A Clinicopathological Study of Nodular Hidradenoma: Reclassification of Nodular Hidradenoma According to Ackerman’s Criteria / 대한피부과학회지

ABSTRACT

Background@#Nodular hidradenoma is a relatively common benign cutaneous neoplasm, which usually presents as solitary intradermal nodule. In Korea, an extensive study on tumors with eccrine differentiation was performed in 2006; however, the study considered all eccrine tumors and detailed analysis of its differentiation was not performed. In addition, although most skin pathology textbooks classify it as a tumor showing eccrine differentiation, its differentiation remains controversial. @*Objective@#This study investigated clinicopathological features of nodular hidradenoma in Koreans at a tertiary referral center. @*Methods@#We retrospectively investigated 22 patients who presented with nodular hidradenoma at Yeungnam University Hospital between 2000 and 2021. Diagnosis was confirmed by histopathological examination in all the patients. @*Results@#About half of the lesions were located on the head and neck area (45.5%), followed by the trunk (31.8%). Histopathological examination revealed that tumor cells in most of the cases consisted of cuboidal and clear cells; however, in some cases there were several specific modified cells such as clear cells (9.1%), squamoid cells (4.5%), and poroid cells (22.7%). Considering the morphological characteristic of tubular structures, most cases (90.9%) showed apocrine differentiation, and only 2 cases (9.1%) showed eccrine differentiation. @*Conclusion@#Considering the characteristics of cells and tubular structures constituting tumors, it is reasonable to consider nodular hidradenoma as a tumor with apocrine differentiation rather than with eccrine differentiation, which had previously been the predominant classification. Furthermore, there still is no distinct marker for determining whether cells differentiate into eccrine or apocrine tissues and further studies are therefore needed.