Pure Uterine Lipoma on 18FDG PET/CT: Rare But Easy to Diagnose

Abstract

Tumors of the uterus are extremely uncommon. Pure lipomas of the uterus are very rare, and only a few cases have been reported. We are presenting a case of a post-menopausal lady, a survivor of right breast cancer who had an 18 F-fluorodeoxyglucose positron emission tomography/computed tomography ( 18 FDG PET/CT) for evaluation of a suspected right lung nodule. The scan was negative for hypermetabolic abnormality. However, a hypodense and non-metabolic lesion was seen in the fundus of the uterus. On subsequent hysterectomy, it was found to be a pure lipoma.

Lipoleiomyomas of the Uterine Cervix: A New Series including the First Recurrent Case and the First Systematic Literature Review

“…Pure malignant or benign lipomatous tumors (liposarcomas or lipomas) or other rare mesenchymal tumors with occasional foci of adipocytic differentiation (such as solitary fibrous tumors) also enter the differential diagnosis with LLMs; they are usually reported in the uterine body, exceptionally occurring in the cervix [14,[45][46][47][48][49][50][51][52]. Lipomas are entirely composed of fat tissue, while liposarcomas show malignant histological features that were absent in our series.…”

“…Lipomas are entirely composed of fat tissue, while liposarcomas show malignant histological features that were absent in our series. Solitary fibrous tumors have a haphazard arrangement of spindled to ovoid cells arranged around branching and dilated vasculature within a variably collagenous stroma; desmin is expressed by a subset of cases while STAT6 positivity is typical [14,[45][46][47][48][49][50][51][52].…”

A Large Pure Uterine Lipoma: Its Diagnosis by Pelvic MRI and Histopathology

“…A lipoma of the uterus would appear with high signal on T1 and T2 sequences and show a signal dropout on fat suppression sequences [5]. On ultrasound, these tumors appear as well-defined hyperechoic lesions because of the fat and are avascular with a hypoechoic rim due to the myometrium in the periphery [2]. Due to the tumor location and size, our patient was first suspected to have an ovarian tumor with a thick wall near the uterus.…”

“…Lipomatous tumors of the uterus are very rare and have an estimated incidence of approximately 0.03 to 0.2% [1]. Mixed-type fatty tumors containing different amounts of smooth muscle and fibrous tissue have been the most frequent type reported; however, pure lipomas of the uterus are extremely rare [2]. Since only a few cases have been reported, the exact incidence is still not known.…”

“…Malignant conversion of these tumors is rare. Given these characteristics, they are usually diagnosed incidentally [4,6]; however, they can sometimes present with nonspecific symptoms such as abdominal pain and/or vaginal bleeding [2,7]. Uterine lipomas are commonly found in the body of the uterus and measure approximately 5-10 cm in size [3,5,8].…”