Metastatic carcinoma with myxoid stroma in the salivary gland: a case report.

BACKGROUND

Most epithelial salivary gland tumors with a myxoid stroma are pleomorphic adenomas. Rare metastatic carcinomas have prominent myxoid stroma and therefore can mimic pleomorphic adenomas cytologically.

CASE

A 62-year-old man presented with a left canthal tumor. A biopsy and computed tomography revealed an adenocarcinoma of the left ethmoid sinus with medial canthal extension. The patient was treated with tumor resection and chemoradiation. An enlarging, left parotid mass developed that was reported as a pleomorphic adenoma on a fine needle aspirate. However, a parotidectomy showed metastatic adenocarcinoma with a myxoid and fibroblastic stroma in an intraparotid lymph node.

CONCLUSION

Before concluding cytologically that a biphasic epithelial/myxoid stromal salivary gland lesion is a pleomorphic adenoma, the patient's previous malignancies should be reviewed, and the smears should be scrutinizedfor the absence of diffuse epithelial atypia and presence of spindle cells transitional between the 2 tissue phases.