RETRORECTAL CYSTIC TUMORS: CASE REPORT OF A TAILGUT CYST

Woman, 34 years old, under investigation for anemia and menorrhagia. Pelvic magnetic resonance imaging revealed a multiloculated retrorectal cystic lesion, hyperintense on T2-weighted images and hypointense on T1-weighted images, with thickened walls, showing slight enhancement of the wall and septa with contrast. She underwent surgical cystectomy via the Kraske approach, during which the lesion ruptured intraoperatively, resulting in the extrusion of thick, heterogeneous, purulent content. She had a good clinical-surgical recovery and was discharged on the 3rd postoperative day. Histopathology revealed an encapsulated, irregular, multiloculated lesion measuring 6.8 × 4.5 × 3.0 cm, devoid of content and lined with keratinizing and non-keratinizing squamous epithelium. Findings were consistent with a retrorectal cystic hamartoma with areas of rupture, without signs of malignancy. Retrorectal space tumors can originate congenitally, secondary to embryological remnants, or from the degeneration of adjacent anatomical structures. In adults, these tumors are rare and predominantly benign, with a higher prevalence in middle-aged women. Most cases are asymptomatic and diagnosed incidentally, though they can present with rectal pain, hematochezia, infection, fistulization, or malignant degeneration. If infected, they may be misdiagnosed as pilonidal cysts, anorectal fistulas, or recurrent retrorectal abscesses. On computed tomography or magnetic resonance imaging, they appear as well-defined masses with heterogeneous and multilobulated content. Findings of poorly defined margins and local invasion suggest infection or malignancy. Other features indicative of malignant degeneration include wall thickening and the presence of intracystic vegetations. Regarding management, hindgut cysts require complete surgical excision for pathological analysis to confirm the diagnosis and rule out malignant degeneration, which may be focal and not identified by guided biopsy. Differential diagnoses include epidermoid, dermoid, or rectal duplication cysts, mucinous perianal carcinoma, lymphangioma, and cystic teratoma. Retrorectal hamartomas are rare benign lesions, and histopathological evaluation enables diagnosis and exclusion of malignancy. Complete surgical removal is necessary for detailed lesion assessment and to prevent recurrence.

No conflict of interest has been declared by the author(s).

Publication History

Article published online:
25 April 2025