Sa. Silver et Fb. Askin, TRUE PAPILLARY CARCINOMA OF THE LUNG - A DISTINCT CLINICOPATHOLOGICALENTITY, The American journal of surgical pathology, 21(1), 1997, pp. 43-51
There continues to be confusion as to whether papillary adenocarcinoma
(PA) of the lung is a specific histologic entity or simply a variant
of bronchioloalveolar carcinoma (BAG). We reviewed our files from 1981
through 1993 for all cases (n = 155) of resected primary lung adenoca
rcinoma specifically diagnosed as having papillary or bronchioloalveol
ar features. In addition, a random 10% (n = 67) of all remaining lung
adenocarcinomas were reviewed. True PA was diagnosed when greater than
or equal to 75% of the neoplasm contained papillary structures suppor
ted by fibrovascular cores with complicated secondary and tertiary bra
nches. Marked nuclear atypia was present in 100%, and psammoma bodies
were seen in 42% of cases. In contrast to BAG, true PA filled and dist
orted or replaced air spaces in the lung. Thirty-one cases of true PA
were found, including 19 men and 12 women (mean age, 64.5 years). The
lesions were solitary (n = 27) or multifocal (n = 4) with a mean diame
ter of 4.1 cm. Forty-five percent of patients had bronchopulmonary lym
ph node involvement at diagnosis; another 10% had extensive intrapulmo
nary lymphatic permeation by tumor. Disease-free survival for stage I
and II PA was 40% (n = 15) and 25% (n = 8), respectively, at a mean of
3.4 and 3.5 years. Papillary adenocarcinoma of the lung is a distinct
clinicopathologic entity with considerably worse morbidity and mortal
ity than BAC.