Spiradenoma is a benign epithelial neoplasm with eccrine or apocrine differentiation, arising from the sweat glands. It typically presents as a small (<1cm), solitary, well-circumscribed, firm dermal nodule (giant
Cotton DW, Slater DN, Rooney N, Goepel JR, Mills PM (1986)
Giant vascular eccrine spiradenomas: a report of two cases with histology, immunohistology and electron microscopy.
Histopathology 10: 1093-9
Noto G, Bongiorno MR, Pravata G, Arico M (1994)
variants have been described), most commonly in face and upper trunk. Spiradenoma shows significant morphologic overlap with cylindroma
Multiple nevoid spiradenomas.
Am J Dermatopathol 16: 280-4
Histologically, the lesion is characterized by round, smooth-bordered aggregates of basaloid cells, which extend over the full thickness of the dermis and sometimes into the subcutaneous fat. Two populations of neoplastic epithelial cells can be distinguished: at the periphery, small, dark basaloid cells with hyperchromatic nuclei predomiate, while larger pale cells with vesicular nuclei are more frequent near the centre. The tumour nodules contain abundant inflammatory cells (T lymphocytes, Langerhans cells). A characteristic finding are globules composed of basement membrane material, which are scattered throughout the entire nodule and sometimes surrounded by tumour cells in a pseudorosette fashion. The stroma is frequently oedematous with ectatic vessels.
Spiradenoma typically develops in adults (congenital cases have been reported
Schmoeckel C, Burg G (1988)
). Excision is facilitated by the sharp demarcation of the tumour from the surrounding tissue and is usually curative. Long-standing spiradenomas may progress to carcinomas
Am J Dermatopathol 10: 541-5
LeBoit PE, Burg G, Weedon D, Sarasin A (Eds.)
World Health Organization Classification of Tumours. Pathology and Genetics of Skin Tumours
IARC Press: Lyon 2005