Manuel Rodríguez Sánchez

Papillary eccrine adenoma--a light-microscopic and immunohistochemical study.

We report a case of papillary eccrine adenoma. This benign cutaneous tumour had a diagnostic microscopic appearance that consisted of multiple dilated ducts lined by two or more layers of cells. The inner layer often formed intraluminal papillary projections of variable complexity. The lumina were filled by eosinophilic amorphous material. Immunoperoxidase studies showed carcino‐embryonic antigen in the luminal border of the ducts, but S‐100 protein was absent for tumoral ducts. We discuss the eccrine and apocrine differentiation of this neoplasm on the basis of the immunoperoxidase results. The differential diagnosis includes other cutaneous neoplasms with intraductal papillary proliferation.

Angioleiomyoma within a histiocytoma

We report an angioleiomyoma developed within a cellular histiocytoma on the calf of a 77‐year‐old man. The lesion consisted of a spherical nodule with two well‐defined concentric areas. The outer circular area was a cellular histiocytoma and the inner central area consisted of an angioleiomyoma. Immunoperoxidase investigations for desmin demonstrated positivity in the angioleiomyoma, whereas the histiocytoma positivity in the angioleiomyoma, whereas the histiocytoma remained negative. Serial sections of the lesion failed to demonstrate a connection between the angioleiomyoma and a normal vein which could have been trapped by the histiocytoma. The angioleiomyoma may have originated from a vessel in the histiocytoma.

An unusual benign neural tumour with stellate-cell morphology

We report a stellate‐cell dermal tumour which was studied by immunohistochemistry and electron microscopy. The stellate morphology of the tumour cells appeared to be due to retraction of their cytoplasm resulting in the emergence of intercellular spaces. Results of the immunohistochemical investigations were consistent with a neural tumour, but we could not assign it to any particular category of the known neural tumours. Therefore we have designated this tumour as an unusual, benign, neural‐tumour with stellate‐cell morphology.