Transformation of lung adenocarcinoma to small cell lung carcinoma in the setting of tyrosine kinase inhibitor therapy: Cytological approach of a clinically challenging phenomenon

Abstract

Lung adenocarcinoma transformation into small cell lung carcinoma is a wellestablished phenomenon. Several reports and studies have been published, describing the clinical and pathological clues to detect this transformation. This article will discuss the cytological aspect of this entity, highlighting pertinent features, to bring more attention to the existence of this transformation into the cytopathology practice. K E Y W O R D S cytology features, NSCLC, SCLC, transformation

Histological transformation of non-small cell lung cancer: Clinical analysis of nine cases

“…In our study, cases 1 and 4 shared the EGFR 19del before and after transformation onset. In addition, SCLC has a lower rate of EGFR mutation than NSCLC[ 13 ]. Furthermore, alveolar type II cells may be the common progenitor of ADC and SCLC with EGFR mutations[ 9 ].…”