SESSION TITLE: Pulmonary Manifestations of Systemic Disease Student/Resident Case Report Posters II SESSION TYPE: Student/Resident Case Report Poster PRESENTED ON: Tuesday, October 27, 2015 at 01:30 PM - 02:30 PM INTRODUCTION: Mantle Cell Lymphoma (MCL) is a B cell malignancy. Crystal-Storing Histiocytosis (CSH) is a rare, benign entity suggesting the presence of underlying lymphoproliferative disorders. Neither is commonly identified in the trachea. We present a woman with significant dyspnea with CSH in the distal trachea, and co-existing subglottic MCL. CASE PRESENTATION: A 68 year old female avid biker, with a 25 year history of relapse-free CLL, with multiple prior therapies and splenectomy, presented with a six month history of progressive dyspnea, unable to climb 4 stairs. CT angiogram was negative for PE or progressive adenopathy, but upon re-review demonstrated stable thickening of the distal trachea, present since 2009. PFTs suggested a fixed large airway obstructive process. Echocardiogram was negative, and exercise ECG was limited by dyspnea without evidence of cardiopulmonary abnormality. Bronchoscopy revealed an infiltrative process markedly narrowing the subglottic area, as well as a separate lesion involving the distal trachea. Two days after bronchoscopy she was admitted with stridor, placed on steroids and underwent subglottic debulking with dramatic symptomatic improvement. Pathology revealed MCL in the subglottic region and CSH in the distal trachea. Bone marrow biopsy revealed no involvement, and PET CT only demonstrated FDG avidity in the subglottic and distal tracheal areas. She was initiated on rituximab and bendamustine with good response. DISCUSSION: MCL represents 7% of all adult forms of non-Hodgkins Lymphoma with a median age of onset in the 60s. Most patients are in advanced stages at diagnosis primarily presenting with lymphadenopathy, though MCL can present in a single non-lymphoid organ. The disease is typically aggressive with a median survival of 3 years, though a smaller subset of patients survives for years with stable disease. Though CSH is benign, it usually represents the presence of underlying hematologic malignancies, and when discovered necessitates exploration for the malignant source. Lung involvement of CSH is well described. To our knowledge, this is the first case report of CSH associated with MCL, and the first of CSH in the trachea. CONCLUSIONS: It is likely, upon re-review, that our patient has had indolent MCL throughout the course of her disease and not CLL. Her subglottic lesion likely represents a symptomatic recurrence of MCL. Presumably the stable thickening in the distal trachea, previously thought to be inflammation induced from intubation, had long been CSH from her underlying MCL. Had her subglottic lesion been identified first, the distal tracheal lesion would have been considered a metastatic lesion, and the rare CSH-MCL association would have been missed. Reference #1: Guddati AK, et al. Primary mantle cell lymphoma of the trachea. Medical oncology 2012; 29:2385-2387 Reference #2: Lee JS, et al. A challenging diagnosis: crystal-storing histiocytosis in plasma cell myeloma. American journal of clinical pathology 2015; 143:300-304 DISCLOSURE: The following authors have nothing to disclose: Amanda McCambridge, Finbar Foley, Ryan Kern, Timothy Call, Eric Olson No Product/Research Disclosure Information