case_images: PMC6724481_01
case_images: (A, B) Thoracic CT-scan showing, blue arrow: a large lesion in RUL, diaphragmatic elevation, decreased bronchial lumen, mediastinal involvement, and mild right pleural effusion. (C, D) Thoracic CT-scan showing a decrease of the RUL lesion. Yellow arrow: a 2-cm opacity of irregular nodular aspect persists and horizontal fissure with small nodules, without evident mediastinal involvement. CT indicates computed tomography; RUL, right upper lobe.
case_images: 10.1177_1179548419872993-fig1.jpg
case_images: PMC6724481_01_10.1177_1179548419872993-fig1.jpg
case_images: fig1-1179548419872993
case_images: In the thoracic computed tomography (CT) scan, a mass of 10.5 x 8.8 cm was observed that affected almost all of the RUL, with multiple adenomegalies in the mediastinum, subcarinal, and in the right pulmonary hilum (Figure 1A and B). The thoracic CT-scan taken 6 months after the start of the medication showed a decrease in the size of the tumor, reporting a poorly defined 2 cm lesion of irregular contours in the RUL and horizontal fissure of nodular aspect with normal mediastinum (Figure 1C and D).
case_images: Sequential images of the histological evolution. (A, B) Primary tumor compatible with adenosquamous carcinoma. (A) Positivity for p40. (B) Positivity for TTF-1. (C) Adenocarcinoma in the cell block of the pericardial fluid cytology. H & E staining, blue arrow: cell block where it is appreciated pulmonary adenocarcinoma in pericardial effusion. Immunohistochemistry, yellow arrow: nuclear positivity for TTF-1. (D) Transformation to small cell carcinoma. H & E staining, blue arrow: component of squamous cell carcinoma. Yellow arrow: presence of small cell carcinoma transformed from the adenocarcinoma component. (E) Immunohistochemistry, blue arrow: positive p40 in squamous cell carcinoma. Yellow arrow: p40 negative in the small cell carcinoma component. (F) Immunohistochemistry, blue arrow: positivity for CD56 in the fragments of the transbronchial biopsy with representation of small cell carcinoma.
case_images: 10.1177_1179548419872993-fig2.jpg
case_images: PMC6724481_01_10.1177_1179548419872993-fig2.jpg
case_images: fig2-1179548419872993
case_images: TTF-1, Napsin A, and p40, compatible for diagnosis of primary adenosquamous carcinoma of the lung (Figure 2A and B). The genetic profile reported positive mutations for EGFR in exon 20 (S768I) and exon 21 (L858R), without rearrangements for the ALK gene. He entered the intensive care unit where the presence of pericardial effusion was documented, which was drained obtaining a cytology with the presence of malignant cells compatible with metastatic adenocarcinoma (Figure 2C). These findings lead to a diagnosis of adenosquamous carcinoma with transformation of the adenocarcinoma component to small cell carcinoma and persistence of the squamous component (Figure 2D-F). The genetic profile of this transformation reported EGFR with persistence of mutations in exon 20 (S768I) and exon 21 (L858R).
case_images: (A) Thoracic CT-scan with progression of the lesion of irregular aspect 5 x 3 x 3 cm in RUL with mediastinal involvement and satellite nodules. (B, C) Blue arrow: Thoracic CT-scan: large mass in RUL with involvement of structures of the pulmonary hilum, horizontal fissure, parietal and mediastinal pleura, pericardial sac with satellite nodules. (D) Yellow arrow: Brain MRI where there are multiple nodules of metastatic aspect. CT indicates computed tomography; RUL, right upper lobe.
case_images: 10.1177_1179548419872993-fig3.jpg
case_images: PMC6724481_01_10.1177_1179548419872993-fig3.jpg
case_images: fig3-1179548419872993
case_images: The chest X-ray showed a lesion of 5 x 3 cm in the RUL with compression of the bronchial lumen and mediastinal involvement Figure 3. A thoracic CT-scan was performed which revealed a greater progression of the lesion in the RUL with vascular and right bronchus involvement as well as pleural effusion (Figure 3B and C). The brain magnetic resonance imaging (MRI) showed multiple supra and infratentorial metastatic lesions with an ependymal nodule inside the right lateral ventricle (Figure 3D).