Syringocystadenoma papilliferum is a rare adnexal tumor that often occurs as a solitary tumor in the head and neck region, although occurrences on other anatomical locations have been described. Linear configurations have been described, but an agminated form is a more rare and underreported variant of this tumor. We describe a case of a healthy 10-year old female with agminated syringocystadenoma papilliferum occurring on her left supraclavicular region, with the clinical appearance of grouped molluscum contagiosum papules.Case synopsis

A healthy 10-year-old girl was referred for the treatment of a "collection of molluscum contagiosum" of the left supra clavicular region of several years duration. The lesions were asymptomatic and refractory to cryotherapy. The patient was a healthy girl with no significant systemic findings. Cutaneous exam revealed a clustered group of pink, dome shaped, umbilicated papules over a 1.5 x 1 cm area within the left supraclavicular fossa (Figure 1a).

An excisional biopsy was performed. Routine H&E stained sections revealed cystic epidermal invaginations with papillary projections. The superficial portions of the cyst were lined by stratified keratinizing epithelium, whereas the deeper papillated portion exhibited a double layer of basal-like cells and luminal eosinophilic columnar cells with focal decapitation secretion. The papillary structures contained fibrovascular cores and lymphoplasmacytic infiltrates. A component of hamartomatous follicular growth was not identified (Figure 1b-d.).  A diagnosis was made of agminated syringocystadenoma papilliferum.

Benign melanocytic nevi are slowly growing acquiredor congenital tumors with varied morphology,commonly encountered in dermatology clinics. Anytumor with rapid clinical growth must be assessedcarefully in order to exclude malignancy. We report awoman with a histopathologically benign intradermalnevus that presented as a rapidly evolving largecutaneous mass on the ear. Owing to the discrepancybetween the clinical and histopathological findings,an extensive histopathological work-up involvingmany deeper sections, immunohistochemical stains,and fluorescent in situ hybridization (FISH) analysiswas conducted in order to rule out malignancy.