PERIVASCULAR SPACE IN ECCRINE SPIRADENOMA - A CLUE TO ITS HISTOLOGICAL DIAGNOSIS

Perivascular spaces were found to represent a useful histological clue to the diagnosis of eccrine spiradenoma. They were observed in eight of nine eccrine spiradenomas but not in syringomas, nodular basal cell carcinomas, or glomangiomas. Perivascular spaces in spiradenomas cons isted of variably sized spaces around one or more central blood vessel s, bordered at the periphery by a palisade of tumor cells and lined at both sides by basement membrane collagen type IV. Perivascular spaces contained variable numbers of T lymphocytes in all cases and could un dergo fibrosis, cystic dilation, or hyalinization. In analogy to simil ar structures in thymomas, we suggest that perivascular spaces in spir adenomas are involved in the traffic of lymphocytes toward the tumor.