Primary clear cell adenocarcinoma of the lung

Abstract

Primary clear cell adenocarcinoma of the lung is extremely rare. A 63-year-old Japanese man consulted to our hospital because of cough and sputum. Imaging modalities including XP, CT and MRI revealed a tumor of the right middle lobe. They did not identify other tumors in the body. Because clinical cytology and biopsy showed malignant cells, segmentectomy of the lobe was performed. Grossly, the tumor was whitish tan tumor measuring 5 × 6 × 5 cm. Histologically, the tumor was composed entirely of clear cells arranged in papillary and tubular patterns. The tumor cells had hyperchromatic nuclei, and mitotic figure and nuclear stratification were scattered. Histochemically, glycogen and mucins were absent in tumor cell cytoplasm. Immunohistochemically, the tumor cells were positive for pancytokeratin (AE1/3, CAM5.2), cytokeratin (CK) 7, CK 8, CK18, CK19, EMA, CEA, CA19-9, CA125, p53, Ki-67 (labeling = 80%), TTF-1 and surfactant apoprotein A. In contrast, the tumor cells were negative for CK5/6, CK 34βE12, CK 14, CK 20, vimentin, desmin, S100 protein, α-smooth muscle actin, AFP, HMB45, CD10, CD34, HER2/neu, CD56, p63, and synaptophysin. The tumor recurred 6 months after the operation, and right middle lobectomy was performed. Postoperative imaging modalities showed no tumors. The patient is alive free from tumor 9 years after the first manifestation.

Analysis of mutational and clinicopathologic characteristics of lung adenocarcinoma with clear cell component

“…This finding is in agreement with ALA Katzenstein et al, who found 4 lung adenocarcinomas with clear cell component and two of them died within one year [ 7 ]. Although a previous study regarded lung adenocarcinoma with clear cell component as a tumor with a relatively good outcome, the study only had one patient and would produce a bias [ 9 ].…”

“…Despite clear cell feature is useful to compare diverse lung tumors, the feature can occur in a variety of patterns of lung tumor [ 14 ]. It is a challenging work to distinguish lung adenocarcinoma with clear cell component from multiple lung tumors with clear cell component, such as PEComa, benign (with clear cell tumor as a variant), squamous cell carcinoma with clear cell feature, primary clear cell carcinoma and metastases from renal clear cell carcinoma [ 9 , 13 , 22 ]. Differential diagnosis is necessary for these tumors mentioned above and histological and immunochemical tests play important roles.…”

“…Differential diagnosis is necessary for these tumors mentioned above and histological and immunochemical tests play important roles. Tumor cells of lung adenocarcinoma with clear cell component may demonstrate finely vacuolated cytoplasm, reveal cytological and histological atypia recognized as lung adenocarcinoma [ 9 , 22 ]. PEComa exhibits strong cytoplasmic positivity for HMB-45 and is regarded as a benign tumor [ 23 ].…”

“…Despite that clear cell feature may occur in multiple histologic subtypes of lung adenocarcinoma, to our knowledge, lung adenocarcinoma with clear cell component is extremely rare and the cases reported in literature remain scarce [ 9 - 12 ]. Furthermore, the biological behaviors, clinicopathologic characteristics, mutational status and prognosis of lung adenocarcinoma with clear cell component are still undetermined.…”

Choroid metastases revealing primary clear cell adenocarcinoma of the lung effectively treated with cisplatin and pemetrexed: a case report

“…Adenocarcinoma with cells that are filled with clear cytoplasm and that are the major component of a lung tumor is defined as primary clear cell adenocarcinoma of the lung according to World Health Organization classification guidelines [ 6 ]. Because such pulmonary adenocarcinomas are very small in number, and the cases reported in the literature have shown varied biological natures and clinical presentations [ 7 ], the appropriate diagnostic procedures may help to establish an accurate diagnosis . Firstly, it is so histologically heterogeneous for pulmonary adenocarcinomas that we used video-assisted thoracoscopy to acquire enough tumor tissue, even though a fine-needle aspiration biopsy may enable early diagnosis and hence the initiation of immediate appropriate palliative therapy.…”