Rapid response of plasmacytomas to lenalidomide plus low‐dose dexamethasone therapy in a patient with relapsed multiple myeloma
Authors: Toshihiro Fukushima, Takuji Nakamura, Haruka Iwao, Hisanori Umehara
Journal: American Journal of Hematology (2011)

Plasmacytomas have sometimes been seen at the time of diagnosis or during the course of multiple myeloma (MM) [1, 2]. Although the development of multiple plasmacytomas is considered to be associated with aggressive disease and poor prognosis of MM [2], a strategy for MM with multiple plasmacytomas has not been established. Herein, we present a relapsed MM patient who achieved a rapid response of plasmacytomas to lenalidomide plus low-dose dexamethasone (Rd) therapy. A 57-year-old Japanese woman was diagnosed immunoglobulin G lambda-type MM in July 2003. Abnormal cytogenetics including 13q-/-13 were not detected in metaphases. She achieved a complete response with three courses of ranimustine, vincristine, melphalan, and dexamethasone (ROAD) therapy and five courses of bortezomib-based therapy, at diagnosis and at first relapse in 2009, respectively. In December 2010, 7 months after the last chemotherapy, she complained of painless tumors of the head, numbness of the left leg and lumbago. Her serum β2-microglobulin was elevated (5.0 mg/l) and IgA and IgM were suppressed (67 and 33 mg/dl, respectively) while her IgG was normal (1,040 mg/dl). Her hemoglobin and serum albumin were 10.9 and 3.4 g/dl, respectively. Computed tomographic (CT) scan showed three skull tumors (5.0 cm × 3.5 cm, 2.5 cm × 0.5 cm, and 1.5 cm × 0.5 cm, Fig. 1A). 18FDG-PET/CT scan showed systemic multiple positive lesions, including three skull tumors and systemic bone and bone marrow. She was therefore diagnosed with second relapse of MM with multiple plasmacytomas. Although bortezomib-based multidrug combination therapies are recommended for MM with multiple plasmacytomas [3], we decided on Rd therapy with 40% dose reduction of lenalidomide because she had a history of discontinuation of chemotherapy due to severe adverse events. Lenalidomide (15 mg) and dexamethasone (10 mg) were administered orally on days 1–21 and on days 1, 8, 15, and 22 of each 28-day cycle, respectively. A CT scan on day 20 of the first course of Rd therapy revealed complete disappearance of plasmacytomas of the skull (Fig. 1B). Numbness of the left leg and lumbago also disappeared after the first course of Rd therapy. To date (June 2011), six courses of Rd therapy have been administered without ≧Grade 3 adverse events and she has been symptom free. Although thalidomide has been considered ineffective for plasmacytomas [2, 4] and lenalidomide is an analog of thalidomide, some reports have mentioned the efficacy of lenalidomide for MM with multiple plasmacytomas [5-9]. Antiangiogenic efficacy of lenalidomide is stronger than that of thalidomide [10], which may be one of the reasons for the clinical efficacy of lenalidomide for plasmacytomas because plasmacytomas have increased angiogenic activity [11]. Furthermore, a rapid response for plasmacytomas and rapid disappearance of symptoms associated with MM suggest that lenalidomide may have direct antiproliferation mechanisms for myeloma cells. In conclusion, this case report indicates that lenalidomide may be a promising agent and Rd therapy may be one of the options for MM with multiple plasmacytomas. Prospective trials should be conducted to confirm the efficacy of lenalidomide-based therapy for MM with multiple plasmacytomas. CT scan before (A) and on day 20 of the first course of lenalidomide plus low-dose dexamethasone (Rd) therapy (B). Arrow indicates plasmacytoma at the parietal bone. Plasmacytoma disappeared completely during the first course of Rd therapy. Toshihiro Fukushima*, Takuji Nakamura*, Haruka Iwao*, Hisanori Umehara*, * Department of Hematology and ImmunologyKanazawa Medical University, Ishikawa, Japan.