The pathobiologic features of carcinomas of type II pneumocytes. An immunocytologic study

Abstract

Adenocarcinomas of the lung without squamous differentiation or obvious mucus production from 51 patients were studied. Twenty-eight tumors (55%), when stained with rabbit anti-human surfactant apoprotein antiserum by the peroxidase-antiperoxidase method, demonstrated characteristic nuclear inclusions. Most of these tumors could be identified histochemically by the presence of eosinophilic, periodic acid-Schiff (PAS)-positive nuclear inclusions. In patients with apoprotein-immunoreactive tumors there were nine deaths due to tumor (32%) within 5 years of diagnosis. Eight of the nine deaths occurred in patients whose tumors exceeded 3 cm in diameter; an equal number of patients were smokers. The average age of patients with apoprotein-positive tumors was 67.3 years, a figure greater than that for patients with apoprotein-negative tumors (61.4 years). Five of the 23 patients with apoprotein-negative tumors died of their neoplasms; in two of the subjects the tumors exceeded 3 cm in diameter. In that no significant difference in survival was observed in patients with apoprotein-positive and apoprotein-negative tumors, it was concluded that subclassification of adenocarcinomas of the lung as apoprotein-positive, i.e., type II pneumocytic, or as apoprotein-negative, is of no clinical or prognostic significance. Nonetheless, peripheral tumors measuring less than 3 cm in size and showing neither squamous differentiation nor obvious mucus production should be recognized as a prognostically favorable group in comparison with other types of lung carcinomas.

Value of thyroid transcription factor-1 and surfactant apoprotein A in the differential diagnosis of pulmonary carcinomas: a study of 109 cases

“…Previous studies indicated that pulmonary adenocarcinomas including bronchioloalveolar carcinomas contain SP-A mRNA [5] as well as immunoreactive SP-A protein detectable with monoclonal antibody PE-10 [23,25,26,35]. Furthermore, TTF-1 has been demonstrated in pulmonary adenocarcinomas [3,7,9,14,16], in pulmonary small cell carcinomas (SCLC) [9,11,28], and in thyroid carcinomas [14].…”

Prognostic significance of frequent acidophilic nuclear inclusions in adenocarcinoma of the lung with immunohistochemical and ultrastructural studies

“…8 They also demonstrated surfactant apoprotein positive ANIs in 28 of 51 adenocarcinomas (55%) in an immunocytologic study. 9 These findings suggest that more detailed examinations, especially electron microscopic and immunocytologic examinations, provide higher incidences of ANIs because they show minute, obscure, and rare inclusions more clearly. Standardization of the counting method is necessary to assess the incidence and prognostic significance of ANIs.…”

“…The majority of ANIs are immunohistochemically positive for surfactant apoprotein and had been regarded as differentiation to type 2 alveolar cells. [7][8][9] However, recent studies have shown that surfactant apoprotein is produced by not only type 2 alveolar cells but also by nonciliated bronchiolar epithelial cells (Clara cells). 19,20 Hence, surfactant apoproteinproducing carcinomas should be considered to have differentiation to type 2 alveolar cells or Clara cells.…”

“…6 -9 Some studies described ANI as a morphologic feature of carcinoma with differentiation to type 2 alveolar cells. [7][8][9] Tumor differentiation grade is a prognostic factor of many carcinomas, including pulmonary adenocarcinoma, 10 and if ANI is found to indicate some functional differentiation of tumor cells, the frequency of ANIs, as well as tumor differentiation grade, may have prognostic significance. Some studies have reported that the incidence of ANIs was higher in well differentiated adenocarcinoma 4,6 and one study suggested that papillary adenocarcinoma with ANIs may have a more favorable prognosis based on anecdotal observations of only a small number of cases; 11 however, statistically significant prognostic findings were not shown.…”

Lung surfactant protein-A and carcinoembryonic antigen in pleural effusions due to lung adenocarcinoma and malignant mesothelioma

“…SP-A appears to be synthesized and secreted from type II pneumocytes and nonciliated bronchiolar epithelial cells in the lung under normal condition [22]. SP-A has been immunohistochemically found in approximately half of primary lung adenocarcinomas, but not in other histological types of lung carcinomas or in metastatic lung tumours [23,24]. SP-A messenger ribonucleic acid (mRNA) was detected in 5 of 6 lung adenocarcinomas by in situ hybridization, but was not detected in a largecell lung carcinoma or six lung squamous cell carcinomas [22].…”