Eccrine Syringofibroadenoma of Clear Cell Variant

A case report of reactive solitary eccrine syringofibroadenoma

Eccrine syringofibroadenoma is a very rare benign tumour of acrosyringium of eccrine sweat duct. Based on the evidences of known etiological factors, two forms have been proposed; reactive and nonreactive. Reactive forms are rarer, and on even rarer occasions, trauma complicated by secondary nonspecific infections may lead to the development of reactive eccrine syringofibroadenoma, as in our case. Here, we are documenting a case of reactive solitary eccrine syringofibroadenoma in a 65-year-old male presenting with coalescing, firm, pinkish, verrucous nodules and painful deep ulceration on the right sole preceded by trauma and secondary infection. Histopathologic revelation of distinctive microscopic findings confirmed the diagnosis in our case.

Eccrine Syringofibroadenomatosis of the Soles

Eccrine syringofibroadenoma is a rare adnexal tumor with acrosyringeal differentiation. It was first described by Mascaro in 1963. Its clinical presentation varies from a solitary nodule, keratotic papule, verrucous plaque, or palmoplantar keratoderma to multiple lesions with linear or diffuse distributions. Age at onset ranges from 16 to 80 years. Lesion distribution is wide and includes the face, back, abdomen, buttocks, extremities, and, rarely, nails. There are five subtypes of eccrine syringofibroadenoma. Histologically, eccrine syringofibroadenoma, independent of the subtype, is characterized by anastomosing cords of acrosyringeal cells forming ductal structures in a fibrovascular stroma and attached to the undersurface of the epidermis in multiple foci. In this article, we describe a 51-year-old woman diagnosed as having eccrine syringofibroadenomatosis.

Clear cell acanthoma with changes of eccrine syringofibroadenoma: reactive change or clue to etiology?

We observed two patients with solitary lesions showing features of clear cell acanthoma with underlying eccrine syringofibroadenoma-like changes. The pathogenesis of these entities has been debated since their original descriptions, with most recent literature suggesting that both may represent reactive phenomena rather than true neoplasms. Our observation prompted us to perform a retrospective review of clear cell acanthoma cases to determine the frequency of such associated eccrine syringofibroadenoma changes. Of 47 examined cases of clear cell acanthoma, 9 (19%) showed associated changes of eccrine syringofibroadenoma. Immunohistochemical evaluation performed on a subset of cases identified similar but slightly divergent differentiation patterns within the lesions. While epithelial membrane antigen and PAS expression were similar in both components (although slightly different in intensity), the regions resembling eccrine syringofibroadenoma displayed additional immunoreactivities, supporting the presence of two distinct components. We have found that the concurrence of clear cell acanthoma with syringofibroadenomatous changes is more frequent than generally appreciated and suggest that these entities may share derivation from the eccrine apparatus.

Receptors of Eccrine, Apocrine, and Holocrine Skin Glands

Skin glands are highly active miniorgans of skin that fulfill a diversity of functions. To coordinate metabolic and secretory activity, they express specific receptors. Recent investigations reveal expression of nuclear hormone receptors, neuropeptide receptors, cytokine receptors, and receptors for peptides of the transforming growth factor superfamily. There is evidence of not only central control, but also autocrine mechanisms of skin glands activity. The knowledge of ligand receptor interactions in these specialized skin structures might offer not only a better understanding of their pathology, but also new therapeutic options.