BACKGROUND. Eccrine spiradenoma is a well-differentiated benign tumor of th
e sweat glands. Malignant change arising within eccrine spiradenoma is rare
OBJECTIVE. We describe a patient with malignant eccrine spiradenoma exhibit
ing both carcinomatous and sarcomatous differentiation,
METHODS. Case report and literature review.
RESULTS. A 37-year-old woman noted enlargement of a left axillary tumor tha
t had been present for 20 years. The tumor was resected and the specimen, m
easuring 3.0 cm x 1.5 cm, revealed an encapsulated benign eccrine spiradeno
ma as well as an undifferentiated carcinoma possessing both carcinomatous a
nd sarcomatous components, A transition zone was evident between the benign
eccrine spiradenoma and the undifferentiated carcinoma, suggesting that th
e latter had arisen from the benign tumor, The malignant areas consisted pr
incipally of undifferentiated carcinoma (70%), although squamous cell carci
noma (10%), adenocarcinoma (10%), and chondrosarcomatous (10%) components w
ere also present. Numerous mitotic figures were noted within the areas of m
alignant change, suggesting that the tumor was aggressive in nature, The pa
tient died of systemic metastases 7 months after diagnosis.
CONCLUSION. Although eccrine spiradenomas are usually benign, they can, on
rare occasions, undergo malignant transformation. This case report describe
s one such occurrence of malignant transformation of a benign eccrine spira
denoma that unfortunately resulted in the patient's death from systemic met
astases 7 months after diagnosis.