Syringocystadenoma papilliferum: a rare breast tumor in a young boy

Current Diagnosis and Treatment Options for Cutaneous Adnexal Neoplasms with Apocrine and Eccrine Differentiation

Adnexal tumors of the skin are a rare group of benign and malignant neoplasms that exhibit morphological differentiation toward one or more of the adnexal epithelium types present in normal skin. Tumors deriving from apocrine or eccrine glands are highly heterogeneous and represent various histological entities. Macroscopic and dermatoscopic features of these tumors are unspecific; therefore, a specialized pathological examination is required to correctly diagnose patients. Limited treatment guidelines of adnexal tumor cases are available; thus, therapy is still challenging. Patients should be referred to high-volume skin cancer centers to receive an appropriate multidisciplinary treatment, affecting their outcome. The purpose of this review is to summarize currently available data on pathogenesis, diagnosis, and treatment approach for apocrine and eccrine tumors.

Syringocystadenoma papilliferum on the male nipple

Syringocystadenoma papilliferum is a rare benign adnexal tumor that most frequently arises from an organoid nevus on the head and neck. Occurrence of this tumor on the male breast is extremely rare. A 74-year-old Japanese man presented with a nodule on his left nipple. Histopathological findings were typical for syringocystadenoma papilliferum. Ultrastructurally, constituent epithelial cells of the tumor were divided into three types. We focused on one cell type, undifferentiated clear cells, which have been suggested to be pluripotent cells bearing stem cell nature in syringocystadenoma papilliferum. Immunohistochemically, the tumor cells were negative for cytokeratin 15, which is known as a relatively specific marker for multipotent stem cells in the follicular bulge. We speculated that the clear cells are slightly differentiated toward apocrine rather than stem cells. We also ruled out the possibility of a relationship between the clear cells and Toker cells, which have a clear cytoplasm and are present in the areola region. Dermoscopic examination revealed amorphous milky white areas that corresponded to the pathological findings of luminal deposition of the tumor.