Malignant Hidroacanthoma Simplex

Abstract

A case of malignant hidroacanthoma simplex is described. Histological examination revealed that the malignant cells had arisen from a tumor cell nest of benign hidroacanthoma simplex and invaded the dermis. Two years and 7 months after the excision of the original thigh lesion, a groin lymph node metastasis was discovered. The metastatic tumor cells in the lymph node were histologically similar to the carcinoma cells in the original thigh lesion and had enzymatic and ultrastructural features resembling eccrine sweat duct.

Porocarcinoma Arising in Pigmented Hidroacanthoma Simplex

“…The gross appearance of malignant HAS tended to vary, and there were nodular lesions or keratotic plaques with or without erosion and/or ulceration. [4][5][6][7][8][9][10][11] In the present case, the porocarcinoma portion was erosive with depigmentation, and such a case has been reported previously. 3 Therefore, clinical findings such as erosion and/or ulceration and depigmentation might be indicative of the malignant transformation of HAS.…”

“…12 Malignant variants of HAS are rare and have been reported under different names, such as malignant HAS, in situ porocarcinoma, eccrine porocarcinoma, and HAS with invasive growth. [2][3][4][5][6][7][8][9][10][11] Most cases developed from pre-existing benign HAS, 3,5,7,11 as did our present case. In a review of the literature on malignant HAS, 6 the ages of patients ranged from 50 to 87 years, with the majority of patients being over 70 years of age.…”

“…2 Malignant HAS is extremely rare, and most of the reported cases have coexisted with HAS and, thus, represent the malignant transformation of pre-existing HAS. [3][4][5][6][7][8][9][10][11] In general, poroid neoplasms are believed to be of eccrine gland origin but poroid neoplasms are currently categorized as being of either eccrine or apocrine origin and, in particular, poroma with follicular and/or sebaceous differentiation is referred to as apocrine poroma. 12 Among a variety of cutaneous tumors, pigmentation and secondary amyloid deposition are found most frequently in basal cell carcinoma and seborrheic keratosis.…”

Malignant Transformation of Benign Hidroacanthoma simplex

“…Malignant hidroacanthoma simplex, the malignant counterpart of hidroacanthoma simplex, is an extremely rare tumor. In previous studies, malignant transformation of benign hidroacanthoma sim plex was relatively frequent [4][5][6][7][8]. However, because no other case of malignant transformation occurring after cryotherapy has been reported, we do not think that this treatment played an important role in the malignant trans formation of this tumor.…”

“…Hidroacanthoma simplex, first described by Smith and Coburn in 1956 [1J, is a rare tumor considered to differentiate towards external cells of the acrosyringium [2,3]. Malignant transformation of hidroacanthoma simplex is extremely rare [4][5][6][7][8]. We report a case of tumor on the right ankle that initially showed histological features of benign hidroacanthoma simplex and malignant transformation in the specimen obtained 2 years later.…”