[Clinicopathologic characteristics and prognosis of neoplastic cell-rich mixed cellularity classic Hodgkin lymphoma]

Objective: To investigate the clinicopathologic characteristics of neoplastic cell-rich mixed cellularity classical Hodgkin lymphoma(MCCHL-R) and to compare the prognosis with typical mixed cellularity classic Hodgkin lymphoma(MCCHL). Methods: Fifty-four patients with MCCHL-R(the tumor cells >10%) and 65 patients with typical MCCHL identified from 1 721 Hodgkin lymphomas were reviewed to compare the clinicopathological characteristics including morphologic and immunophenotypic features, EBV infection status, clinical therapy and overall survival. Results: The median age of the patients of MCCHL-R was 28.5 years(range: 9-76 years, male∶female=1.6∶1.0). Twenty-seven patients(50.0%) had B symptoms. Most patients had cervical lymph node involvement(81.5%, 44/54). Mediastinum and spleen involvement were seen in 69.2%(36/54) and 24.1%(13/54), respectively. Extranodal non-lymphoid organ involvement was seen in 41.3%(19/46) cases. Morphologically, lymph node architectures were effaced at various degree with large neoplastic cells of variable morphology, including Hodgkin/Reed-Sternberg(H/RS) cells and anaplastic large cells. There were abundant background heterogeneous admixtures of non-neoplastic inflammatory and accessory cells that were predominant mature small lymphocytes. All tumors were positive for CD30 and weakly positive for PAX5. Epstein-Barr encoded RNA(EBER)detectable by in situ hybridization was seen in 39.0% cases. Forty-six patients had a median follow-up time of 32.5 months(range: 5-128 months) and the 5-year survival rate for stage Ⅰ-Ⅱ and stage Ⅲ-Ⅳ patients were 91.7% and 50.1%, respectively(P<0.05). The 5-year survival rate for MCCHL-R was lower than typical MCCHL patients. Single factor analysis showed that age of >45 years, extranodal involvement and stage Ⅲ-Ⅳ were correlated with poorer 5-year survival rate(P<0.05). Multiple factors Cox proportional hazards regression showed that extranodal involvement was the independent prognostic factor(RR: 4.352, 95%CI: 1.122-16.879, P<0.05). Conclusions: MCCHL-R is more common in young people. The tumor has pathological features of classic Hodgkin lymphoma enriched with the tumor cells(>10%) and similar immunophenotype to classical Hodgkin lymphoma. Compared with typical MCCHL, extranodal disease is an independent prognostic factor of MCCHL-R.