A verrucous tumor of the leg: Atypical case of Syringocystadenoma Papilliferum.

Syringocystadenoma Papilliferum (SCAP) is a benign adnexal tumor. Most of the cases present with a solitary lesion in the head and neck region at birth or in early childhood. In fact, only two cases of SCAP on the lower leg have been reported in the literature. We report an atypical case by its location and its clinical aspect.

A 56‐year‐old woman, with no medical history, presented with a nodular lesion of the left leg, of 2‐year duration. Physical examination revealed a warty mass with a keratotic surface measured 2 cm (Figure 1). A surgical excision was performed. Histology showed hyperkeratosis, parakeratosis, papillomatosis, and cystic invaginations extending downward from the epidermis. Two different epithelial cell layers consisting of outer small cuboidal cells and inner columnar cells were present. The papillary projections and dermis had also dense infiltration of plasma cells (Figure 2).

FIGURE 1

A warty mass with a keratotic surface measured 2 cm on the left leg

FIGURE 2

Proliferation of papillary and tubular structures bordered by significant epidermal hyperplasia forming lateral beaks (A, HE × 25) (B, HE × 100). The papillae are lined with a bistratified epithelium without atypia and their axes are very rich in plasmocytes (C, HE × 25) (D, HE × 200)

Based on these findings, a diagnosis of Syringocystadenoma Papilliferum (SCAP) of the leg was established.

Syringocystadenoma Papilliferum is a benign adnexal tumor. It mainly occurs in the head and neck region at birth or in early childhood. In fact, only two cases of SCAP on the lower leg have been reported in the literature. The differential diagnosis of any long‐standing nodular lesion with crusted surface has to be considered such as verruca vulgaris, verrucous carcinoma, tuberculosis verrucosa cutis, hypertrophic lichen planus, and pyoderma vegetans. Histogenesis of SCAP remains controversial. Histopathologically, there is no difference between SCAP on different locations. Immunohistopathology may help in favoring eccrine or apocrine lineage but is not required for diagnosis. Surgical excision is curative.

AUTHOR CONTRIBUTIONS

Dr chaima kouki and sellami khadija, wrote the manuscript and is the guarantor of the content of the manuscript, included the data and analysis. Dr masmoudi Abderrahman and Kammoun Nadine to analysis and interpretation of data, revised it critically. Dr Saguem ines provided the anatomopathological figures. Dr Hamida Tuki and Dr Boudawara tahya contributed to the final approval of the version of the manuscript to be submitted.

CONFLICT OF INTEREST

None.

ETHICAL APPROVAL

Approved.

CONSENT

Approved by all authors. Written informed consent was also obtained from the patient to publish this report in accordance with the journal’ patient consent policy.