[Study of genetic variants in 169 non-small cell lung cancer patients]. / Estudio de variantes genéticas en 169 pacientes de cáncer de pulmón no microcítico.

INTRODUCTION: Lung cancer is the leading cause of cancer death in our country. Non-small cell lung cancer (NSCLC) represents the paradigm of personalized medicine. The main objective of this study is analysing the distribution of the most frequently described clinically significant variants in NSCLC, in our environment. MATERIAL AND METHODS: We studied the immunohistochemical expression of TTF1, p40 and PD-L1 and the genetic variants frequency using Next-Generation Sequencing (NGS) with a panel of 52 genes, in 174 NSCLC paraffin-embedded samples in 169 patients (111 men and 52 women) from the province of Cádiz. RESULTS: The immunohistochemical expression of TTF1, p40 and PD-L1 was positive in 87%, 0% and 46% in adenocarcinoma, and 0%, 100% and 41% in squamous cell carcinoma. In NGS, the most common single nucleotide variants (SNVs) were KRAS (36%), EGFR (14%), BRAF (10%), PIK3CA (8%), and MET (3%). The most frequent copy number variants (CNVs) were amplifications in NF1 (30%), EGFR (18%), CCND1 (9%), MYC (9%) and KRAS (7%). In women, SNV in EGFR are more frequent than in men (P<.0001). Adenocarcinoma is the most frequent histological type with SNV in KRAS (P=.007361) or in EGFR (P<.0001). Gene fusions were detected in 16 patients (9.47%), in 9 cases in the MET gene. CONCLUSIONS: We detected associations, not described so far, between immunohistochemical expression and specific gene variants, which could have an impact on the treatment of NSCLC patients.

Ectopic ACTH syndrome in a patient with Crohn's disease.

We present the case of a 62-year-old man with Crohn's disease who consulted for abdominal pain and lower limbs edema. The patient developed Cushing's syndrome due to ectopic secretion of ACTH. Diagnostic imaging tests showed multiple metastatic liver lesions and asymmetric thickening of the ileum, that was suspected as the primary tumor. This tumor produced destabilizing gastrointestinal bleeding and an urgent surgical resection was performed. The histopathological study of the resection specimen confirmed a grade 3 neuroendocrine tumor.

18F-FDG PET/CT in lung B lymphoid hyperplasia-type Castleman disease.

We present a 62-year-old woman who, after a catarrhal episode, underwent a chest xray and a chest CT, identifying a pleural-based mass in the left lower lobe. This lesion presented a mixed pattern with solid and peripheral ground-glass attenuation, and an air-bronchogram sign. Despite de suspicion of bronchopneumonia, a lung neoplasm like a predominantly lepidic adenocarcinoma could not be ruled. A 18 F-FDG PET/CT showed a focal radiotracer uptake with SUVmax of 5.34 in the pulmonary lesion, supporting the neoplastic etiology. Consequently, a lower lobectomy was performed and histological examination concluded that the final diagnosis was a B lymphoid hyperplasia-type Castleman disease. Castleman's disease is an uncommon disorder that can be easily misdiagnosed as lymphoma, neoplasm or infection. Unicentric Castleman's disease (UCD) usually presents a hyaline-vascular histological subtype and is usually asymptomatic. Extranodal involvement is very rare. Only a few cases of solid organ involvement such us spleen or parotid gland have been described. UCD originating in the lung is extremely rare and should be considered in the differential diagnosis of a primary pulmonary malignant tumor.