Clinicopathologic features and genomic analysis of pulmonary blastomatoid carcinosarcoma

Adult Pulmonary Blastoma: A Case Report with Spectrum of Rare Manifestations

Pulmonary blastoma (PB) is an exceedingly rare and aggressive malignant lung neoplasm that has distinct biphasic morphology. In this report, we document rare manifestations and molecular alterations in PB. A 59-year-old non-smoker female, presented with cough and hemoptysis for 4 months. The high-resolution computed tomography chest scan showed a 3.5x2.7 cm mass in the basal segment of the left lung. Positron emission tomography and computed tomography revealed a fluorodeoxyglucose avid lobulated mass in the superior segment of the lower lobe of the left lung. On core biopsy, the diagnosis of pleomorphic carcinoma in a background of adenocarcinoma was made. A definite diagnosis of pulmonary blastoma was established on the left lung lobectomy specimen based on morphological and immunohistochemical findings. Post-surgical biopsy from the scalp swelling showed metastatic deposits. On Next Generation Sequencing (NGS), in addition to conventional CTNNB1 gene mutation, new pathogenic MYCN and ATM gene mutations were detected. Post-chemotherapy, the patient was doing well after 10 months of close follow-up. PB exhibited rare associations in the form of non-smoker status, scalp metastasis, and MYCN and ATM gene mutations on NGS in addition to conventional CTNNB1 gene mutation. Large cohort studies are required to discover the incidence, significance and therapeutic implications of these co-existing pathogenic molecular alterations in PB.

DICER1-associated sarcoma of the aortic arch - a case report and literature review

Primary sarcoma of the aorta is extremely rare. We herein report a case of DICER1-associated sarcoma originating from the aortic arch. A 45-year-old male was admitted to the hospital with a cold left hand and weakened radial artery pulse in the left side. Computed tomography of the chest showed multiple penetrating ulcers with tumor-like ectasia at the aortic arch, diagnosed as a pseudoaneurysm. Histopathological analysis of the mass revealed a biphasic neoplasm composed of epithelial and mesenchymal components and a transition zone between the epithelial and mesenchymal cells, which supports the diagnosis of a biphasic sarcoma rather than carcinosarcoma. The differentiated cells of soft tissue showed strong and diffuse positivity for TLE-1, Bcl-2, and CD99; the nested epithelial cells were focally positive for CK-pan, but negative for EMA, membranous localization of β-catenin. This case showed a unique pattern of SS18-break-apart probe, with loss of the green signal (approximately 33%) by fluorescence in situ hybridization (FISH). Fusion gene profiling using whole transcriptome RNA sequencing (RNA-seq) indicated that this case was negative for common fusion genes including SS18. Next-generation sequencing (NGS) revealed somatic mutations in DICER1 . Taken together, this case was diagnosed as a DICER-associated biphasic sarcoma of the aortic arch. The patient died four months after aorta replacement therapy without radiotherapy and chemotherapy.

Correlation between LRP1B Mutations and Tumor Mutation Burden in Gastric Cancer

BACKGROUND

It has been shown that low-density lipoprotein receptor-related protein 1B (LRP1B) mutations correlate with tumor mutation burden (TMB) and prognosis in patients with melanoma and non-small-cell lung cancer, while the relationship between LRP1B mutations and TMB in gastric cancer needs further study. This study is aimed at exploring the relationship between LRP1B mutations and TMB in gastric cancer.

METHODS

Mutation frequency profiles of the genes in patients with gastric cancer in TCGA-STAD dataset were analyzed by bioinformatics analysis. The relationship among LRP1B mutations, TMB, and patient clinical features in gastric cancer was investigated by the chi-square test. The TMB prediction capacity based on LRP1B mutation status was evaluated by ROC curves.

RESULTS

LRP1B is one of the top 10 genes with high gene mutation frequency in gastric cancer. The mutation status of LRP1B in gastric cancer patients was significantly correlated with age and TP53 and MUC16 mutation status. The result of ROC curve analysis revealed that the mutation status of LRP1B could be considered as an indicator of the degree of TMB in patients with gastric cancer.

CONCLUSION

This study presented the relationship between TMB and LRP1B mutations in gastric cancer, providing a novel perspective for gastric cancer prognosis and therapy.