# Rare Inflammatory Myofibroblastic Tumor of the Urinary Bladder: A Case Report and Review of the Literature

**Authors:** Zilvinas Venclovas, Agne Talackaite, Gabija Dadurkaite, Stasys Auskalnis, Mindaugas Jievaltas, Ieva Rubaviciute, Daimantas Milonas

PMC · DOI: 10.3390/jcm15052047 · 2026-03-07

## TL;DR

A rare bladder tumor called inflammatory myofibroblastic tumor was diagnosed and successfully treated in a young woman, highlighting the importance of early detection and proper treatment.

## Contribution

This case report adds to the limited literature on rare inflammatory myofibroblastic tumors of the urinary bladder and emphasizes diagnostic and treatment approaches.

## Key findings

- A 32-year-old female was diagnosed with a rare bladder tumor after initial misdiagnosis as cystitis.
- Transurethral resection of the tumor was successful, with no recurrence observed over 30 months of follow-up.
- ALK inhibitors may offer additional treatment options for select cases of this rare tumor.

## Abstract

Background: An inflammatory myofibroblastic tumor (IMT) is a rare mesenchymal tumor, sometimes with urinary bladder involvement (though this is extremely uncommon). Due to its rarity, the exact etiology and optimal treatment strategy remain unclear. Methods: A review of the existing literature on IMT of the urinary bladder was performed. Results: We report a case of a 32-year-old female presenting with frequent urination, hematuria with clots, and lower abdominal pain for one month. Initially misdiagnosed as acute cystitis, the symptoms persisted despite antibiotic therapy. Laboratory findings revealed severe anemia, and imaging studies identified a large bladder mass. Transurethral resection of the bladder tumor (TURB) was performed, and a 96 g mass was removed. Histopathological examination confirmed IMT of the urinary bladder (IMTUB) with positive immunohistochemical staining for ALK, vimentin, and actin. Follow-up at 30 months showed no recurrence, with annual cystoscopy and CT scans confirming remission. Conclusions: IMTUB should be considered in young patients presenting with hematuria and lower urinary tract symptoms. Early diagnosis through cystoscopy, imaging, and histopathological confirmation is essential for appropriate management. TURB remains the gold standard for treatment, with ALK inhibitors providing additional therapeutic options in select cases. Long-term follow-up is necessary due to the unknown malignant potential of IMTUB.

## Linked entities

- **Proteins:** ALK (ALK receptor tyrosine kinase), PRELID1 (PRELI domain containing 1), ACTIN (hypothetical protein)
- **Diseases:** inflammatory myofibroblastic tumor (MONDO:0015798), acute cystitis (MONDO:0001650), anemia (MONDO:0002280)

## Full-text entities

- **Genes:** ALK (ALK receptor tyrosine kinase) [NCBI Gene 238] {aka ALK1, CD246, NBLST3}, VIM (vimentin) [NCBI Gene 7431]
- **Diseases:** IMT of the urinary bladder (MESH:D001749), anemia (MESH:D000740), acute cystitis (MESH:D000208), abdominal pain (MESH:D015746), hematuria (MESH:D006417), Urinary Bladder (MESH:D001745), IMT (MESH:D009369), mesenchymal tumor (MESH:C535700)
- **Species:** Homo sapiens (human, species) [taxon 9606]

## Figures

2 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12986090/full.md

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Source: https://tomesphere.com/paper/PMC12986090