal) tumours based on an immunohistochemical comparison with the human yolk sac.

AIMS: To establish a diagnostic immunohistochemical panel for various histotypes of yolk sac (primitive endodermal) tumours (YSTs) by comparison with the human yolk sac (HYS) immunophenotype. METHODS AND RESULTS: Twenty-five YSTs showing either classical patterns (CPs) of histology (microcystic/reticular, n = 14; polyvesicular, n = 1; and hepatoid, n = 1) or somatic glandular patterns (SGPs; n = 9) were analysed for expression of α-fetoprotein (AFP), glypican-3 (GPC3), villin, hepatocyte paraffin-1 (HepPar-1), CDX2, SALL4 and LIN28. AFP expression was constantly heterogeneous in CPs but tended to be focal/absent in SGPs. GPC3 was diffuse in CPs but heterogeneous (seven cases) or focal/absent (two cases) in SGPs. HepPar-1 expression was focal in all but three cases (diffuse in one CP-hepatoid and two SGPs). CDX2 positivity was focal in CPs but heterogeneous (seven cases) or diffuse (two cases) in SGPs. Villin, SALL4 and LIN28 were diffusely positive in nearly all cases. CONCLUSIONS: CPs reproduce the immunophenotype of HYS and early endoderm with variable expression of both AFP and markers of early gut or hepatic differentiation. SGPs with intestinal differentiation often have incomplete immunophenotypes. A differential diagnosis panel, including both markers of pluripotentiality (SALL4 and/or LIN28) and endoderm (AFP, GPC3 and villin), is proposed. It identifies overlapping multidifferentiation of primitive and somatic immunophenotypes, supporting the recently proposed term of primitive endodermal tumours.

Ectopic Complete Hydatidiform Mole Presenting as an Adnexal Tumor in a Postmenopausal Patient.

Hydatidiform mole (HM) is rare in postmenopause, with only 7 cases reported. The occurrence of ectopic HM is also rare, with 26 fully documented tubal cases. We are not aware of any reported cases of ectopic HM in a postmenopausal patient. In a 51-year-old patient with 3 years amenorrhea, surgery revealed a necrotic, hemorrhagic mass involving the right peritubal space. Microscopically, chorionic villi were seen within the hemorrhagic mass accompanied by circumferential trophoblast hyperplasia. Immunohistochemically, p57(kip2) positive nuclei were prominent in the extravillous (intermediate) trophoblast. The HER2 FISH expression was diploid, consistent with the diagnosis of an early complete HM.

Primary intermediate-grade cardiac myxofibrosarcoma with osseous metaplasia: an extremely rare occurrence with a previously unreported feature.

Primary cardiac myxofibrosarcoma (MFS) is a very rare cardiac tumor with no more than 22 cases reported in the literature, including our case. We report an MFS arising in the left atrium in a 65-year-old woman who presented with pneumonia and cardiac failure. The 9.5-cm mass was diagnosed by echocardiogram. Histopathology examination showed an intermediate-grade MFS with osseous metaplasia, a feature that has not been reported before.

Case report: Papillary mesothelioma of the peritoneum with foamy cell lining.

A 34-year-old female, with a history of continued asbestos exposure, presented with a papillary peritoneal mesothelioma with a diffuse, prominent clear foamy cell change, with microvacuolation in its papillary lining, that expressed cytokeratins 7, 5/6 and calretinin as well as nuclear WT-1 and apical membrane staining for thrombomodulin, podoplanin D2-40 and HBME-1. In contrast, lining cells were CD68 negative. Foamy cell change has been reported in isolated cases as solid cords but not as a diffuse change in the mesothelial papillary lining. This phenomenon prompts differential diagnoses with abdominal and renal papillary clear cell tumours, which were discarded after a characteristic mesothelial immunophenotype was demonstrated. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/4679576081031834.