Low-grade myofibroblastic sarcoma of the liver misdiagnosed as cystadenoma: A case report

Abstract

Background: Low-grade myofibroblastic sarcoma (LGMS) is a rare malignant tumor. It has no specific clinical manifestations and commonly occurs in the head and neck, extremities and other body parts, with the liver not as its predisposing site.

Case summary: We report a case report of a 58-year-old man with right upper abdominal pain for 11 d. Contrast-enhanced computed tomography (CECT), CE magnetic resonance imaging and CE ultrasound (US) all showed a cystic-solid mass in the right liver. As the initial clinical diagnosis was hepatic cystadenoma, surgical resection was performed, and the postoperative pathology indicated hepatic LGMS. The 3-mo follow-up showed favorable recovery of the patient. However, at 7-mo follow-up, two-dimensional US and CECT showed a suspected metastatic lesion in the right-middle abdomen.

Conclusion: Hepatic MS is particularly rare and easily misdiagnosed, more cases will contribute to the understanding and the diagnosis accuracy.

Keywords: Case report; Cystic-solid mass; Diagnosis; Imaging; Liver; Myofibroblastic sarcoma.

Figure 1

Abdominal contrast-enhanced computed tomography and hepatic vascular imaging examination, and magnetic resonance imaging examination. A: The right hepatic cystic-solid mass was supplied by the right hepatic artery, and the twisting of the supplying artery was seen; B and C: The portal phase and delayed phase, respectively; the solid portion and the septum were enhanced, and the intracapsular septum was clearly displayed; D and E: The lesions were low signal on T1-weighted imaging and high signal on T2-weighted imaging, with multiple septa of uneven thickness and fluid-fluid levels; F: After enhancement, the solid components and septa of the mass were significantly enhanced, but the cystic components were not.

Figure 2

Contrast-enhanced ultrasound examination. The peripheral parenchyma and internal septa of the mixed-echo mass showed hyper-enhancement in the arterial phase, and iso-enhancement in the portal and delayed phases. A: Arterial phase; B: Early portal phase; C: Late portal phase; D: Delayed phase.

Figure 3

Gross pathology specimen and pathological microscopy. A: A cystic-solid mass was seen with the naked eye, with soft texture and inconspicuous tumor capsule; its cut surface was polycystic, with yellowish jelly-like substances inside the cysts, and the cyst wall thickness was 1 mm-12 mm; no cirrhotic changes were observed in the peripheral liver tissue (arrow); B and C: Spindle-shaped cells are arranged in fascicles under light microscope, eosinophilic cytoplasm with atypia and mitotic figures were seen.

Figure 4

Abdominal contrast-enhanced computed tomography examination at 7-mo follow-up. A and B: The right middle abdomen of the patient in contrast-enhanced computed tomography showed a cystic-solid lesion, with the similar property as a liver lesion. After enhancement, the mass wall was enhanced.