[Growth of squamous cells lung cancer between alveolar basement membrane and alveolar epithelium]

We examined patterns of growth of cancer cells in specimens of alveoli taken from 41 patients with squamous cell carcinoma (36 men and 5 women, mean age 65 years). For comparison, 8 samples from patients with small cell carcinoma (6 men and 2 women, mean age 64) and 71 samples from patients with adenocarcinoma (48 men and 23 women, mean age 62) were also studied. The samples were fixed in formalin, embedded in paraffin, and then subjected to immunostaining. Glandular structures composed of non-atypical cuboidal cells with negative p53 staining and scanty positive PCNA staining were found in 90% of the samples of squamous cell carcinoma. In small cell carcinoma, 25% of the samples had small numbers of no-atypical glandular structures. In adenocarcinoma, no non-atypical glandular structures were seen. Glandular structures were observed in the periphery of the cancerous tissue. Some of these non-atypical cells were attached to the alveolar basement membranes. We conclude that squamous cell carcinoma grows between the basement membrane and the alveolar epithelium, and leaves noncancerous epithelium with glandular structure.