CT, MRI, and FDG-PET imaging findings of low-grade extrauterine endometrial stromal sarcoma arising from the mesentery: A case report

Abstract

Endometrial stromal sarcoma is a rare uterine mesenchymal neoplasm, and extrauterine endometrial stromal sarcoma is even rarer, with a limited number of case reports. In the present report, we present a case of low-grade extrauterine endometrial stromal sarcoma originating from the mesentery in a 49-year-old woman, without endometrial stromal sarcoma in the uterus or evidence of endometriosis. The tumor was diagnosed using recombination of the JAZF1 gene by fluorescence in situ hybridization. Computed tomography, magnetic resonance imaging, and 18F-fluorodeoxyglucose positron emission tomography/computed tomography showed a 13 cm, primarily polycystic, mass containing a contrast-enhancing solid component with restricted diffusion and mild 18F-fluorodeoxyglucose uptake. A large cystic component may be a characteristic feature of extrauterine endometrial stromal sarcoma, given the low pressure from the surrounding tissues.

Keywords: Computed tomography; Extrauterine endometrial stromal sarcoma; Fluorodeoxyglucose-positron emission tomography; JAZF1; Magnetic resonance imaging; Mesentery.

Fig. 1

(A) A 13 cm solid and cystic mass with contrast enhancement (arrow); (B) the mesenteric vein is located at the periphery of the mass (arrowhead)

Fig. 2

The solid part of the mass (arrows) shows heterogeneous signal intensity on axial (A), coronal (B), and sagittal T2-weighted imaging (T2WI) (C), and axial T1-weighted imaging (T1WI) (D); the dorsal edge of the mass is ill-defined; diffusion is restricted in the solid part with apparent diffusion coefficient (ADC) of 1.04 × 10⁻³ mm²/s (E and F)

Fig. 3

18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) shows abnormal FDG uptake in the solid part (arrows); the maximum standardized uptake value (SUVmax) was 4.5 at 1 h after (A) and 5.9 at 2 h after isotope injection (B).

Fig. 4

Operative view of the tumor (arrow) arising from the mesentery (arrowhead)

Fig. 5

Microscopic view of the resected specimen (×100 each); (A) Hematoxylin and eosin (HE) stain shows diffuse proliferation of cells with ovoid- to spindle-like nuclei with a few regions of hemorrhage, edema, and necrosis; immunohistochemical staining with (B) cluster of differentiation 10 (CD10) and (C) ER was positive.