An 86-year-old New Zealand European white man was diagnosed as having smoldering myeloma of IgA lambda subtype in June 2008. His diagnostic bone marrow aspirate showed 38% plasma cells. His paraprotein at diagnosis was 9 g/L and gradually increased to 46 g/L by mid-2016 without any evidence of end organ damage (Fig. 1).
His other medical history includes L2–3, L5–S1 spondylosis and early stage prostate adenocarcinoma, T2A Nx M0, Gleason grade 6, which was successfully eradicated with radical radiotherapy in 2000. He takes cholecalciferol 1.25 mg once monthly, cilazapril 2.5 mg daily, amitriptyline 10 mg daily, and paracetamol 1 g twice daily and is intolerant of Augmentin (amoxicillin-potassium clavulanate; diarrhea). He lives with his wife and is fully independent with all his activities of daily living. He does not smoke tobacco and he consumes two units of alcohol per day.
In June 2016, he developed mild normochromic anemia of 104 g/L and 6 weeks later he was hospitalized with melena in the context of recent non-steroidal anti-inflammatory drug (NSAID) use for low back pain. No bleeding source was identified on upper and lower endoscopies. The ibuprofen was stopped and he was started on omeprazole. He was also found to be mildly vitamin B12 deficient with a raised methylmalonic acid, and was commenced on vitamin B12 treatment. His hemoglobin fell to a nadir of 72 g/L during the NSAID-induced gastrointestinal bleed, but quickly recovered to its new baseline of 92–97 g/L and remained unchanged for the next 12 months. With regards to his back pain, a computed tomography (CT) skeletal survey and subsequent magnetic resonance imaging (MRI) of his lumbar spine showed mild osteoporotic compression fractures of L1–4 without any evidence of lytic disease. A follow-up bone density scan confirmed osteoporosis with a T-score of −2.7 in the left neck of his femur. He was treated with a single dose of zoledronic acid in August 2016 and a weaning course of analgesia. Concordant with his hemoglobin, his paraprotein remained stable at 45–50 g/L over the subsequent 12 months. Given the absence of other myeloma-defining events and unclear etiology of the anemia, he continued with watchful observation.
In August 2017, he was prescribed a 10-day course of roxithromycin 150 mg twice daily for a clinically diagnosed community-acquired pneumonia. He had presented to his general practitioner with a 10-day history of productive cough, malaise, and anorexia. His temperature was 37.4 °C, blood pressure 140/70 mmHg, heart rate 70 beats per minute, and O2 saturations 98% on room air. Focal crepitations were heard at his left base and the rest of his physical examination was unremarkable. On review 4 days later, he had clinically deteriorated with a temperature of 39.0 °C, blood pressure 140/70 mmHg, heart rate 100 beats per minute, and O2 saturations 97% on room air but his physical examination findings were otherwise unchanged. Cephalexin 500 mg twice daily for 1 week was added to his treatment regime. He completed full courses of both antibiotics with eventual complete recovery. No blood test or sputum sample was submitted to the laboratory, and a chest X-ray was not performed. He did not receive any corticosteroids or herbal remedies with his chest infection.
At his next routine hematology follow-up a week later, his paraprotein level (quantified by capillary electrophoresis) had decreased by 57% from 46 to 20 g/L. Over the next 4 months, while off all treatment, it slowly increased to 23, 26 then 28 g/L. Quantitative IgA levels demonstrated a similar pattern, falling from 54 to 22 g/L, before increasing to 27, 31 then 33 g/L. His hemoglobin increased from a pre-treatment average of 97 to 123, 126 then 132 g/L over the next 4 months. The rest of his laboratory parameters remained stable; his creatinine was 102 mmol/L, adjusted calcium 2.3 mmol/L, and albumin 32 g/L. Serum free light chains were not measured. When reviewed 4 months after the course of roxithromycin, he was asymptomatic apart from his chronic intermittent low back pain, which was improving.
His International Staging System was calculated as II in August 2016. Clearly, his myeloma had a favorable slow progressive phenotype, as evidenced by the prolonged latent phase (8 years) from diagnosis and the stability of symptoms and paraprotein despite being untreated.