Korean J Urol.  2010 Jun;51(6):438-440.

Urachal Actinomycosis Mimicking a Urachal Tumor

• Lim KT
• Moon SJ
• Kwon JS
• Son YW
• Choi HY
• Choi YY
• Pyo JY
• Park YW
• Moon HS

Abstract

A 26-year-old man presented with lower abdominal discomfort and a palpable mass in the right lower quadrant. An abdominal computed tomography (CT) scan revealed an abdominal wall mass that extended from the dome of the bladder. Fluorine-18 fluorodeoxyglucose (FDG) positron-emission tomography/CT (PET/CT) showed hypermetabolic wall thickening around the bladder dome area that extended to the abdominal wall and hypermetabolic mesenteric infiltration. Differential diagnosis included a urachal tumor with invasion into adjacent organs and chronic inflammatory disease. Partial cystectomy with abdominal wall mass excision was performed, and the final pathologic report was consistent with urachal actinomycosis.

Keyword

Actinomycosis; Positron-emission tomography; Urachal cyst

MeSH Terms

Abdominal Wall
Actinomycosis
Adult
Cystectomy
Diagnosis, Differential
Humans
Positron-Emission Tomography
Urachal Cyst
Urinary Bladder

Figure

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  FIG. 1 Abdominal computed tomography (CT) showing wall thickening and a mass on the bladder dome. The mass extends to the abdominal wall from the bladder dome.

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  FIG. 2 Serial positron-emission tomography/computed tomography (PET/CT) images showing mild hypermetabolic wall thickening in the anterosuperior portion of the bladder (arrow heads) with hypermetabolic mesenteric and omental infiltration (arrows) extending along the urachus (thin arrow).

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  FIG. 3 (A) Partial cystectomy specimen revealing diffuse fibrotic thickening of the wall and relatively preserved luminal surface. There is an irregular necrotic lesion with yellowish foci in the deep resection margin. (B) Bacterial colony in the abscess background showing central entangled filamentous bacteria with a sunray appearance in the peripheral portion (H&E, ×400).

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