Linear Syringocystadenoma Papilliferum: A Case Report with Review of Literature
A 10-year-old girl presented with multiple asymptomatic papules over right lower abdomen present since the age of 2 months. The lesions were gradually progressive with a rapid enlargement in the last 1 year. There was no history of any neurological, ocular or skeletal abnormality. On examination there were multiple erythematous papules and coalescent plaques (0.5 cm to 5 cm) in a linear pattern over the right lower abdomen []. Most papules were discrete, pink, dome shaped with a few papules showing central umblication and crusting. The papules coalesced to form numerous papillomatous plaques of varying sizes (1 to 5 cm). Yellowish slough and crusting was seen on some of the lesions. The discharge from the lesions foul smelt. No regional lymphadenopathy was present. The routine hematological and biochemical tests, chest radiograph and abdominal ultrasonography were normal.\nThe skin biopsy revealed cystic invagination of epidermis with papillary projection lined by two rows of cells. There were columnar cells towards the lumen and cuboidal cells in the outer layer. Decapitation was seen in the luminal columnar cell layer. The fibrovascular core of papillae showed mixed inflammatory infiltrate comprising of plasma cells, lymphocytes and neutrophils. The underlying deep dermis showed apocrine sweat glands []. The histopathologic features were consistent with the diagnosis of syringocystadenoma papilliferum. Immunohistochemistry (IHC) staining using epithelial membrane antigen (EMA), CD56, CK 19, CK 5, P 63 and smooth muscle antigen (SMA) revealed EMA positivity in columnar cells. Focal positivity of CD 56 was seen in columnar cells. CK 19 was positive in both columnar and basal cells. CK 5 and p63 were positive in basal cells. SMA was focally positive in basal cells []. These findings were consistent with the diagnosis of SCAP of apocrine origin. There was no evidence of malignant transformation. The patient was referred to Plastic surgery for surgical excision with skin grafting. However, the patient was lost to follow up.