Case Presentation: A 39-year-old Hispanic man presented with four weeks of dry cough. The cough was associated with minimal dyspnea on exertion, low grade intermittent fevers, back pain and pleuritic chest pain related to frequent coughing, and recent unintentional weight loss of 20 pounds over 2 months due to anorexia. Patient denied dyspnea at rest, night sweats, fatigue, recent travel or recent incarceration, or sick contact. Physical exam was unremarkable except for conjunctival pallor. Labs were significant for: Hemoglobin 5.9 g/dl, Hematocrit 19.6%, MVC 96.6, MCH 29.1pg, MCHC 30.1g/dl, reticulocyte 3.8%, and peripheral smear revealed rouleaux formation. While WBC with differentials, Basic Metabolic panel including Calcium, Creatinine, and Urine studies were unremarkable including undetected urine protein on admission. However, patient was found to have a higher total protein to albumin gap of 12.4 g/dl, further investigations revealed kappa/lambda ratio 17, beta-2 microglobulin of 4.9 mg/L. Serum protein electrophoresis and immunofixation did not demonstrate a monoclonal spike. Skeletal survey revealed diffuse lytic lesions in the axial and appendicular skeleton. We proceeded with Bone marrow biopsy which revealed 78% plasma cell population, and fluorescence in-situ hybridization revealed hyperdiploid clone. Patient was started on chemotherapy for Multiple myeloma with lenalidomide 25 mg daily, 3 weeks on and one week off.
Discussion: Multiple Myeloma (MM) is a disease of older adults with mean age of 68 years old. MM occurs in all races, but the incidence is variable by ethnicity: higher in African Americans, while lower in Mexicans and Japanese. While some cases appear to be familial, there are studies showing an increased incidence of MM with occupational exposure. This is a case of a young patient with non-measurable free light chain only MM that is very rare in patients younger than 40 years of age. Our patient did not have risk factors for MM given his young age, Mexican heritage, and lack of family history. His painting occupation, however, is a concerning risk factor for occupational exposure leading to MM.
Conclusions: Few case reports have suggested a higher incidence of MM in patients with Chlorinated solvent exposure, which is commonly found in paint thinners. This relationship is however not well studied. This case serves to make hospitalists aware to consider MM in young patients with appropriate clinical suspicion and laboratory findings, especially assessing occupational risk factors.