A red nodule in the umbilicus of an older man

This case report describes an interesting example of a syringocystadenoma papilliferum lesion presenting in a 72-year-old man. He presented with a 10-month history of a red nodule in his umbilicus with unexplained weight loss and reduced appetite. The patient had a background of chronic obstructive pulmonary disease, treated prostate cancer and pemphigus vulgaris that had previously been treated with azathioprine. The nodule would occasionally bleed with trauma, but there were otherwise no associated symptoms. Physical examination revealed a 12 × 12 mm firm red nodule within the umbilicus with some creamy exudate overlying it. Given the clinical presentation, differentials at the time included Sister Mary Joseph nodule, amelanotic melanoma and pyogenic granuloma. A shave biopsy was arranged to help diagnose the nodule and further investigations including computed tomography (CT) and colonoscopy were undertaken. CT and colonoscopy did not indicate any sinister pathology. Histopathological findings demonstrated mildly cystic invaginations arising from a papillomatous epidermis that were lined by rows of cuboidal-to-columnar epithelial cells, with oval nuclei and a pale eosinophilic cytoplasm with squamous metaplasia. The stroma contained a dense mononuclear infiltrate, which was comprised predominantly of plasma cells and lymphocytes. The histopathological findings were of syringocystadenoma papilliferum. This report discusses the clinical and histopathologicial presentation of syringocystadenoma papilliferum and the investigations and management to consider with this diagnosis. We also discuss the various differentials that should be considered for a red nodule in the umbilicus.