Radiological findings of two neoplasms with perivascular epithelioid cell differentiation

Abstract

Perivascular epithelioid cell tumors (PEComas) constitute a rare subset of mesenchymal neoplasms classified by the World Health Organization in 2002. We present two cases of PEComas; the first is a cervical PEComa in a 35-year-old woman with no known past medical history who presented with a palpable pelvic mass; the second is an adnexal PEComa in a 39-year-old woman with a history of colitis who presented with abdominal pain and diarrhea. The rarity of these tumors has led to little information about imaging characteristics which we hope these two cases will help expand.

Keywords: Epithelioid; Mesenchymal; PEComa; Perivascular.

Fig. 1

(A) Axial T2-weighted image at the level of the pelvis demonstrates a complex cystic mass arising from the anterior wall of the cervix, with internal septations (arrows) of varying thickness. (B) Axial T1-weighted image with fat suppression demonstrates areas of high T1 signal (arrow) within the mass, consistent with hemorrhagic or proteinaceous fluid. (C) and (D) Axial in-phase and out-of-phase images demonstrate absence of microscopic fat within the mass.

Fig. 2

(A) Sagittal T2-weighted image in the same patient again shows the large mass with cystic (arrowhead) and solid (arrow) components arising from the anterior cervical wall. (B) Postcontrast fat-saturated T1-weighted sagittal image demonstrates avid enhancement within the solid component (arrow).

Fig. 3

Sagittal grayscale image of the right adnexa from the transvaginal portion of the study shows a complex mass with solid and cystic components.

Fig. 4

(A) and (B) Contrast-enhanced axial and sagittal CT images show a complex right adnexal mass with cystic (stars) and avidly enhancing solid (arrows) components. Trace free fluid is identified in the pelvis (arrowheads).

Fig. 5

(A) and (B) T2-weighted axial and sagittal images demonstrate a complex right adnexal mass with cystic (arrowheads) and solid (star) components. There is also mild circumferential wall thickening of the rectosigmoid colon (arrow). (C) Small areas of high T1 signal (arrow) within the mass on T1-weighted image with fat saturation represent hemorrhagic or proteinaceous fluid. (D) and (E) Following intravenous contrast administration, fat-saturated T1-weighted axial and sagittal images show avidly enhancing solid components (arrowheads), as well as wall thickening and enhancement of the rectosigmoid colon.