Pedunculated Polypoidal Anal Canal Lymphangioma in an Adult Male: A Report of a Rare Case and Review of the Literature

Lymphangiomas are benign malformations of the lymphatic system and are often misdiagnosed due to relatively vague and nonspecific symptoms. They most commonly involve the mucous membranes and skin of the head and neck region in pediatric patients. Gastrointestinal tract and anal canal involvement are exceedingly rare, with very limited cases reported in the literature. An adult male in his early twenties presented with complaints of a bloating sensation in his abdomen. Routine investigations were performed. Colonoscopy revealed a solitary, small, pedunculated, polypoid lesion at the 9 o’clock position. Complete excision of the lesion was performed and sent for histopathological examination (HPE), which showed numerous thin-walled, dilated, multicystic cavernous lymphatic channels. On immunohistochemical examination (IHC), the spaces were lined by flattened endothelial cells stained by D2-40 and CD31. Anal canal lymphangiomas are rare, especially in adults. Previously reported cases involved patients aged 32-69 years, making our case among the youngest described, in their early twenties. Unlike common presentations of rectal bleeding or discomfort, our patient reported a bloating sensation. Colonoscopy revealed a polypoidal lesion at the 9 o’clock position of the anal canal. The diagnosis of anal lymphangioma was established and confirmed by IHC with D2-40 and CD31. This case represents the spectrum of age and symptoms of anal lymphangiomas and highlights the need to consider them as an important differential in young adults when dealing with anal canal polyps. Complete excision remains curative with excellent outcomes. This case underscores the need to consider lymphangioma in the differential diagnosis of perianal masses and highlights the pivotal role of histopathology along with immunohistochemical analysis in establishing an accurate diagnosis, which is necessary for formulating appropriate management.