Findings: Mammogram: Spiculated mass is identified in the upper outer quadrant of the left breast with associated architectural distortion corresponding to palpable abnormality.

Pathology: Gross Specimen: 2.5 cm. white, dense fibrous mass.

Diagnosis: Granular cell tumor of the breast.

Discussion: The current evidence suggests granular cell tumors are of neural origin from Schwann cells. "6% of granular cell tumors occur in the breast"1. Other sites include tongue, skin, and bronchial wall. Histologically, cells show abundant granular eosinophilic cytoplasm and small round nuclei. Mitosis and pleomorphism are not seen. The positive S-100 protein immunohistochemical stain suggests the neural origin.

Clinically and mammographically, these tumors can simulate carcinoma. Firm, fixed mass with overlying skin changes can be seen. Mammographically, stellate mass with spiculated margins and dense core is often seen. Calcifications are not seen.

Only microscopic evaluation and imminunohistochemical stains reveal the diagnosis.

"Only a few of these tumors have been reported malignant"2. Most are benign and cured by local excision.

References:
1. Basset & Cove: Myoblastoma of the Breast. AJR Jan 1979 pp 122-123.

2. Sendel & Burchett: Case Report: Granular Cell Tumor of the Breast. Clinical Radiology,
1992, 45:347-348.

3. Mariscal, Perea, Castella, Rull: Granular Cell Tumor of the Breast in the Male Patient.
AJR 1995, 165:63-64.

Return to Women's Diagnosic Imaging Page