Surgical treatment of a congenital rectal cystic hamartoma in a 20-day Kurdish foal.

Hamartomas are mostly benign tumor-like malformations characterized by a disorganized overgrowth of mature cells and tissues indigenous to the affected anatomical site. A 20-day-old male Kurdish foal was presented to the Veterinary Teaching Hospital of Urmia University, Urmia, Iran, with a history of hematochezia and tenesmus. Clinical examination identified a pedunculated tissue mass within the rectal lumen. The abnormal mass was surgically excised via polypectomy under local anesthesia. Tissue samples were obtained, fixed in 10.00% neutral buffered formalin, and processed routinely for histopathological examination. Histopathological evaluation of the resected tissue confirmed the diagnosis of a cystic polypoid rectal hamartoma characterized by normal rectal epithelium overlying multiple cystic, blood-filled vascular spaces. The foal recovered without complications and no recurrence was noted during a long-term follow-up exceeding 18 months. This report underscored that congenital rectal hamartoma, while rare, should be considered as a differential diagnosis in neonatal foals presenting with hematochezia or dyschezia. Prompt surgical intervention is curative and associated with a favorable prognosis.