Eccrine spiradenoma is now known as a benign sweat gland tumor that commonly affects young adults.
This high-grade eccrine carcinoma was noted to be arising from a preexisting eccrine spiradenoma, seen as sharply demarcated lobules composed of 2 cell populations (peripheral basaloid cells and central pale cells) arranged in nests and interanastomosing trabecula with scattered glandular lumina and focal cystic changes (Figure 3).
The malignancy almost always arises from a preexisting benign eccrine spiradenoma after a variable latent period, which may be as long as 75 years.
Malignant eccrine spiradenoma frequently shows focal squamous differentiation, which may be florid in rare instances.
3,11) Malignant eccrine spiradenoma metastasizes to regional lymph nodes, lungs, brain, and liver (in descending order of frequency).
Cases of Malignant Eccrine Spiradenoma Reported in the Literature * Case Age, y/ No.
Malignant eccrine spiradenoma with smooth muscle differentiation: histological and immunohistochemical study.
On the basis of pathologic findings, the differential diagnoses include eccrine adenocarcinoma not otherwise specified (NOS), porocarcinoma, apocrine carcinoma, malignant chondroid syringoma, and eccrine spiradenoma.
10) Similarly, malignant eccrine spiradenoma was excluded on the basis of the absence of benign eccrine spiradenoma cells.