Rationale: Inflammatory myofibroblastic tumor (IMT) is a rare soft tissue lesion, originally reported in the lungs. Occurrence of the IMT was also documented in the digestive system, but rare in the urinary system, especially in the urachus, and little is presently known about IMT.
Patient concerns: This study reported a very rare case of urachal IMT in an elderly female patient at the age of 77 who was diagnosed with a lower abdominal mass 2 months ago.
Diagnosis: The preoperative diagnosis was urachal carcinoma, which was confirmed to be anaplastic lymphoma kinase (ALK) negative urachal IMT by postoperative histopathology and immunohistochemistry tests.
Interventions: Laparoscopic radical urachal carcinoma resection and partial bladder resection was performed under general anesthesia, and the tumor was completely removed.
Outcomes: There was no recurrence and metastasis over 22 months of follow-up.
Lessons: The urachal IMT occurs mainly in males and nonelderly people with ALK positive while in females with ALK negative. The most common clinical manifestations of urachal IMT are lower abdominal masses; it is very important to distinguish whether the tumor originates from the bladder or the urachus, because the surgical treatment options are completely different. Currently the complete surgical removal of the tumor is the best treatment option for urachal IMT. No other adjuvant therapy is required after operation. All urachal IMT after follow-up showed no recurrence and metastasis, suggesting a good prognosis. However, IMT has malignant potential and it requires a long-term close follow-up check.