Clinicopathological, immunohistochemical and mutational analyses of pulmonary enteric adenocarcinoma: Usefulness of SATB2 and β-catenin immunostaining for differentiation from metastatic colorectal carcinoma

• Published in: Human pathology 2017-06, Vol.64, p.179-185
• Main Authors: Matsushima, Jun, MD, Yazawa, Takuya, MD, Suzuki, Masaki, MD, Takahashi, Yoko, MD, Ota, Satoshi, MD, Nakajima, Takahiro, MD, Yoshino, Ichiro, MD, Yokose, Tomoyuki, MD, Inoue, Toru, MD, Kawahara, Kunimitsu, MD, Nakatani, Yukio, MD
• Format: Article
• Language: English
• Subjects: Adenocarcinoma - chemistry; Adenocarcinoma - diagnosis; Adenocarcinoma - genetics; Adenocarcinoma - pathology; Adenocarcinoma of Lung; Adult; Aged; beta Catenin - analysis; Biomarkers, Tumor - analysis; Biomarkers, Tumor - genetics; Biopsy; Colorectal cancer; Colorectal Neoplasms - chemistry; Colorectal Neoplasms - diagnosis; Colorectal Neoplasms - genetics; Colorectal Neoplasms - pathology; Deoxyribonucleic acid; Diagnosis, Differential; DNA; DNA Mutational Analysis; Exons; Female; Genetic Predisposition to Disease; Humans; Immunohistochemistry; KRAS; Lung Neoplasms - chemistry; Lung Neoplasms - diagnosis; Lung Neoplasms - genetics; Lung Neoplasms - secondary; Male; Matrix Attachment Region Binding Proteins - analysis; Metastasis; Metastatic colorectal carcinoma; Middle Aged; Morphology; Mutation; Pathology; Patients; Phenotype; Predictive Value of Tests; Proto-Oncogene Proteins p21(ras) - genetics; Pulmonary enteric adenocarcinoma; SATB2; Software; Statistical analysis; Transcription Factors - analysis; Tumor Burden; Tumors; β-Catenin
• ISSN: 0046-8177; 1532-8392
• DOI: 10.1016/j.humpath.2017.04.006

Pulmonary enteric adenocarcinoma (PEA) is a rare variant of pulmonary adenocarcinoma; it is sometimes difficult to discriminate between PEA and metastatic colorectal carcinoma (MCRC) because of their morphological and immunohistochemical resemblance. Here, we conducted clinicopathological, immunohistochemical, and mutational analyses of PEA with special focus on its differentiation from MCRC. We comparatively analyzed eight surgically resected PEA tumors (7 patients) and 20 cases of MCRC. Patients were aged 43–77 years (average age, 64.1 years); five of seven patients were men. Tumor sizes ranged from 1.5–11.5 cm (average size, 4.8 cm). The follow-up period was 1–65 months; four patients are alive without recurrence, two with recurrence, and one patient died of idiopathic pulmonary fibrosis. Six of the tumors were pure PEA; one PEA tumor had a small mucinous adenocarcinoma component; another had a squamous cell carcinoma component. Immunohistochemically, the positive rates of PEA for each antibody were as follows: CK7, 88% (7/8); CK20, 88% (7/8); TTF-1, 13% (1/8);β-catenin, 0% (0/8, strong nuclear expression); and special AT-rich sequence-binding protein 2 (SATB2), 13% (1/8). The positive rates of MCRC for these antibodies were 10%, 95%, 5%, 55%, and 100%, respectively. Genetic analysis of KRAS , EGFR, and BRAF showed the G12 V mutation in exon 2 of KRAS in one PEA. The present study's findings indicate that β-catenin and SATB2 are useful immunohistochemical markers for differentiating between PEA and MCRC.