Multicentric Castleman Disease: A Lymphoma Mimic in an Immunocompetent Patient.

SESSION TITLE: Cancer Case Report Posters ISESSION TYPE: Affiliate Case Report PosterPRESENTED ON: Tuesday, October 28, 2014 at 01:30 PM - 02:30 PMINTRODUCTION: Castleman's Disease (CD) is a rare lymphoproliferative disorder first reported by Castleman et al in 1956. Two forms have been described; localized unicentric disease and rare multicentric disease with involvement of multiple sites. Multicentric CD (MCD) is more commonly seen in immunosuppressed patients, especially in HIV and HHV 8 positive patients. Here we discuss the diagnostic challenge of a patient presenting with a large anterior mediastinal mass and rare HIV and HHV 8 negative multicentric CD.CASE PRESENTATION: A 46 year old female was referred to the pulmonary clinic with progressive shortness of breath and generalized edema. No prior pulmonary problems. Chest CT showed a large anterior mediastinal mass, multiple pleural parenchymal lung opacities, small left pleural effusion and axillary adenopathy. CT guided biopsy of the mass showed sclerosing mediastinitis. PET scan noted hypermetabolic activity in the anterior mediastinal mass, tonsils, spleen and supraclavicular and axillary adenopathy. Labs revealed hemoglobin of 7.9 mg/dl, platelets 72000/ uL. Highly concerned for a lymphoma, bone marrow biopsy was done showing erythroid hyperplasia. Worsening symptoms and a working diagnosis of lymphoma prompted axillary lymphnode excision, pathology confirmed plasma cell variant of CD. HIV and HHV 8 negative. Treated with four weekly cycles of etoposide and rituxan leading to regression of mass and clinical improvement.DISCUSSION: MCD is a systemic disease with generalized lymphadenopathy, hepatosplenomegaly, edema, fevers and night sweats; Strongly associated with HIV and HHV 8 infection. Pulmonary symptoms cough and dyspnea are associated with pulmonary interstitial lymphocytic and plasma cell infiltrates Pathogenesis is unclear and linked to excessive release of IL-6 or related peptides. Two histological variants recognized; hyaline vascular and plasma cell. Plasma cell variant is more common in MCD and the lymphnode biopsies show reactive lymphnode follicles and interfollicular plasmacytosis. Treatment options include inhibition of IL-6, anti- CD 20 monoclonal antibody, steroids and cytotoxic chemotherapy (Etoposide). HIV and HHV-8 negative patients have better prognosis.CONCLUSIONS: MCD can occur in HIV and HHV 8 negative patients and could be misdiagnosed if not suspected in patients with mediastinal mass. Lymphnode excision is often necessary for confident pathological diagnosis.Reference #1: Castleman et al Localized mediastinal lymph node hyperplasia resembling thymoma Cancer, 9 (1956), pp. 822-830DISCLOSURE: The following authors have nothing to disclose: Deepa Kuchelan, Sameh AzizNo Product/Research Disclosure Information.