To Editor: Primary bone tumors of chest wall are rare, and near 50% are malignant.^1),(2 Solitary plasmacytoma is a rare condition that may affect bones or soft tissues, and can evolve to overt multiple myeloma if not early detected and controlled.^1),(2 Bone plasmacytoma often occurs in vertebrae, femur, iliac, sternum and ribs, and the outcomes are usually favorable if treated by surgery or radiotherapy.^1),(2 Authors call attention to differential diagnosis, including metastasis, sarcoma, lymphoma, neurectodermal and giant cell tumors, histiocytoma, chondroma, chondroblastoma, fibroma, fibrous dysplasia, and lipoma and bone infarction.²

Arévalo-Zamora et al. described a 55-year-oldman with long standing chest pain due to an unsuspected solitary plasmacytoma of the sternum, which was diagnosed by typical histology findings in bone marrow biopsy; in addition to normal levels of serum immunoglobulins and kappa and lambda light chains.¹ These features were consistent with the diagnosis of solitary plasmacytoma; and, in addition, the possibility of coexistent multiple myeloma was ruled out.^1),(2 The authors emphasized the lack of consensual procedures-either surgery or radiotherapy, for the best management of this scarcely reported condition.¹ They substituted the sternal body by a biological mesh, plus titanium bars; radiotherapy was utilized to treat a residual lesion showed by control images.¹ The authors believe that the approach reduces complications, yielding good quality of life;¹ therefore, their case report should stimulate confirmatory studies.

In this setting, I would like to comment the report by Santos et al. about rib plasmacytoma and overt multiple myeloma in a 65-year-old Brazilian woman.² The patient with uncontrolled hypertension and type 2 diabetes, had severe anemia, heart insufficiency, renal failure, hypercalcemia and hyper viscosity.² Further investigations showed monoclonal IgA/Kappa, 51% of plasmacytes in bone marrow, highly elevated beta-2 micro globulins, and a solitary osteolytic lesion disclosed in the right fourth rib by images of the computed tomography.² Unsuccessfully, the patient underwent three sessions of plasmapheresis and dexamethasone to control the hyper viscosity manifestations; after initial improvement, the patient died because of irreversible pulmonary acute edema. This debilitated old woman was considered to have a long standing undetected solitary rib plasmacytoma that might have evolved to a generalized myeloma.² The authors emphasized diagnostic challenges related to the co morbidities and the role of late diagnosis of plasma cell malignancies in the present case study.² Should the diagnosis of rib plasmacytoma be established in an earlier phase, the outcome of the patient would be favored by surgery and radiotherapy.^1),(2

The commented reports may enhance the suspicion about this rare bone tumor, and call attention to biological mesh plus titanium bars as good options.