Syringocystadenoma papilliferum on the thigh: An unusual location

Abstract

A 28-year-old man presented with a partially eroded growth on the back of his right thigh for the last 15 years. Tuberculosis verrucosa cutis and pyogenic granuloma were suspected on clinical examination. Histopathological examination revealed syringocystadenoma papilliferum (SCAP). SCAP is rare on the thigh and a review of the English literature revealed eight cases. Non-descript clinical presentation in an unusual location and the rare linear and segmental variants lead to misdiagnosis. Onset at puberty should alert one to the possibility of the unusual location of SCAP.

Syringocystadenoma Papilliferum: An Unusual Presentation

“…Uncommon sites of occurrence which have been reported in the literature include chest, arms, breast, eyelids, axilla, scrotum, thigh, lower legs, toes, inguinal and perineal regions [3][4][5][6]. Ninety percent of the cases show involvement of anatomic sites which are normally devoid of apocrine elements [1]. Nodular variety shows more involvement of the trunk [7].…”

“…Syringocystadeno carcinoma papilliferum can also arise in benign lesions [11]. The commonest association is its occurrence within a naevus sebaceous [1].…”

“…Diastase resistant Periodic acid-Schiff (PAS) positivity favours the apocrine differentiation of this tumour [6]. Tumour cells also may show positivity for carcinoembryonic antigen (CEA) and protein-15 [1]. Clinically, the differential diagnosis which is thought of includes cutaneous tuberculosis and pyogenic granuloma.…”

“…The cells which line the lumina show evidence of a decapitation secretion, thus pointing towards an apocrine origin. Results of enzyme histochemistry, immunohistochemistry and electron microscopy, obtained, have been conflicting [1].…”

“…The treatment for Syringocystadenoma papilliferum is excision biopsy, which also confirms the diagnosis [1,11]. Carbon dioxide lasers have gained importance for treatment of lesions at difficult anatomic sites, which were not suitable for surgery [12].…”