8403/3 Malignant eccrine spiradenoma


ICD-O-3 topography code: C44
ICD10: C44

Spiradenocarcinoma is a very rare, aggressive carcinoma of the sweat glands arising from malignant transformation of a long standing spiradenoma. The tumour may arise in any site of the body but is most commonly observed in the upper extremities, followed by the lower extremities, trunk, and head and neck. Tumour size ranges from 0.8 to 10 cm.
All spiradenocarcinomas contain areas of the benign precursor lesion with the typical well-defined dermal nodules composed of two cell types; apart from that, two different histologic patterns can be observed:
1) Gradual transition from benign to malignant. The dual cell population of the spiradenoma imperceptibly merges with the monomorphous cell population of the carcinoma. Poorly defined cell nests and cords replace the structural pattern of spiradenoma.
2) No transition from benign to malignant; the malignant areas are adjacent to and demarcated from the spiradenoma.
Advanced stages of both subtypes display necrosis, haemorrhage, and infiltrative growth.
Spiradenocarcinoma mainly affects middle-aged patients (mean age 55 years). The clinical course is aggressive; typical are multiple local recurrences and eventual widespread metastases, resulting in death. Metastases develop most often in lymph nodes, bones, and lungs. Management is primarily surgical1
LeBoit PE, Burg G, Weedon D, Sarasin A (Eds.)
World Health Organization Classification of Tumours. Pathology and Genetics of Skin Tumours
3rd Edition
IARC Press: Lyon 2005