Primitive nonneural granular cell tumor of the skin was first described by LeBoit et al in 1991 as "primitive polypoid granular cell tumor." Few cases have been reported to date, all being polypoid or deep well-delimited lesions and formed by large spindle or polygonal granular cells with moderate nuclear atypia and increased mitotic activity. This granular cell population does not have a Schwannian, myogenic, melanocytic, fibroblastic, histiocytic, or epithelial differentiation. We report a case that fully satisfies the criteria for primitive nonneural granular cell tumor of the skin and, in addition, shows an extensive desmoplastic stroma. This desmoplastic variant of primitive nonneural granular cell tumor, which to our knowledge has not been previously reported, should be recognized to appropriately face the differential diagnosis with the malignant granular cell tumor, whose criteria for malignancy cannot be applied to primitive granular cell tumors.
Myopericytoma is a perivascular myoid neoplasm of skin and soft tissues characterized by numerous thin-walled blood vessels surrounded concentrically by round to spindle myoid tumor cells, which shows α-smooth muscle actin and h-caldesmon coexpression and commonly negativity for desmin. These tumors arise predominantly in extremities of adult patients with benign clinical course. Based on the architectural pattern, there are various histologic variants as classical-solid myopericytoma, hemangiopericytoma-like myopericytoma, angioleiomyoma-like myopericytoma, myofibroma-like myopericytoma, hipocelular fibroma-like myopericytoma, intravascular myopericytoma, cellular immature myopericytoma, and malignant myopericytoma. The authors report a case that fully satisfies the morphological and immunohistochemical criteria for intravascular myopericytoma, which plantar location is not previously described in the literature. In addition, the authors discuss about its possible development from a preexistent cutaneous vascular malformation.
Germinotropic lymphoproliferative disorder (GLPD) is a poorly characterized lymphoproliferative entity, recently included in the World Health Organization classification of hematolymphoid neoplasms. The histological pattern of this disease comprises monotypic plasmablasts that involve the germinal centers of the lymphoid follicles (germinotrophism), forming confluent aggregates positive for both human herpes virus type 8 (HHV8) and Epstein-Barr virus. Currently, after 17 years of its first description, only 18 cases have been reported. In this article, we describe a case of a GLPD presenting in an immunocompetent 79-year-old woman with localized axillary lymphadenopathy, showing a prominent sinusoidal growth pattern, with no evidence of germinotrophism or extrasinusoidal spread. Stinking pleomorphism in tumor cells was also noted. An extension study has not revealed involvement of other groups of lymph nodes or extralymphoid sites. The patient is alive and has shown no relapse after 8 years follow-up (the longest follow-up reported period for this entity). This previously unrecognized pure sinusoidal growth pattern along with the striking pleomorphism in neoplastic cells closely mimics the appearance of an anaplastic large cell lymphoma. GLPD is not usually considered in such a setting, but it should be included in the differential diagnosis of sinusoidal proliferations. Our findings contribute to the expansion of the morphological spectrum of HHV8-associated lymphoproliferative lesions and aids in the characterization of the very infrequent GLPD entity.
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