Granular cell variant of epithelioid cell histiocytoma.

Classic granular cell tumors (GCTs) stain strongly and uniformly positive for S100 protein and are believed to show Schwann cell derivation. Polypoid cutaneous tumors composed of cells with large nuclei and abundant granular cytoplasm that do not stain for S100 protein or show apparent Schwannian differentiation have been reported by several groups under names including "primitive polypoid granular cell tumors," "dermal nonneural granular cell tumor," and "primitive nonneural granular cell tumors of skin." We report a polypoid tumor composed of S100-negative epithelioid cells with abundant eosinophilic granular cytoplasm that meets diagnostic criteria for (primitive polypoid dermal) nonneural GCT but also meets criteria for a granular cell variant of epithelioid cell histiocytoma. We have identified a single previous report of a similar lesion. We report the immunohistochemical characteristics of these lesions and address how they are best classified.

[Inflammatory malignant fibrous histiocytoma of the spermatic cord infiltrating an inguinal leiomyoma. Case report with conceptual and bibliographic reviews]. / Fibrohistiocitoma maligno "inflamatorio" de cordón espermático con infiltración sobre un leiomioma inguinal. Presentación de 1 caso con revisión conceptual y de la literatura.

OBJECTIVES: To study paratesticular malignant fibrous histiocytomas (FHM) from the clinical, histological, immunohistochemical and histogenetic, point of view. METHODS: Through Medline and not index-linked search of international scientific literature we have found a total of 77 cases of paratesticular FHM that globally create diagnostic, terminological and therapeutic problems. RESULTS: We include the case number 78 of FHM of spermatic cord, that presents a few special characteristics (not described before) of cutaneous fistula and infiltration of an inguinal leiomyoma, with histological and immunohistochemical confirmation. We performed a conceptual review of this type of tumours, including the evaluation of contradictions and reclassifications that has undergone from its first description, which causes that they are underestimated and their real prevalence in international series is very variable: from 7 to 37% of paratesticular sarcomas. Also, the fact of their low incidence has determined the lack of protocols for diagnosis and treatment. CONCLUSIONS: Paratesticular tumours, although infrequent, have a high rate of malignancy. The FHM concept has varied throughout the last 15 years. Today, this term is synonymous of pleomorphic undifferentiated sarcoma and has been an exclusion diagnosis (Vimentin [+]/ CD 68 [+]--occasionally--without ultrastructural differences), reserving the inflammatory subtype for which they have an inflammatory and histiocytic component. The accomplishment of an intraoperatory biopsy is essential in this location, since it is even difficult to know preoperatively, if a lesion is benign or malignant. The differential diagnosis is only solved after microscopic and inmunohistochemical study. Leiomyoma next to this location (inguinal) could be diagnosed and confused with a nodule of the main FHM. Their immunophenotype allowed us to diagnose it not only as leiomyoma (myogenic markers were positive -non skeletal muscle-), but also to observe the infiltration by the FHM.