An Unexpected Clinical Outcome Following a Lung Nodule

Abstract

SESSION TITLE: Lung Pathology 2 SESSION TYPE: Affiliate Case Report Poster PRESENTED ON: Tuesday, October 31, 2017 at 01:30 PM - 02:30 PM INTRODUCTION: Crystal-storing histiocytosis (CSH) is a rare pathology that has been commonly associated with an underlying neoplasm. On imaging, CSH may present as a well circumscribed tumor-like nodule without lobar predilection. CASE PRESENTATION: A 70-year-old male patient, former smoker, was found with a spiculated nodule (0.7cm x 0.9 cm) at the right lung base on a routine chest x-ray. Due to risk factors, as recommended by guidelines, the patient underwent nodule follow-up. Evaluation in one year showed that this former nodule increased in size. PET CT scan showed a new ground glass moderate hypermetabolic lesion at the right upper lobe measuring 2.6 cm as well as the previously described right lower lobe node. A CT guided right upper lobe lesion biopsy was performed by interventional radiology and pathology analysis showed increased number of plasma cells, small T-cells, and histiocytes confirming a diagnosis of crystal-storing histiocytosis. Hemoglobin level, renal function, and electrolyte levels were within normal limits. SPEP showed no M-spike but peripheral blood free kappa/lambda ratio was 2 (normal 1:1.5). Bone marrow biopsy was performed showing no evidence of increase in plasma cells or histiocytes but positive fluorescent in situ hybridization for monosomy 13 and t(11;14). An underlying malignancy was not found during initial evaluation and he continued under surveillance. One year later, the patient developed anterior neck discomfort. Further evaluation showed a 2.0 cm dominant mass lesion at the lower aspect of the left thyroid lobe. Biopsy of the thyroid mass was consistent with medullary thyroid carcinoma (MTC). DISCUSSION: CSH is defined as a proliferation of histiocytes that contain numerous immunoglobulin crystals. CSH is a rare process most often occurring in conjunction with an underlying hematopoietic neoplasm, usually low grade B cell lymphoma or multiple myeloma (MM). CONCLUSIONS: This case highlights the relevance of malignancy surveillance in patients presenting with CSH and the need to pursue a final diagnosis among these patients. Furthermore, to our knowledge there is no prior documented association of CSH with MTC in the literature. Reference #1: Ionescu DN, Pierson DM, Qing G, et al. Pulmonary Crystal-Storing Histiocytoma. Arch Pathol Lab Med 2005;129(9):1159-63. DISCLOSURE: The following authors have nothing to disclose: Javier Ramos-Rossy, Yomayra Otero, Francisco Del Olmo, Edgardo Adorno, Onix Cantre-Fonseca, William Rodriguez-Cintron No Product/Research Disclosure Information