Two Cases of Lower Abdominal Tumors Difficult to Differentiate From Urachal Tumors

Abstract

A 71-year-old man complaining of swelling of the lower abdomen was referred to our department because he was suspected to have a urachal tumor, of about 15 cm in diameter, on computed tomography. A hard infant head-sized mass was palpable in the lower abdomen. Urinary analysis was normal. Cystoscopical examination showed a markedly compressed bladder dome, however, no abnormal findings were seen in the mucosa. Although the preoperative diagnosis was a urachal tumor, the intraoperative pathological diagnosis revealed no malignancy. The mass was connected to the bladder dome, and partial cystectomy was conducted. The final pathological diagnosis was a solitary fibrous tumor. No recurrence has been seen for 5 years postoperatively. Because a urachal tumor is highly malignant, radical cystectomy and urinary diversion might be planned preoperatively. However, care should be taken not to be too invasive, considering the possibility of a benign tumor.

Biomarkers in Urachal Cancer and Adenocarcinomas in the Bladder: A Comprehensive Review Supplemented by Own Data

“…In addition to malignant urachal tumors, several other intermediate and benign tumors or conditions of the urachus have been reported some mimicking urachal cancer and thus posing a differential diagnostic problem. Tumors or conditions rated as intermediate include inflammatory myofibroblastic tumors (IMT) [ 297 – 300 ], a solitary fibrous tumor (SFT) [ 301 ], desmoid fibromatoses [ 302 , 303 ], a hemangiopericytoma [ 304 ], and a Castleman's disease [ 305 ], while benign tumors and conditions include dermoid cysts [ 301 , 306 ], teratomas [ 307 , 308 ], leiomyomas [ 309 , 310 ], (fibrous) hamartomas [ 311 , 312 ], a hemangioma [ 313 ], a fibroadenoma [ 314 ], malakoplakia [ 315 ], abscesses [ 316 – 318 ], a xanthogranulomatous urachitis [ 319 ], a urachal tuberculosis [ 320 ], actinomycosis [ 321 – 323 ], an endometriosis [ 324 ], a perforated colonic diverticulitis [ 325 ], and even a fishbone within an urachal cyst [ 326 ].…”

A case of mucosal‐associated lymphoid tissue lymphoma of the urachus

“…The report concluded that an accurate preoperative diagnosis was difficult. 8 To the best of our knowledge, this is the first reported case of urachal MALT lymphoma. MALT lymphoma is a subtype of extranodal lymphoma associated with a chronic immune response to bacteria, viruses, or the autoimmune system.…”

“…Therefore, under clinical suspicion of localized urachal carcinoma, tumor removal is acceptable, even without pathological confirmation. The previous report showed that two rare tumors arose in the urachus, namely a desmoid and a solitary fibrous tumor 8 . The preoperative diagnosis for both tumors was urachal carcinoma, and frozen sections of the intraoperative biopsy revealed no malignancy.…”

“…The previous report showed that two rare tumors arose in the urachus, namely a desmoid and a solitary fibrous tumor. 8 The preoperative diagnosis for both tumors was urachal carcinoma, and frozen sections of the intraoperative biopsy revealed no malignancy. The report concluded that an accurate preoperative diagnosis was difficult.…”

“…The preoperative diagnosis for both tumors was urachal carcinoma, and frozen sections of the intraoperative biopsy revealed no malignancy. The report concluded that an accurate preoperative diagnosis was difficult 8 …”