Polymorphous low-grade adenocarcinoma - A study of 40 cases with long-termfollow up and an evaluation of the importance of papillary areas

Forty cases of polymorphous low-grade adenocarcinoma with a minimum of 10 y ears of follow up were reviewed. The patients included 13 men and 27 women age 22 to 71 years (median age, 54 years); 30 were white and 10 were black. The tumors were all intraoral, and the palate was the most common site (n = 24). Histologically, the neoplasms were characterized by nonencapsulated, infiltrative borders; bland, regular nuclei; and highly variable growth pa tterns, including tubular, solid, papillary, microcystic, cribriform (with true lumens), pseudoadenoid cystic (without true lumens), fascicular, singl e file, and strand-like. Papillary areas of more than focal extent were pre sent in 17 cases, but these cases were otherwise similar to the remainder a nd were considered to form part of the spectrum of polymorphous low-grade a denocarcinoma. Thirteen patients had local recurrence, which was not contro lled by subsequent treatment in six; six patients had cervical lymph node m etastasis; three patients had distant metastasis; and five patients died of or with tumor after prolonged periods. There was a statistically significa nt relationship between more than focal papillary growth and cervical lymph node metastasis, and between positive or unknown surgical margins and loca l recurrence (although not uncontrolled local recurrence); however, these w ere the only independent statistically significant correlations found betwe en any clinical or pathologic parameter and any aspect of tumor behavior or patient survival.