Malignant Glomus Tumor: A Case Report and Review of the Literature

Abstract

This report concerns a malignant glomus tumor, a rare soft tissue tumor that was examined immunohistochemically and ultrastructurally. It occurred in a 44-year-old male patient who had suffered from dull pain and stiffness in the right thigh for 10 months. Radiographic examination revealed a well-defined osteolytic lesion in the diaphysis of the right femur. Hypervascularity of the tumor was observed angiographically. Computed tomographic and magnetic resonance examinations showed an intramuscular mass invading the marrow space of the femur. Wide resection was performed after open biopsy. Histologically, round to polygonal tumor cells revealed a uniform appearance of round to ovoid nuclei with single large nucleoli and slightly eosinophilic cytoplasm, forming solid sheets of cells interrupted by vessels of varying size. A few mitotic figures and vascular invasion were observed. Immunohistochemically, vimentin and alpha-smooth muscle actin were stained intensely, and muscle actin was positive for tumor cells of the perivascular area. Tumor cells were negative for desmin, factor VIII-related antigen, S-100 protein, neurofilament, cytokeratin, and epithelial membrane antigen. Ultrastructurally, tumor cells were characterized by many cytoplasmic processes, pinocytotic vesicles, plasmalemmal dense plaques, and scattered microfilaments in the cytoplasm. Few cell junctions and focal basement membrane-like structures were observed. No recurrence or metastasis was noted 57 months after operation. This case was considered to be a malignant glomus tumor, that is, a glomangiosarcoma arising de novo.

Sellar Glomangioma

“…Although glomus tumors are predominantly benign lesions, they occasionally may show atypical features including infiltrative growth pattern or multicentricity [11][12][13]. A small number of cases of glomus tumor have been reported as histologically malignant on the basis of morphological features including nuclear atypia, necrosis, and mitotic activity [11,14,15]. Only a few examples of metastatic disease have been described, and none of these involve sellar glomus tumors [14,16].…”

A Rare Case of Bronchial Glomus Tumor

“…Masson [18]suggested that this tumor represented a hyperplasia or overgrowth of the glomus body. Glomus tumors are therefore usually benign, although malignant cases are occasionally reported [19, 20]. …”

Tracheal Glomus Tumor: A Multidisciplinary Approach to Management

“…27 Glomus tumors are further classified into 3 categories, with regard to the proportions of glomus cells, vessels, and smooth-muscle components: the Glomus tumor proper type, with the round glomus cells representing the largest component; the glomangioma type, where vessels are predominantly present; and glomangiomyoma, where spindle cells are the predominant cell type. 29,30 An oncocytic type, where the tumor cells are characterized ultrastructurally by numerous closely packed round or ovoid mitochondria, has also been described. 13 The histologic criteria of malignancy in glomus tumors are deep location, size Ͼ 2 cm, presence of atypical mitotic figures, or a combination of moderate to high nuclear grade and Ն 5 mitotic figures per 50 high-power field.…”