Sequential occurrence of T790M mutation and small cell lung cancer transformation in EGFR-positive lung adenocarcinoma: A case report

Figure 1 Transformation of chest computed tomography following various regimens. A: The baseline findings on chest computed tomography; B: Partial response (PR) after oral gefitinib 250 mg daily for 4 mo; C: Enlarged lesion in the right upper lobe and increased metastatic nodules after oral gefitinib 250 mg daily for 10.5 mo; D: Enlarged lesion in the right upper lobe with near disappearance of metastasis after oral Osimertinib 80 mg daily for 1 mo; E: Progressive disease (PD) after oral osimertinib 80 mg daily for 3 mo; F: PR after 4 cycles of etoposide + carboplatin; G: PD after 6 cycles of etoposide + carboplatin; H: Stable disease following 4 cycles of docetaxel + carboplatin + anlotinib.

Figure 2 Changes in pathological morphology and immunohistochemistry. A: November 5, 2016, indicated adenocarcinoma, immunohistochemistry (IHC): CK-7+++, TTF-1+++; B: January 5, 2018, resistance to osimertinib, indicated small cell lung cancer, IHC: Syn+, TTF-1+; C: September 28, 2018, resistance to docetaxel + carboplatin + Anlotinib, suggested adenocarcinoma and small cell lung cancer, IHC: Syn+, NapsinA+. Magnification ×100.

Figure 3 Fluctuations in serum carcinoembryonic antigen and neuron-specific enolase. NSE: neuron-specific enolase; CEA: carcinoembryonic antigen.

Figure 4 Timeline of our case’s treatment with multiline therapy.