En bloc resection of pararectal ectopic thyroid tissue: a case report

A pararectal mass’ specific diagnosis can be challenging as a broad range of both benign and malignant tumors are possible. Many of these lesions are congenital and do not require treatment, if asymptomatic. Special attention is to be paid when imaging findings are not typical. In such cases, definitive diagnostic can require surgical excision. To this day, ectopic thyroid tissue was not part of known differential diagnosis. This is the first reported case of thyroid adenoma found in the perirectal area. Ectopic thyroid gland can progress over time and include malignant transformation, although rare. It needs to be considered when managing these cases, especially in unusual locations. This case report offers a systematic approach to the atypical pararectal tumor. It shares new specific clinical experience in managing a case of pararectal ectopic thyroid adenoma, from both a surgical and a histopathological point of view.