Papillary-predominant adenocarcinoma of the lung
Papillary-predominant adenocarcinoma of the lung is a histological subtype of non-mucinous invasive adenocarcinoma of the lung.
In 2011, the International Association for the Study of Lung Cancer (IASLC), American Thoracic Society (ATS), and European Respiratory Society (ERS) introduced a new classification and terminology for adenocarcinoma of the lung, which is now divided into 'preinvasive', 'minimally invasive', and 'invasive'.
The term bronchoalveolar carcinoma (BAC) has been retired, and it is recommended that all invasive adenocarcinomas be classified in terms of the "predominant" comprising histology . Both mucinous and non-mucinous adenocarcinomas typically consist of a mixture of histologic patterns, but reporting of the predominant subtype (lepidic, acinar, papillary, micropapillary, or solid growth) is specifically recommended for non-mucinous lesions, with all mucinous tumors placed in a separate category.
It may account for 7-12% of all lung adenocarcinomas. There may be predilection in female non-smokers.
It this form papillary structures replace the underlying alveolar architecture. True papillary adenocarcinoma is usually diagnosed when the pathological features constitute >75% of the tumor on histopathology.
Variable appearances have been described ranging from a solitary pulmonary nodule, as a mass containing internal bubble lucencies with surrounding ground-glass opacity and satellite micronodules or as a triangular mass with satellite micronodules .
Treatment and prognosis
The presence of a micropapillary component in papillary carcinoma has been associated with early lymph node metastasis, intrapulmonary metastasis and a significantly lower 5-year survival rate.