PMC8403576_01
Chest computed tomography at the first time of diagnosis. The image shows a 21 x 23 mm mass in the right upper lobe (A) and usual interstitial pneumonia pattern in the lung base (B, arrow).
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Chest computed tomography (CT) revealed a 21 x 23 mm nodule in the right upper lobe (Fig. 1A) with CPFE (Fig. 1B) and consolidation in the right lower lobe.
Positron emission tomography-computed tomography image. Fluorodeoxyglucose accumulation was observed in the tumor in the right upper lobe.
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Positron emission tomography (PET)-CT further revealed the accumulation of fluorodeoxyglucose in the nodule (maximum standardized uptake value: 18.8) (Fig. 2), but there were no findings suggestive of metastasis.
Histopathological findings. The nodule stained for CK7 (A, x 40), CK20(B, x 40), TTF-1 (C, x 40), HE(D, x 20). The tumor consisted of necrotic and granulation tissue, with infiltration of inflammatory cells. Invasive growth of poorly differentiated pleomorphic carcinoma with spindle cells was observed.
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PD-L1 expression had a tumor proportion score of 40% (Fig. 3). Polymerase Chain Reaction invader assay showed EGFR mutation was negative.
Abdominal computed tomography at the time of recurrence. A is an axial section, B is a coronal section and C is a positron emission tomography-computed tomography image. A 121 x 71 mm large irregular mass extending caudal to the posterior wall of the lower stomach was seen (arrow).
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In June, two years after the surgery, abdominal CT showed a 121 x 71 mm large irregular mass extending caudally to the lower stomach's posterior wall (Fig. 4).
Abdominal computed tomography (CT) (A) and positron emission tomography-CT (B) after two cycles of S-1 treatment.
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S-1 (100 mg/day for four consecutive weeks, followed by a two-week rest period, in a six-week cycle) as second-line therapy in August. Surprisingly, the tumor dramatically shrunk at four months after two cycles of S-1 therapy (Fig. 5).