Incidentally detected vesico inguinal hernia on fluoro-deoxy glucose positron emission tomography-computed tomography.

Sir,

Herniation of the urinary bladder is rare and most cases are asymptomatic. They are incidentally noted during imaging or during the course of surgical repair. Though rare, compilations like acute renal failure, rupture, infection and calculus formation can occur. We report a case of vesicoinguinal hernia, detected incidentally on the whole body fluoro-deoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) study.

A 65-year-old man who presented with cervical lymph nodal enlargement was subjected to excision biopsy. Histopathology revealed metastases from poorly differentiated carcinoma. He was referred for a whole body FDG PET-CT study. PET scan [Figure 1] showed elevated FDG uptake in the surgical site. A suspicious soft-tissue nodule was noted near the deep lobe of left parotid gland. Incidentally, there was herniation of the urinary bladder into the right inguinal canal (a) urinary bladder herniation was clearly depicted in the coronal CT (b) and fused PET-CT (c) and the sagittal CT (d) and fused PET-CT (e) images.

Figure 1

F-18 fluoro-deoxy glucose positron emission tomography (PET) scan (a) MIP (maximum intensity projection) image, (b) coronal computed tomography (CT), (c) coronal fused PET/CT (d) sagittal CT and (e) fused sagittal PET/CT images showing herniation of the urinary bladder into the right inguinal canal

Variety of incidental findings have been reported on FDG PET-CT studies. About 1-4% of all inguinal hernias involve the urinary bladder.[1] In aretrospective study of 662 patients with inguinal hernianly 2 patients had vesicoinguinal hernia.[2] Most cases are asymptomatic and are usually found incidentally on radiographic imaging or at the time of herniorrhaphy. Less than 7% of bladder hernias are diagnosed pre-operatively.[3] Only three cases of the urinary bladder herniation detected on FDGPET-CT have been previously reported.[456] Other incidental findings such as rupture[7] and vesico-colic fistula[89] have also been described in FDG PET studies.