SALIVARY DUCT CARCINOMA .1. A CLINICOPATHOLOGICAL EVALUATION AND DNA IMAGE-ANALYSIS OF 13 CASES WITH REVIEW OF THE LITERATURE

Salivary duct carcinoma is an uncommon and relatively unknown clinical ly aggressive adenocarcinoma of salivary origin that histologically de monstrates a remarkable resemblance to invasive carcinoma of the breas t. We report the clinicopathologic features of 13 cases that were also examined by image analysis for DNA ploidy. The results were then anal yzed collectively with the less than 100 cases of salivary duct carcin oma reported in the English-language literature to define the characte ristics of this unusual neoplasm. The 12 men and one woman averaged 68 years of age (range, 49 to 90 years). All tumors arose in the parotid (10 cases) or submandibular glands (three cases). Nine tumors were an euploid, three diploid, and one was indeterminate because of insuffici ent tissue. Follow-up (median, 24 months) was available in 12 cases: t hree patients cried of disease, six were alive without disease, and th ree died of other causes. Combining our cases with those in the litera ture, a total of 104 cases, confirms that salivary duct carcinoma is a highly malignant neoplasm with distinctive clinical and pathologic fe atures. It arises almost exclusively in the major salivary glands (96% of cases), is three times more common in men, and usually occurs in p atients over 50 years of age (range, 22 to 91 years). One-third of pat ients experience local recurrences, 59% develop positive regional lymp h nodes, 46% have systemic metastases (lungs and bones), and 65% die o f their disease, usually within 4 years of diagnosis. Determination of tumor ploidy has no prognostic significance. The presence of distant metastasis was the only clinicopathologic feature that was statistical ly associated with prognosis (p = 0.02); all patients with systemic me tastasis died of disease.