Lung adenocarcinoma coexisting with diffuse idiopathic pulmonary neuroendocrine cell hyperplasia manifesting as multiple pulmonary nodules: A case report

• Published in: Thoracic cancer Vol. 13; no. 21; pp. 3076 - 3079
• Main Authors: Inomata, Sho, Matsumura, Yuki, Kobayashi, Yasuyuki, Yamaguchi, Hikaru, Watanabe, Masayuki, Ozaki, Yuki, Muto, Satoshi, Okabe, Naoyuki, Shio, Yutaka, Suzuki, Hiroyuki
• Format: Journal Article
• Language: English
• Published: Melbourne John Wiley & Sons Australia, Ltd 01.11.2022; John Wiley & Sons, Inc; Wiley
• Subjects: Adenocarcinoma of Lung - pathology; Aged; Cancer; Case Report; Case Reports; diffuse idiopathic pulmonary neuroendocrine cell hyperplasia; epidermal growth factor receptor; Female; Humans; Hyperplasia; lung adenocarcinoma; Lung cancer; Lung Neoplasms - pathology; Lungs; Lymphatic system; Metastasis; Multiple Pulmonary Nodules - pathology; Neuroendocrine Cells - metabolism; Neuroendocrine Cells - pathology; Patients; Targeted cancer therapy; Tumors; tyrosine kinase inhibitor; diffuse idiopathic pulmonary neuroendocrine cell hyperplasia; tyrosine kinase inhibitor; epidermal growth factor receptor; lung adenocarcinoma
• ISSN: 1759-7706; 1759-7714
• DOI: 10.1111/1759-7714.14662

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH), a rare condition, is characterized by pathological proliferation of neuroendocrine cells. Some of them are localized to the airway mucosa, and others locally infiltrate to form tumorlets and nodules. Here, we present a patient with lung adenocarcinoma accompanied by DIPNECH, making the latter difficult to distinguish from multiple pulmonary metastases. The patient, a 72‐year‐old Japanese woman, was diagnosed as having stage IVA lung adenocarcinoma because she had multiple nodules in both lungs. Mutation of epidermal growth factor receptor gene having been found in the primary tumor, treatment with osimertinib was started. This resulted in shrinkage of the primary tumor, but not the multiple pulmonary nodules. To determine whether these lung nodules were indeed lung metastases, we performed right upper lobectomy with lymphadenectomy and wedge resection of the right lower lobe. On pathological examination, the primary tumor was diagnosed as invasive adenocarcinoma, whereas the multiple pulmonary nodules were diagnosed as DIPNECH manifesting as tumorlets. Therefore, the final diagnosis was stage IA1 lung adenocarcinoma accompanied by DINPECH. The patient had no recurrences 1 year after the operation without any additional treatment. This is a rare case of lung adenocarcinoma accompanied by DIPNECH presenting as multiple pulmonary nodules. DIPNECH should be included in the differential diagnosis of multiple pulmonary nodules. Patient's clinical course. After diagnosed of clinical stage IVA lung adenocarcinoma, the patient was treated by osimertinib. The primary tumor shrank after administration of osimertinib, whereas the multiple pulmonary nodules did not change. Therefore, we performed a surgical resection of the primary tumor and wedge resection of some of the small nodules. The patient was followed up without any additional treatment after the multiple nodules were diagnosed of DIPNECH. The patient has had no recurrences 1 year after the operation with no additional treatment.