HL-367 ASCT for Treatment-Resistant Mediastinal Gray Zone Lymphoma

Abstract

Gray zone lymphoma (GZL) is a rare type of blood cancer with intermediate characteristics of diffuse large cell B lymphoma (DLCBL) and classical Hodgkin lymphoma (cHL). There is no universal approach to the management of GZL, and resistant cases often remain challenging. To describe a potential treatment for mediastinal GZL (MGZL) resistant to standard chemotherapy regimens based on a clinical case report. A 40-year-old woman was admitted to the hospital with recent onset of generalized itchiness, weakness, fevers, and night sweats. Upon initial standard workup, a CT scan demonstrated a 7 × 4 cm mediastinal mass with irregular borders and several enlarged paraaortic (2 cm), parasternal (4 cm), and aortic bifurcation (2 cm) lymph nodes. The excision biopsy specimen from the mass showed high expressivity of CD30 and moderate expressivity of CD20, CD3, MUM-1, Fascin, and CD79a, with Ki67 detected in 75%-80%. CD15, AE1/3, ALK, PAX-5, CD45, CD19, CD 23, CD68, BOB 1, and PD-1 were negative. The patient was diagnosed with stage IIB MGZL with intermediate features of DLCBL and cHL. Interventions and Main Outcomes: Initial treatment with the R-BEACOPP regimen resulted in some shrinkage in lymph node sizes; however, after the fourth cycle of chemotherapy, a PET-CT scan demonstrated disease progression with Ds5 metabolic activities in the left axillary, mediastinal, and bronchopulmonary nodes, along with left lung consolidation. Salvage therapy with 2 courses of R-DHAP regimen was administered without significant success, as the consequent CT scan demonstrated a tumor size of 9.4 × 5.9 × 7.6 cm with extension to the left lung. This was followed by 3 cycles of BV, resulting in 3-4 months of disease remission. Due to subsequent disease progression, 2 cycles of BvB and 2 cycles of BV-ICE were initiated, followed by autologous stem cell transplantation (ASCT). The procedure resulted in pancytopenia and oral mucositis, both of which were resolved with appropriate treatment. The patient is currently in the third week of follow-up for further management. ASCT may ultimately be a candidate for treatment-resistant MGZL. These findings should be validated in larger studies.