A case of synchronous dual hematological malignancy: effects of multiple myeloma therapy on essential thrombocythemia and vice versa
Nupur Krishnan1, Russell Price2, Rouslan Kotchetkov 2*
1 University of Western Ontario, 1151 Richmond St, London, ON, N6A 3K7; Canada
2 Simcoe Muskoka Regional Cancer Program; Royal Victoria Regional Health Centre, Barrie, ON, Canada, L4M 6M2
Short Title: Synchronous MM and ET
*Correspondence: KotchetkovR@rvh.on.ca
Rouslan Kotchetkov
Department of Oncology, Simcoe Muskoka Regional Cancer Program; Royal Victoria Regional Health Centre, Barrie, ON, Canada, L4M 6M2
Tel: +1-705-728-9090
Number of Tables: 2
Number of Figures: 2
Word count: 1780
Keywords: Essential Thrombocythemia, Multiple Myeloma, Dual Hematological Malignancies
Abstract
We present a case of synchronous dual hematological malignancies: multiple myeloma (MM) and masked essential Thrombocythemia (ET). Excessive thrombocytosis due to bone marrow recovery occurred during anti-myeloma therapy. Treatment for MM had no effect on ET; concomitant ET did not decrease the efficacy of anti-myeloma therapies in this frail patient.
Introduction
Dual malignancies occurring in the same patient are reported in the literature [1]; however, dual hematological malignancies (DHMs) are recognized less frequently [2-5] and are likely underreported [6]. DHMs can been classified as either synchronous (SDHMs), when occurring within six months of diagnosis of the first malignancy, or asynchronous when occurring later [1]. Using a more restrictive cut off of one month, we had earlier reported a 1.5% incidence of SDHMs in patients referred to our cancer center [6]. The detection of DHMs may be an incidental finding during routine bloodwork or during investigation of discrepant clinical and laboratory findings [6]. The observed underreporting, and potential under detection, of SDHMs may be because of masking from the primary malignancy [6]. DHMs involving essential thrombocythemia (ET) and multiple myeloma (MM) are quite uncommon, and most cases report MM developing years after ET diagnosis. The occurrence of these two malignancies synchronously is extremely rare. We report a case of concurrent MM and ET in a frail elderly patient. We review the literature, discuss possible mechanisms, and present potential challenges in the management of such patients.
Patient Information/ Clinical Findings
An 86-year-old female presented to the emergency in May 2016 with confusion, hypercalcemia, and acute kidney injury. Her past medical history included hypertension, hyperlipidemia, and osteoporosis. She was brought to the clinic on a stretcher with an Eastern Cooperative Oncology Group (ECOG) status of 4. On examination, she was disoriented and had tenderness along her left rib cage. Investigations showed hemoglobin (Hb) 82 g/L, macrocytosis (MCV 134), rouleaux, WBC 4.2 x109 with normal differential, and platelets 226 x 109/L (shown in Fig. 1A). Chemistry showed total protein 99 g/L, albumin 26 g/L, calcium 3.15 mmol/L, and creatinine clearance 17 mL/min. Total IgG was elevated (45.9 g/L) with reciprocally decreased IgA and IgM. Monoclonal Protein (MP) was 41.8 g/L. Free Light Chain (FLC) lambda was elevated (9,050 mg/L). Skeletal survey showed osteopenia and a T12 vertebral compression fracture. Bone marrow (BM) examination showed infiltration by plasma cells comprising up to 90% of nucleated cells including occasional binuclear and atypical plasma cells (PC) (shown in Fig. 1B). The PC were kappa restricted and had strong cytoplasmic CD138+ expression (shown in Fig. 1C). Erythroid and megakaryocytic maturation was reduced but normal morphologically.