A Case of Anorectal Malakoplakia with Ectopic Recurrence in the Inguinal Region

Abstract

The patient was an 80-year-old man who was referred to our hospital because of anal pain with an associated mass in the anus. A 60×25 mm skin mass with induration was found from the anal verge at 12 o'clock to the perineum, and computed tomography (CT) showed a substantial mass with contrast effect. A biopsy showed a collection of histiocytes with Michaelis-Gutmann bodies (MG bodies), and a diagnosis of malakoplakia was made. The margins of the mass were used as the excision line for resection. Seven months after surgery, the patient returned to the hospital with a complaint of a mass in the right inguinal region, and CT showed a substantial mass similar to the previous one in the anorectal region. The mass was found to be self-destructing and draining, and a right inguinal mass excision was performed to confirm the diagnosis and improve the patient's quality of life. Histopathological examination showed numerous MG bodies with positive findings on AB-PAS and iron staining, leading to the diagnosis of recurrent malakoplakia. The occurrence of this disease in the anorectal region itself is rare, and there have been no reports of ectopic recurrence in Japan. A case of anorectal malakoplakia with ectopic recurrence in the inguinal region is reported.