Syringocystadenoma papilliferum is a rare benign adnexal tumor commonly located on the head and neck region and is usually associated with a nevus sebaceous. Linear lesions are uncommon and lesions on the breast are extremely rare. We report here a case of linear SCAP occurring de novo on the left breast of a 35-year-old healthy woman. Histopathology showed the characteristic papillary projections lined by double layer of cells inside epidermal invaginations.

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).

Syringocystadenocarcinoma papilliferum (SCACP) is a rare adenexal carcinoma with only 21 cases reported in the literature. Most patients describe a long-standing mass with recent change, supporting the idea that SCACP arises from malignant transformation of pre-existing syringocystadenoma papilliferum (SCAP). Syringocystadenocarcinoma papilliferum is generally treated with wide surgical excision of the lesion and patients do exceeding well and require no systemic therapy.