Chondromyxoid fibroma of sphenoid sinus with unusual calcifications: case report with literature review

Abstract

Chondromyxoid fibroma (CMF) is a rare benign primary tumor which usually affects the metaphyses of the long bone of the lower extremities in childhood and young adults. Rarely, CMF occurs in the skull base and parasinuses, which may be difficult to distinguish from chondrosarcoma or chordoma and other tumors in the head. It is composed of chondroid, myxoid, and fibrous tissue growth in a lobular pattern, infrequently with calcifications. We report one case of CMF involving the sphenoid sinus mimicking a chondrosarcoma. The tumor mass showed calcifications on images and histology.

Keywords: Calcification; Chondromyxoid fibroma; Sphenoid sinus.

Fig. 1

A non-contrast CT scan of the paranasal sinuses showing a heterogeneous mass with fine calcifications, involving the left sphenoid sinus. The mass partially eroded the floor of the sphenoid sinus and protruded into the left nasal cavity (arrow)

Fig. 2

Low magnification of tumor mass shows a well circumscribed cartilaginous neoplasm, with lobular border and peripheral hypercellularity (arrowheads) (a). Section shows the tumor (arrowheads) is adjacent to the sphenoid cavity lined by sinonasal mucosa (arrow), with calcification on the left side (b). High magnification shows tumor is composed of chondromyxoid matrix with stellate fibromyoblastic cells and calcifications (c)

Fig. 3

Immunostains show tumor cells were positive for vimentin (a) and smooth muscle actin (b)