Intrathoracic hibernoma: Report of two cases

Hibernoma: Intense Uptake on F18-FDG PET/CT

“…The CT, MRI, ultrasonography, angiography, and F18-FDG PET imaging of hibernomas reflect their histopathology and the relative amount of brown fat and white fat [1,[7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]. The masses are often heterogenous on MRI and CT with characteristics similar but not identical to those of fat.…”

“…In our case, a linear hyperintensity entering the enhancing back mass in a contrast-enhanced MRI may be a supplying vessel that was not confirmed by angiography. Hibernomas usually demonstrate intense F18-FDG accumulation [1,7,[13][14][15][16][17][18], which has been attributed to the high rate of metabolism of these tumors as precursors of brown fat and should not be regarded as evidence of a malignancy. Hibernomas have been detected incidentally on technetium-99m tetrofosmin myocardial perfusion studies performed in patients with chest pain, appearing as mass-like areas of increased uptake [16,22].…”

“…Core needle biopsy has not been recommended in cases of suspected hibernoma due to the tumor's hypervasculariy [7,21]. The treatment consists of complete surgical resection and the postoperative prognosis is excellent [1,4,14,23].…”

Functional Diagnosis of Hibernoma by FDG Imaging Under Propranolol Treatment: A Case Report

“…Its diagnostic definition is hampered by the lack of morphologic criteria able to accurately differentiate this rare incidental from other malignant lesions such as liposarcoma, rhabdomyosarcoma, giant cell tumor and lymphoma [6,[10][11][12]. A similar misdiagnosis can occur at PET/CT imaging since the high FDG intake can reflect either a Warburg effect of a rapidly proliferating high-grade mesenchimal tumors and a high glycolytic flux caused by adrenergic activation of brown fat to preserve body temperature under cold exposure.…”

“…The lesion displayed only mild mass effect on the surrounding structures ( Figure 1B-C). CT-guided biopsy was then attempted but did not provided adequate specimen [6].…”