Cytochemical studies for determining the histogenesis of anaplastic and poorly differentiated lung tumors

: Proper histogenetic classification of pulmonary tumours is most important in choosing the best possible treatment. Since this is very difficult especially in case of anaplastic or poorly differentiated tumours, additional pointers on histogenesis, supplied by complementary histochemical examinations, are very helpful. 105 bronchial carcinomas were examined cytochemically by means of air-dried smear preparations (imprint, brush an puncture smears). Cytochemical examinations were performed in respect of alkaline phosphatase, acid phosphatase, PAS reaction and unspecific esterase. It was found that the dedifferentiated squamous cell carcinomas were alkaline phosphatase-negative and weakly positive to acid phosphatase and unspecific esterase, whereas dedifferentiated adenocarcinomas were strongly positive to acid phosphatase and unspecific esterase. The PAS reaction was always slightly to moderately positive. Small-cell bronchial carcinomas were negative in all cytochemical examinations.