Iatrogenic immunodeficiency‐associated lymphoproliferative disease of the Hodgkin lymphoma‐like variant in a patient treated with mycophenolate mofetil for autoimmune hepatitis

Immunodeficiency-associated lymphoproliferative disorders (ILDs) are well-described entities that occur in the setting of organ transplant, bone marrow transplant, and congenital or acquired immunodeficiency [1, 2]. The latest World Health Organization (WHO) classification of tumors of hematopoietic and lymphoid tissues [3] defines a subset of “other iatrogenic ILDs”, composed mostly of lymphoproliferations occurring in the setting of patients receiving immunosuppressive therapy (particularly methotrexate or anti-TNF (tumor necrosis factor) agents) for autoimmune diseases or conditions other than in the transplant setting such as rheumatoid arthritis [4-9] or inflammatory bowel disease [10]. The role of Epstein-Barr virus (EBV) in ILDs is well characterized and the EBV-positive ILDs have a better prognosis than their EBV negative counterparts [9]. Among the morphologic variants of iatrogenic ILDs are classical Hodgkin lymphoma (cHL) and Hodgkin-like lymphoproliferations resembling cHL. These are rare entities with very few cases reported in the medical literature [4, 8, 11, 12]. We report a case of EBV-positive ILD of the Hodgkin-like variant in a patient on long-term mycophenolate mofetil (MMF) for autoimmune hepatitis. Our patient had a complete response after withdrawal of immunosuppression and treatment with rituximab. As many of these cases will resolve without cytotoxic chemotherapy, this case highlights the importance of recognizing this clinical entity [4] and distinguishing it from de novo lymphomas. A 42-year-old woman with a history of autoimmune hepatitis on immunosuppression since the age of 19 was referred for evaluation of a mandibular growth. The hepatitis had been controlled with prednisone and azathioprine for 20 years. Azathioprine and prednisone were then discontinued and the patient was treated with MMF (1,500 mg twice daily) for the past 3 years. Two months prior to presentation, she developed low-grade fevers, drenching night sweats, 2.5 kg weight loss, and painful, indurated, and ulcerated lesions of the right mandiblular, and maxillary gingivae (Fig. 1). All oral presentations began as small lesions that gradually increased in size and severity. Pertinent tests included hemoglobin of 10 g/dL, normal white blood cell count, normal platelet count, elevated erythrocyte sedimentation rate (ESR) (57 mm/hr), and normal lactic dehydrogenase. The biopsy from the buccal and lingual lesion revealed ulceration of the mucosa and infiltration of the submucosa with mononuclear and rare binucleated large cells with prominent single nucleoli. Figure 2 shows an extensive polymorphic infiltrate consisting of large R-S (Reed-Sternberg)–like cells with prominent nucleoli in a background of small to intermediate sized lymphocytes and histiocytes (Fig. 2A,B). The large atypical R-S–like cells (Fig. 2C) are CD30 positive with membrane and Golgi region–staining and are also dim nuclear PAX-5 and CD20 positive (Fig. 2D,E). R-S–like cells and scattered lymphocytes show positivity for EBV-encoded RNA (EBER) (Fig. 2F). This is consistent with a Hodgkin-like iatrogenic immunodeficiency-associated lymphoproliferative lesion. Indurated and ulcerated lesions of the right mandibular and maxillary gingivae. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.] Hodgkin-like iatrogenic limmunodeficiency-associated lymphoproliferative lesion. A, B: Biopsy from the buccal and lingual lesion shows an extensive polymprophic infiltrate consisting of large R-S–like cells with prominent nucleoli in a background of small- to intermediate-sized lymphocytes and histiocytes. C: The large cells R-S–like cells are CD30 positive with membrane and Golgi region staining and (D and E) are also dim nuclear PAX-5 and CD20 positive. F: R-S–like cells and scattered lymphocytes show positivity for EBV-encoded RNA (EBER). [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.] Combined PET/CT scan revealed fluorodeoxyglucose-avid lesions in the right maxilla and mandible, hilar and pelvic lymph nodes, lung parenchyma, and gastric wall. In the proper clinical setting, these findings are diagnostic of iatrogenic ILD, Hodgkin-like subtype. Clinical management consisted of interruption of MMF therapy and administration of rituximab 375 mg/m2 weekly for 4 weeks. On the second week of therapy, a significant reduction in size of the oral lesions was noted, and on the sixth week, a complete response was documented by physical exam (Fig. 1) and normalization of PET/CT scan. Hepatic enzymes were monitored weekly and no abnormalities were found despite the interruption of immunosuppression. The term post-transplantation lymphoproliferative disorders (PTLD) indicates the most common clinical setting for ILDs. PTLDs are often an EBV-driven monoclonal or polyclonal proliferation of B cells or less often T cells [13]. Immunosuppressants used to prevent graft rejection also result in relaxation of the immune surveillance provided by T cells over EBV-infected immortalized B cells allowing their uncontrolled and autonomous proliferation.14 The latest WHO classification [3] recognizes the occurrence of ILDs not only in post transplant settings but also in patients undergoing prolonged immunosuppression for autoimmune diseases. Several morphological subtypes occur in this setting such as atypical polymorphous lymphoproliferative disorders, diffuse aggressive non-Hodgkin lymphoma, Hodgkin lymphoma, and Hodgkin lymphoma–like lesions [15]. The latter subtype is one of the rarest morphologies, being EBV+ and CD30+ which is unlike classical Hodgkin lymphoma where only 20–40% of cases are CD20+, the R-S cells show variable stain intensity, and only a subpopulation of cells are CD 20+. We report a case of ILD, Hodgkin lymphoma–like subtype occurring in a patient after prolonged use of MMF for treatment of autoimmune hepatitis. This case represents a rare variation of an uncommon disease. Only a few cases of MMF-related ILDs have been reported in the literature, predominantly EBV-positive primary central nervous system (CNS) diffuse large B-cell lymphoma (DLBCL) [16]. To our knowledge, this is the first case reported of MMF-related ILD with Hodgkin lymphoma–like histology. This rare morphologic variant has also been reported following liver transplantation, being characterized by abnormal cells that exhibit features similar to classic R-S cells [17]. Kamel et al. reported a series of eight patients with this morphology: four with lymphoproliferative disease that resembled cHD and four cases diagnosed as HD associated with immunodeficiency. The cases developed in patients on methotrexate for rheumatoid arthritis, psoriasis, or polymyositis and all but two resolved when methotrexate was stopped. Rituximab, a monoclonal antibody directed against the cell surface antigen CD20, is not used to treat classic HL. However, in the setting of umbilical cord blood transplantation, preemptive treatment with rituximab has been shown to control EBV-driven B cell proliferation resulting in decreased incidence of PTLD [18]. In a much more frequent scenario, rituximab can induce durable complete responses in EBV-driven PTLD [19]. This case illustrates how the principles learned from the management of PTLD can be successfully extrapolated to the treatment of the less common iatrogenic ILDs. It also demonstrates how clinical manifestation can potentially present in less common sites. Withdrawal of the immunosuppressant when possible and accurate histological diagnosis, are keystones of successful management without cytotoxic treatment. Betsy Adams*, John Lazarchick , Ana Maria Medina , Ira R. Willner , Brad Neville?, Edward Murphy?, Robert Stuart*, Luciano J. Costa*, * Medical University of South Carolina, Department of Medicine, Division of Hematology/Oncologyl, Charleston, South Carolina, Medical University of South Carolina, Department of Pathology, Charleston, South Carolina, Medical University of South Carolina, Department of Medicine, Division of Gastroenterology and Hepatology, Charleston, South Carolina, ? Medical University of South Carolina, College of Dental Medicine, Department of Stomatology, Division of Oral Pathology, Charleston, South Carolina, ? Medical University of South Carolina, College of Dental Medicine, Department of Stomatology, Division of Periodontics, Charleston, South Carolina.