Primary spleen extranodal NK/T cell lymphoma, nasal type, with bone marrow involvement and CD30 positive expression: a case report and literature review

Aims: Primay spleen NK/T cell lymphoma is very rare. We report a case of 39-years-old male of primary splenic NK/T cell lymphoma with bone marrow involvement and CD30 positive expression. Case description: The patient had high fever for 2 months, and CT scan revealed a diffuse splenomegaly without hepatomegaly. The diagnosis was established by splenectomy specimen and bone marrow biopsy. Normal spleen structure was destroyed by the diffusely infiltrated neoplastic cells, and one of the splenic hilar lymph nodes was involved. The lymphomatous cells were mainly medium-sized, mixed with small and large cells with pleomorphic nuclei and conspicuous nucleoli. Angiocentric growth pattern was present, with mitotic figures and apoptotic bodies easily being found. These neoplastic cells demonstrated a typical immunophenotype of CD2, CD3 epsilon, CD7, CD4, CD56, TIA-1, Granzyme B, CD30 positive, and CD5, CD8, CD20, CD79a negative. The Epstein-Barr virus encoded RNAs (EBERs) genomes were also found in tumor cells by in situ hybridization, while no clonal rearrangement of the T cell receptor-gamma genes (TCRG) was found. Biopsy of bone marrow revealed scattered atypical cells presented with a predominantly intrasinusoidal distribution. A diagnosis as primary spleen NK/T cell lymphoma, nasal type (ENKTL) with CD30 expression and bone marrow involvement was finally made. The patient received chemotherapy and was still alive 6 months after splenectomy. Clinical significance: Primary spleen ENKTL is very rare, it should be made with the combination of clinical feature, PET-CT image, and pathological characteristics, and should be distinguished from other lymphomas or leukemia involved in spleen.