PULMONARY ROSAI-DORFMAN DISEASE WITH NO LYMPH NODE INVOLVEMENT

TOPIC: Lung Pathology TYPE: Fellow Case Reports INTRODUCTION: Histiocytosis is a disorder when collection of hematopoietic-derived cells multiply without regulation but not considered malignant. The most recent classification was laid out by the World Health Organization in 2016 dividing them into multiple groups. Rosai-Dorfman disease typifies R group and unique its presentation ranging from solitary lesion or multifocal, systemic disease. CASE PRESENTATION: A 74-year-old male African descent with past medical history significant for tobacco abuse presented to emergency department hemoptysis that started 2 days prior presentation. Patient seen as outpatient due CT chest showed 4.2 cm mass left lower lobe, no lymphadenopathy; confirmed another Chest department. PET/CT at time had increased 18-FDG uptake SUV 26.4. There very high suspicion lung carcinoma bronchoscopy friable, bleeding, pedunculated occupying LLL basal segmental airway. removed using snare forceps tumor base cauterized argon plasma coagulation. report proliferation histocytes immunostaining positive S100 CD68, negative CD1a consistent diagnosis patient on definitive radiation therapy resolution his symptoms. DISCUSSION: (RDD) rare histiocytosis characterized being multisystemic. First described 1969 Rosai Dorfman, this self-limiting painless lymph node enlargement teenagers young adults. Our late 70's descent. Recent publications coming China 25 cases RDD extranodal less common Asians compared white/black patients, mean age 45 years old. Pulmonary involvement usually involves mediastinal lymphadenopathy which our did have; limited lobe. Differentiating malignant disease, especially smoking history, challenging. Histopathology will give - S-100 CD68 are markers ruling Langerhans cell histiocytosis. Treatment localized disease-causing symptoms, has good response CONCLUSIONS: present lungs alone difficult differentiate malignancy. Diagnosis based tissue sampling immunohistochemistry staining (+) (-) CD1a. Radiation an effective treatment symptomatic REFERENCE #1: Abla O, Janka G. Histiocytic Disorders Cham: Springer International Publishing AG; 2017:30-33 #2: Ali A, Mackay D. lung. Thorax. 2009;64(10):908-909 #3: Kong Y, J, Shi D et al. Cutaneous clinical histopathologic study China. American journal surgical pathology. 2007;31(3):341-350 DISCLOSURES: No relevant relationships Alfredo Iardino, source=Web Response Jill Ono, Arthur Oliver Romero, Ipsita Samanta,