# Clinical, Radiological, and Pathological Features of Intraosseous Hibernoma: A Systematic Review of Case Reports and Case Series

## TL;DR

This review summarizes 62 cases of intraosseous hibernoma, a rare benign bone tumor that often mimics cancer, to improve diagnosis and avoid unnecessary treatments.

## Contribution

The study provides a comprehensive synthesis of clinical, radiological, and pathological features of intraosseous hibernoma from case reports and series.

## Key findings

- Intraosseous hibernoma commonly appears in the pelvis and spine and is often discovered incidentally during cancer staging.
- Radiologically, it typically shows as a sclerotic lesion with variable PET/CT uptake and is confirmed by S100-positive histology.
- Conservative management after biopsy is effective, with no reported cases of malignant transformation.

## Abstract

Intraosseous hibernoma (IOH) is a rare benign tumor composed of brown fat within the bone. Its unusual imaging features often mimic metastatic disease or primary bone tumors, leading to unnecessary investigations or treatments. This systematic review synthesized all published case reports and case series to clarify its clinical, radiological, histopathological, and management characteristics. We identified 62 confirmed cases from 30 publications. Most lesions were found incidentally, commonly during cancer staging, with the pelvis and spine as the most frequent sites. Radiologically, IOH typically appears as a solitary sclerotic lesion with variable PET/CT uptake, while histology reveals brown adipose tissue with strong S100 positivity. Nearly all patients were managed conservatively following biopsy. Recognizing IOH as a benign mimicker is essential to avoid misdiagnosis and overtreatment, thereby improving patient care.

Intraosseous hibernoma (IOH) is a rare benign tumor composed of brown adipose tissue within the bone, frequently mimicking metastatic lesions and leading to diagnostic challenges. This systematic review aimed to consolidate and analyze all published IOH cases to improve recognition and inform management. A comprehensive literature search was conducted in PubMed, Web of Science, Scopus, Google Scholar, and the Cochrane Library from database inception to March 2025. Studies were eligible for inclusion if they reported histopathologically confirmed cases of intraosseous hibernoma (IOH) in human patients. A total of 62 cases from 30 studies were included. The mean age was 59.2 years, with a female predominance. Lesions were most frequently located in the pelvis and spine and were typically identified incidentally during cancer staging or imaging performed for unrelated indications. Imaging often revealed sclerotic patterns on computed tomography (CT), hyperintense signals on magnetic resonance imaging (MRI) T2-weighted and short tau inversion recovery (STIR) sequences, and mild to moderate uptake on 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT). Immunohistochemistry consistently showed S100 protein positivity. Most patients underwent biopsy and were managed conservatively, with no cases of malignant transformation reported. IOH is a benign entity with distinctive radiologic and immunohistochemical features that may mimic malignancy. Awareness of its presentation can reduce misdiagnosis and unnecessary interventions, supporting biopsy-based confirmation and conservative management in most cases.