Coexistence of carcinoid tumor and adenocarcinoma of the lung; morphological, immunohistochemical and genetic analyses, a case report

Abstract

Background Pulmonary carcinoid tumors rarely coexist with non-small cell lung carcinoma, and only nine cases have been reported previously. The pathogenesis and origin of these combined tumors remain unclear because of its rarity. Case presentation We examined two cases of adenocarcinoma coexisting with a typical or atypical carcinoid tumor: Case 1 was a 77-year-old woman and Case 2 was an 83-year-old woman. Both of these cases had no respiratory symptoms, and underwent pulmonary lobectomies due to incidentally detected lung nodules. Recurrence and metastases were not detected after the surgery. Histologically, carcinoid and adenocarcinoma components were present in both cases. The two components coexisted without mixing with each other. Next-generation sequencing was performed on the two components in these cases. In each case, no common genetic variants were detected. Conclusion We considered that our cases could histologically and genetically represent collision tumors that did not share common progenitor cells. Comprehensive analyses such as whole genome sequencing could provide important information for elucidating the pathogenesis of adenocarcinoma and carcinoid components.

Two Different Tumors and Lung Aspergilloma: An Uncommon Etiopathogenic Association

“…Pulmonary carcinoid tumors are considered rare neoplasms, with variable incidence rates ranging from 0.2 to 2 cases per 100,000 individuals in both the United States of America and Europe [ 1 ]. They represent 20–30% of all carcinoid tumors and 1–2% of all malignant lung tumors [ 1 , 2 , 3 ]. However, over the last four decades, the incidence of carcinoid tumors has increased by about 6% per year, regardless of demographic factors like age, gender, or race [ 4 ].…”

“…The association of lung carcinoid tumors with non-small-cell lung cancer (NSCLC) is extremely infrequent [ 2 ]. After analyzing the data from the literature, only 11 cases of the two types of malignancies were identified [ 2 ].…”

“…The association of lung carcinoid tumors with non-small-cell lung cancer (NSCLC) is extremely infrequent [ 2 ]. After analyzing the data from the literature, only 11 cases of the two types of malignancies were identified [ 2 ]. Out of the total number of patients, four had adenocarcinomas associated with typical carcinoid tumors (TCs), two had squamous carcinomas associated with TCs, four had atypical carcinoid tumors (ACs) associated with adenocarcinomas, and one had an AC associated with a squamous carcinoma [ 2 ].…”

“…After analyzing the data from the literature, only 11 cases of the two types of malignancies were identified [ 2 ]. Out of the total number of patients, four had adenocarcinomas associated with typical carcinoid tumors (TCs), two had squamous carcinomas associated with TCs, four had atypical carcinoid tumors (ACs) associated with adenocarcinomas, and one had an AC associated with a squamous carcinoma [ 2 ]. In each case, the tumors were found to be localized exclusively at the pulmonary level [ 2 ].…”

“…Out of the total number of patients, four had adenocarcinomas associated with typical carcinoid tumors (TCs), two had squamous carcinomas associated with TCs, four had atypical carcinoid tumors (ACs) associated with adenocarcinomas, and one had an AC associated with a squamous carcinoma [ 2 ]. In each case, the tumors were found to be localized exclusively at the pulmonary level [ 2 ]. The pathophysiology of this connection between cancerous conditions is not well understood.…”