A case of combined small cell lung carcinoma with unique morphology: Investigation of tumorigenesis

Abstract

Small cell lung carcinoma (SCLC) usually grows in a pure form with no other associated histological components. However, combined small cell lung carcinoma (cSCLC), which is accompanied by other histological components (cSCLCs) may sometimes occur. Herein, we analyzed the tumorigenesis of cSCLC containing a demarcated area of pure SCLC. A 76‐year‐old man had a 25‐mm mass in the perihilar portion of his right upper lung. Histologically, the cSCLC contained two relatively demarcated areas: one area composed of pure SCLC cells and another area of SCLC, squamous‐like component (SLC), and spindle cell carcinoma (SpCC) cells. Loss of heterozygosity (LOH) was observed at allele 3p in all tumor components and at 22q in the pure SCLC component. Histological and immunohistochemical analysis and LOH study suggested that all components were likely to be monoclonal in origin and revealed that the pure SCLC component was not the precursor of the cSCLC. In the tumorigenesis of this case, the pure SCLC and the cSCLC may have originated from a common pluripotent tumor cell and then diverged, although we cannot state this conclusively. Further studies with more cases are necessary to test this theory.

Case Report: Combined Small Cell Lung Carcinoma With Pulmonary Adenocarcinoma

“…According to 2004 WHO/International Association for the Study of Lung Cancer (IASLC) classification of lung and pleural tumors, CSCLC is defined as cancer tissues that mainly contain SCLC components with non-SCLC (NSCLC) histopathological types. The most common part of NSCLC is squamous cell carcinoma or large cell carcinoma (4,5). CSCLC contains adenocarcinoma is extremely rare (6).…”

Autopsy case of a patient with rapidly progressive combined small‐cell lung carcinoma with spindle‐shaped cell tumor

“…C-SCLC is defined as the concurrence of SCLC and any histological type of NSCLC, which is usually adenocarcinoma and squamous cell carcinoma, 6 or less commonly, spindle-shaped cell tumor. 2 Including our patient, there have been seven case reports of C-SCLC with spindleshaped cell tumor (Table 2), [7][8][9][10][11][12] and four cases of C-SCLC with three different components (Table 2).…”

Combined small cell lung carcinoma with pulmonary adenocarcinoma

“…According to the 2004 WHO/International Association for the Study of Lung Cancer (IASLC) classi cation of lung and pleural tumors, CSCLC is de ned as SCLC combined with one of the histological types of non-SCLC, usually squamous cell carcinoma or large cell carcinoma 4,5 . CSCLC contains adenocarcinoma is extremely rare and has been reported to account for less than 1-3% of CSCLC 6 .…”