A 76-years-old female was diagnosed with multiple myeloma, immunoglobulin G (Ig-G), λ type. There was not involvement of the rib at the time of initial presentation. She was initially treated with bortezomib, 1.3 mg/m² once weekly, for five months, with the effect of lowering IgG. However, it was stopped due to peripheral neuropathy. Anemia, bone pain including pain at the rib tumor (Figure 1), renal impairment, and an increase in IgG appeared nine months later (Table 1). She was treated with lenalidomide and dexamethasone (DXA) for two weeks, which were stopped due to skin eruption, and subsequently with pomalidomide and DXA for two months, and a visible therapeutic effect of a tumor size decrease (Figure 2), as well as markedly lowering IgG and bone marrow plasma cells (Table 1), were observed.

Plasmacytoma of the rib is observed as solitary or a tumor after progression of multiple myeloma. It was hitherto treated with surgical resection, radiation, systemic chemotherapy before or after surgical resection including alkylating agents, anthracyclines, vinca alkaloids, steroids, and bone marrow transplantation [1][2][3]. In last decade, the treatment of multiple myeloma has greatly improved by the introduction of novel agents, including proteasome inhibitors (PI) and immunomodulatory drugs (IMiDs) [4]. In the present patient remarkable effect on rib tumor was observed after administration of IMiDs. These novel treatments should be tried before surgical resection.

A visible effect on a rib tumor in multiple myeloma was observed on administration of the recently developed immunomodulatory drugs.

Keywords: Immunomodulatory drugs (IMiDs), Multiple myeloma, Rib tumor

1. Hirai S, Hamanaka Y, Mitsui N, Uegami S, Matsuura Y. Multiple myeloma presenting as a solitary tumor of the rib; report of a case. [Article in Japanese]. Kyobu Geka 2008 Sep;61(10):899–901.   [Pubmed]    
2. Kodate M, Takagishi T, Osaki T. Plasmacytoma of chest wall. [Article in Japanese]. Kyobu Geka 2010 Sep;63(10):879–82.   [Pubmed]    
3. Santos VM, Brito EF, Paz BC, Leal CT. Rib plasmacytoma and IgA multiple myeloma with hyperviscosity syndrome. Arch Iran Med 2012 Aug;15(8):517–9.   [CrossRef]   [Pubmed]    
4. Kint N, Delforge M. Concise review - Treatment of multiple myeloma in the very elderly: How do novel agents fit in? J Geriatr Oncol 2016 Sep;7(5):383–9.   [CrossRef]   [Pubmed]