Unusual paediatric sigmoid perivascular epithelioid cell tumour with regional lymph node metastasis treated using gemcitabine and docetaxel: a case report and literature review

Abstract

Perivascular epithelioid cell tumour (PEComa) is an extremely rare neoplasm with distinctive morphology and specific expression of immunohistochemical markers. The lesion is typically diagnosed in middle-aged women, with few reports of paediatric cases, and there is no standardized treatment for the tumour type. Here, the case of a 17-year-old female, who presented with painless haematochezia for 2 days and was diagnosed with gastrointestinal PEComa of the sigmoid colon with regional lymph node metastasis after serial examination, is presented. She was treated by surgical resection of the tumour and cytotoxic chemotherapy comprising 900 mg/m² gemcitabine and 100 mg/m² docetaxel every 3 weeks for six cycles. Haematochezia did not recur, and complete response was achieved, with progression-free survival at the 24-month follow-up examination. Surgical resection with adjuvant conventional cytotoxic chemotherapy may be considered as an option for treating gastrointestinal PEComa.

Keywords: PEComa; PEComa–not otherwise specified; Perivascular epithelioid cell tumour; case report; early-stage gastrointestinal PEComa; gastrointestinal PEComa; paediatric sigmoid PEComa.

Figure 1.

Representative images from abdominal computed tomography (CT) of the primary tumour in the sigmoid colon, showing a large pedunculated polypoid lesion measuring 3.5 × 3.1 × 2.8 cm, with heterogenous enhancement in the rectosigmoid colon (arrow) and metastatic lymphadenopathy of approximately 0.6 cm in the paracolic region: (a) plain CT axial plane; (b) arterial phase axial plane; (c) sagittal plane; and (d) coronal plane.

Figure 2.

Representative colonofibreoscopy images showing a large submucosal tumour with ulcerations and a large stalk at 10 cm from the anus.

Figure 3.

Representative tissue sections of the primary tumour in the sigmoid colon: (a) haematoxylin and eosin-stained section showing nests and sheets of plump round to polygonal cells with a clear cytoplasm, and large vessels with perivascular growth; and (b) cytoplasmic pigmentation and HMB-45 positive immunostaining of the tumour cells (both original magnification, × 400).