Clinicopathologic characteristics and management of pulmo-nary enteric adenocarcinoma:an observational study

Yu Chen; Yajie Wang; Xiuhong Nie

Abstract：Objective To explore the clinicopathological characteristics of pulmonary enteric adenocarcinoma (PEAC) and its treatment and prognosis. Methods Patients with pathologically confirmed PEAC treated at Xuanwu Hospital, Capital Medical University, between 2019 and 2023 were retrospectively identified. Patients with colorectal adenocarcinoma were excluded. Clinical manifestations, imaging findings, pathological findings, treatment regimens, and prognostic data were reviewed. Results Eight patients (three male, five female) of median age 67.5 years (range 50-79) were included. The most common symptom was cough (62.5%), with some patients reporting shortness of breath and chest tightness. Chest CT revealed soft tissue masses in six cases, a ground-glass nodule in one case, and multiple nodules accompanied by pleural effusion in one case. Histological examination showed tall columnar tumor cells that formed glandular or sieve-like structures. Immunohistochemistry showed that all cases were CK7-positive, seven were CDX2-positive, five were CK20-positive, five were villin-positive, and three were positive for all four markers. Genetic testing showed epidermal growth factor receptor gene mutation positivity in one case and Kirsten rat sarcoma viral oncogene homolog gene mutation positivity in another. Three patients with stage I-II disease underwent surgery, three with stage IV disease received chemotherapy and immunotherapy, and one with stage II disease received targeted therapy. The follow-up data showed that the prognosis of PEAC was related to clinical stage and the treatment regimen, with the longest survival being 58 months. Conclusions PEAC is a rare type of lung adenocarcinoma with clinicopathological features similar to those of colorectal adenocarcinoma. Chest CT often shows a large soft tissue shadow, which must be diagnosed by a combination of pathology and immunohistochemistry. Early diagnosis, multimodal treatment, and immunotherapy may prolong survival.