Retrorectal Hibernoma: a Rare Tumor with Unusual Presentation

   

Meriem Dehal¹, Karim Haddad¹, Salim Belkherchi², Hadjer Ouahabi¹, Fatiha Berrebiha¹ and Salah Berkane¹

Received: January 12, 2023 | Published: January 30, 2023

Copyright^© 2023 by Dehal M. All rights reserved. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

DOI: https://doi.org/10.52793/JCTR.2023.3(1)-23 

Abstract

Introduction

Hibernoma is a rare tumor that develops from fat cells. It is a benign tumor that grows slowly and rarely gives rise to particularly painful symptoms. The main differential diagnosis is liposarcoma. We report a case of a hibernoma with unusual location (retrorectal with gluteal development). Observation this is a 37-year-old woman with no significant history who presented with swelling of the left buttock that had been evolving for 5 years. The clinical examination revealed a swelling 20cm in large diameter that bulges at the level of the left buttock. This formation was painless, soft in consistency and the skin over it is of normal color and appearance. Digital rectal examination perceived a formation of soft consistency. This patient had no medical or surgical history. Soft in consistency and the skin over it is of normal color and appearance. Digital rectal examination perceived a formation of soft consistency. This patient had no medical or surgical history. A complete surgical resection was with simple post operative course. The histological study revealed a hibernoma. The patient is alive without recurrence at 8 months postoperatively.

Conclusion

This retrorectal localization of the hibernomaisvery rare. This tumor is currently well characterized with modern morphological examinations which allow a fairly precise diagnostic approach. Diagnosis may in some cases require cytopuncture.

Keywords

Hibernoma; Retrorectal location; Bisactumor

Introduction

Retrorectal tumors are a rare entity, often benign, asymptomatic, with a female predilection. They include a wide range of histological differentiation that can be benign or malignant [1]. Here, we report a case of retrorectal gluteal hibernoma, which is a rare benign tumor derived from brown fat, seen in fetuses and hibernating animals. It results in a mass of slow evolution that is not very painful. This type of tumor essentially poses a diagnostic problem with sarcomas.

Observation

This is a 37-year-old patient with no notable pathological history, who consulted for a painless formation of the left buttock. In the anamnesis, the patient specifies that this formation appeared for 5 years and gradually increased in size to reach a dimension of 20cm at present. It began to cause discomfort when the patient puts it in a sitting position. The patient was in good general condition and is a febrile. The clinical examination in the gynecological position and in lateral decubitus showed the following facts: a mass of soft consistency in the left buttock, 20 cm long, non-pulsatile, painless and not very mobile. The skin opposite had a normal appear ance both in its coloration and through its color and its palpation. There were no down stream neurovascular disorders or satellite adenopathies and hip mobility was normal. There was a depression of the inter-gluteal groove (Figure n° 1).

Figure n° 1: Clinical aspect of the tumour on examination.

The digital rectal examination found a normal looking anal margin as well as the tone of the anal sphincter. The finger perceived a formation of soft consistency in left laterorectal. The rectal wall was normal. The rest of the somatic examination was un remarkable. The biological examinations carried out were normal, in particular blood sugar levels, blood urea and creatinine, blood crasis and the inflammatory assessment.

Pelvic ultrasonography (US) showed the existence of an inter-communicating cystic formation of the musculo-aponeurotic soft tissues of the left gluteal region and the posterior root of the under lying thigh. Abdomino pelvic computed tomography (CT Scan) revealed a septate, biloculated, thin-wall edcystic mass. She was enhanced with the injection of the contrast product. It was multi loculated with a component of the fatty plane of the left buttock of 170x70mm and a left perirectal component pushing back the rectum and the vagina of 100x70mm with integrity of the fat opposite (Figure n°2).

Figure n°2: Radiological aspect on CT Scan.

Magnetic resonance imaging (MRI) confirmed the presence of a multi-partitioned biloculated cystic mass delimiting cubicles and showed a bisac shape (Figure 3). It showed two cystic masses, one in the fatty plane of the buttock measuring 177x73 mm and the other extending towards the homo lateral is chio-rectal space of 200*70mm. This latter formation pushed the lower and middle rectum to the left and the vagina to the right without signs of infiltration. She had a persistent hyper signal on T1 on the FAT SAT sequences with lobular contours well limited by a clean wall and a hyper signal on T2, not enhance dafter contrast product (Figures n°3 and n°4).

Figure n°3: Radiological aspect on MRI (T1).