Case Presentation: A 47-year-old body builder with a history of anabolic steroid use, five recent subcutaneous infections thought to be due to non-sterile street drugs, and recent development of CKD 2 was admitted for left lateral thigh cellulitis and mild AKI. Following IV antibiotic initiation, patient reported worsening leg pain. MRI of the leg identified a small abscess with incidental findings of bone marrow abnormalities, likely marrow hyperplasia consistent with known testosterone use. However, hemoglobin level was persistently low, ranging from 12.1 to 12.8 g/dL. Following aspiration of the abscess, infectious symptoms improved, though patient continued to report hip pain. Despite initial fluid resuscitation and good subsequent oral intake there was no notable improvement in renal function. Urinalysis was obtained, which showed isolated nephrotic-range proteinuria. In the setting of multiple abnormalities inconsistent with isolated infection, urine protein electrophoresis (UPEP) was ordered to evaluate for potential underlying plasma cell dyscrasia. This study was pending at the time of discharge and follow-up request was communicated to the outpatient provider via discharge summary.UPEP ultimately revealed an M protein spike with isolated elevation of lambda free light chains on immunofixation. Per independent chart follow-up several weeks post-discharge, it was noted that patient had presented to his PCP, but UPEP results were not addressed. Primary care provider was contacted to close the loop and serum protein electrophoresis was obtained. This confirmed M spike in the gamma fraction with lambda light chain elevation of 2.24 g/L and light chain ratio of 0.0037, consistent with diagnosis of multiple myeloma.
Discussion: Multiple myeloma (MM) is a relatively rare cancer and can be challenging to diagnose (1). Most patients are diagnosed between the ages of 65-75, but approximately 10% of patients are diagnosed before the age of 50 (2). Abnormalities that classically raise concern for MM include hypercalcemia, renal failure, anemia, and unexplained bone pain, which are seen in approximately 13%, 19%, 73%, and 79% of patients, respectively, at time of diagnosis (3). Recurrent or severe infection is not considered a typical feature of MM, yet these patients have a 5-fold increased risk of bacterial infection and a 7-fold increased risk of viral or fungal infections (4), amounting to a 16% risk of infectious complications at diagnosis (1).If there is suspicion for an underlying plasma cell dyscrasia, appropriate testing should not be delayed, as outcomes can improve with early diagnosis (6), but these tests can have a prolonged turn-around time. Importantly, approximately one third of all tests pending at hospital discharge return actionable results which can alter the post-discharge course (5). However, studies have shown that both inpatient and outpatient providers have poor awareness of the results of tests pending at discharge (7).
Conclusions: This patient presented with recurrent infections, recent development of renal impairment, AKI of uncertain etiology, proteinuria, and paradoxically low-normal hemoglobin leading to concern for plasma cell dyscrasia. Many of these abnormalities had been thought to be related to the patient’s muscle mass and steroid use, but inpatient admission provided an opportunity for comprehensive assessment, and he was ultimately diagnosed with MM through ongoing post-discharge follow-up and collaboration between the inpatient and outpatient physicians.