Background OSBPL3 is overexpressed in a variety of malignancies and is closely associated with tumor growth and metastasis. However, its expression and function in colorectal cancer (CRC) are unclear. We aimed to investigate its prognostic and therapeutic value in this disease by detecting its expression in CRC and its correlation with the clinicopathological characteristics and prognosis of patients. Methods A total of 92 CRC samples were included in this study. According to the 2020 WHO diagnostic criteria, the criteria of the American Joint Committee on Cancer (AJCC) 8th edition staging system were used. OSBPL3 and Ki-67 expression in these samples was detected by immunohistochemistry. OSBPL3 mRNA expression was detected by qRT-PCR. KRAS/NRAS mutations were detected by an amplification refractory mutation system (ARMS). Data analysis was performed using the statistical analysis software Prism 8. Results OSBPL3 was found to be significantly overexpressed in CRC tumor tissues and was associated with worse progression-free survival and overall survival in patients. Additionally, OSBPL3 expression was negatively correlated with the degree of tumor differentiation. KRAS mutations were detected in approximately 32.6% of patients and were significantly associated with high OSBPL3 expression. In addition, OSBPL3 and Ki-67 expression was significantly correlated. Conclusions OSBPL3 is highly expressed in CRC samples and predicts a worse prognosis. OSBPL3 may become a new potential therapeutic target for CRC.

Aims: Nodal T follicular helper (TFH) cell lymphoma (nTFHL) is a rare type of clinically aggressive T cell lymphoma. With this lymphoma type, Epstein-Barr virus (EBV) infection is frequently detected in nonneoplastic B lymphocytes, but not yet identified in neoplastic T cells. We report two cases of nTFHL showing a classic morphology and immunoprofile, with EBV-encoded small RNAs (EBER) in-situ hybridisation positivity in neoplastic TFH cells. Methods and results: Clonal T cell receptor (TR) gene rearrangement was detected in both cases. Whole exome sequencing identified TET2, RHOA p. G17V, as well as gene mutations unique to each case. Microdissection analysis showed EBER positivity in tumour cells and in background non-neoplastic T lymphocytes. Conclusion: These two immunocompetent cases of nTFHL with EBV-positive tumour cells exhibit the featured gene mutation profile and poor prognosis of this disease. This novel finding of EBV positivity in our cases expands the currently recognised spectrum of EBV-positive nodal T cell lymphomas to include rare cases of nTFHL.

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