Ovarian malignant mixed mesodermal tumor with neuroectodermal differentiation: a multifaceted evaluation.

Malignant mixed mesodermal tumors (MMMTs) of the ovary are rare, highly aggressive neoplasms that arise most commonly in postmenopausal women. Histologically, they consist of a mixed population of malignant epithelial and mesenchymal elements. Neuroectodermal differentiation in ovarian MMMTs is exceedingly uncommon, with only a few case reports in the literature. We present a case of an ovarian MMMT with neuroectodermal differentiation in a 78-year-old female patient. Histologically, the tumor was composed of epithelial, mesenchymal, and neuroectodermal elements. The neuroectodermal component was predominantly that of a medulloepithelioma, with scattered areas displaying features of an anaplastic astrocytoma, including rare ganglion cell differentiation. The neuroectodermal component showed immunoreactivity for glial fibrillary acidic protein, synaptophysin, and S100 protein. Ultrastructurally, the neuroectodermal component was populated by cells with irregular nuclei, finely dispersed chromatin, rudimentary cell junctions, and a delicate basement membrane, all of which have been described in medulloepitheliomas. DNA ploidy analysis was also performed on the various components of the tumor and compared with 3 additional cases of MMMT without neuroectodermal differentiation and 2 ovarian immature teratomas. Our findings suggest that the neuroectodermal component may arise from a separate clone or at least evolves at an earlier stage of tumor development.

Cutaneous clear-cell granular cell tumors: the histologic description of an unusual variant.

BACKGROUND: Granular cell tumors (GCTs) are neoplasms showing nerve sheath differentiation that can arise in the skin but, to our knowledge, have not been associated with significant clear-cell morphology. METHODS: Two patients developed four separate GCTs with distinctive, diffuse clear-cell change, which completely camouflaged the primary differentiation. The morphology, histochemistry and immunohistochemistry of the lesions are described and are compared with the presence and extent of clear-cell change in 14 other cases of GCTs. RESULTS: The index cases were relatively broad proliferations with uniform diffuse clear-cell change and only minimal overlying epidermal hyperplasia. Prominent lymphoid nodules were present at the periphery. These clear-cell granular tumors were positive for S-100 protein, p75, CD68, NKI/C3 and neuron-specific enolase and were negative for epithelial mucin, periodic acid-Schiff, carcinoembryonic antigen, HMB-45, Melan-A, smooth muscle actin, Leu7, synaptophysin, CD34, factor XIIIa, epithelial membrane antigen and cytokeratin. Three of the fourteen comparison cases were found to have no clear-cell change, eight showed focal clear-cell change and three showed moderate clear-cell change. CONCLUSIONS: The distinctive morphology and the immunohistochemical results are discussed in the context of the differential diagnosis of clear-cell cutaneous tumors.

Fatal interstitial pulmonary fibrosis in anti-Jo-1-negative amyopathic dermatomyositis.

Amyopathic dermatomyositis (DM) describes a subpopulation with the cutaneous eruption of DM, but without muscle involvement. Interstitial pulmonary fibrosis is a recognized complication of DM, often correlated with antisynthetase enzymes, such as anti-Jo-1. We describe a case of fatal IPF in a patient with anti-Jo-1 antibody-negative amyopathic DM.

Marginal zone and mantle cell lymphomas: assessment of cytomorphology in subtyping small B-cell lymphomas.

The diagnosis of malignant lymphomas by fine-needle aspiration biopsy (FNAB) is increasing in utilization. The cytomorphologic distinction among the small B-cell lymphomas may be quite difficult. We are unaware of anyone who has compared directly mantle cell lymphoma (MCL) and marginal zone lymphoma (MZL) in FNAB. Our major goal was to examine the cytomorphologic attributes of MCL and MZL and to look for features distinctive of or suggestive of either neoplasm. Seven immunophenotypic MCL and seven immunophenotypic MZL aspirates were evaluated for a number of cytomorphologic features in direct smears. Features favoring MCL include a relatively monomorphic cellular population, prominent nuclear membrane contour irregularities, and mitotic figures. Conversely, a polymorphic cellular population suggested MZL. However, due to extensive overlap of specific cytologic features, the two lymphomas cannot be definitively distinguished based solely on cytomorphology. Although there are cytomorphologic attributes suggestive of either MCL or MZL, considerable overlap exists. Based on an individual case basis, the distinction cannot be made reliably by morphology alone; ancillary studies, e.g., immunophenotyping, are essential.