Mixed tubulopapillary hidradenoma and syringocystadenoma papilliferum occurring as a verrucous tumor

Tubulopapillary hidradenoma (TPH)(1) is a term proposed to describe morphological dermal ductal tumors with both eccrine and apocrine differentiation. The term TPH encompasses a spectrum of lesions that includes tubular apocrine adenoma (TAA) and papillary eccrine adenoma (PEA):(2) PEA and TAA can be indistinguishable both clinically and histologically. We described a case of TPH with both prominent eccrine and apocrine differentiation combined with syringocystadenoma papilliferum (SCAP) over the distal extremity. This rarely encountered dermatopathological phenomenon is the sixth reported case from the literature in which PEA or TAA and SCAP were present in the same lesion.(3-7) Furthermore, the tumor had a warty surface, which is histologically consistent with a typical viral verruca. Although PCR and DNA probe hybridization for human papilloma virus (HPV) types 2, 6/11, 16 and 18 failed to reveal positive results, the location and clinicopathologic correlation convinced us that superimposed HPV could not be excluded.