AN INTRAPULMONARY MASS: A RARE PRESENTATION OF CASTLEMAN DISEASE

Abstract

SESSION TITLE: Lung Pathology 2 SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/09/2018 01:15 PM - 02:15 PM INTRODUCTION: Castleman disease (CD) is a lymphoproliferative disease clinically classified as unicentric or multicentric. Histologically, CD has two variants: hyaline vascular and plasma cell type. Unicentric CD (UCD) is commonly found in the mediastinum and is usually of the hyaline vascular subtype. CD presenting as an intrapulmonary mass is very rare with only a few reported cases. We present a patient with intrapulmonary Castleman disease (IPCD). CASE PRESENTATION: 31 year old male, non-smoker, with no past medical history who presented with pleuritic chest pain. Chest radiograph revealed a 7.7 cm right infrahilar mass. CT of the chest revealed a 5.6x4.2x3.3 right infrahilar partially calcified mass complicated by a right lower lung collapse and nodular opacities (see image 1 and 2). Infectious workup and tumor makers HCG/AFP/LD were negative. Subsequent PET/CT showed low to moderate FDG avidity. He underwent two separate bronchoscopies with transbronchial biopsies of the right middle lobe bronchus that were both non diagnostic. He then underwent CT guided biopsy that displayed lymphoid infiltrate, but was non diagnostic for lymphoid malignancy. Lastly, he underwent right thoracotomy with right middle and lower lobe resection. Pathology of the lung parenchyma was consistent with the hyaline vascular variant of CD. DISCUSSION: UCD is a rare disease that most commonly occurs in the thorax with nodal proliferation into any lymphatic tissue including: the hila, axillae, pleural space, chest wall and extrapleural soft tissues. IPCD is even rarer, with only a few reported cases in the literature. Histologically both IPCD and UCD are of the hyaline vascular variant. Further characterization of our patient's pathology also reveals large caliber airways, blood vessels, glandular tissue and cartilage, which suggests that the process originated in the peribronchial or peribronchiolar lymphoid tissue. While the pathogenesis of the disease has yet to be fully elucidated, the hyaline variant is generally less aggressive. The treatment of choice is surgical resection, which is usually curative. CONCLUSIONS: CD remains a diagnostic challenge as clinical presentation is variable, radiographic findings are nonspecific and an adequate sample for biopsy may be difficult to obtain. Surgical resection is typically both diagnostic and therapeutic. Given this complexity, it is essential to include CD in the differential for intrapulmonary masses. Reference #1: Kligerman S, Auerbach A et al. Castleman Disease of the Thorax: Clinical, Radiologic, and Pathologic Correlation: RadioGraphics. 2016;36(5):1309-1332. Reference #2: Liu Y, Chen G, Qiu X, et al. Intrapulmonary unicentric Castleman disease mimicking peripheral pulmonary malignancy. Thoracic Cancer. 2014;5(6):576-580. DISCLOSURES: No relevant relationships by Nader Kamangar, source=Web Response No relevant relationships by Maralee Kanin, source=Web Response