The authors on “Solitary Extramedullary Plasmacytoma of the Bladder” have provided a quick and accurate diagnosis, work-up, and treatment of this solitary extramedullary plasmacytoma. Solitary extramedullary plamacytomas are rare, and account for only 3% of all plasma cell malignancies. Of the 3% of plasma cell malignancies that are diagnosed, the bladder is one of the least common locations. The rarity of the tumor frequently makes the process of making a correct diagnosis difficult. After making the diagnosis with immunohistochemistry, a bone marrow biopsy must be performed to rule out multiple myeloma. Additionally, a body and skeletal survey must show no evidence of additional disease or lytic lesions in order to confirm localized disease. In this case, these procedures were performed accurately and in a timely fashion.
While there are few reported cases of solitary extramedullary plasmacytoma of the bladder, overall, when radiotherapy is used as it was in this case and delivered with curative intent (median dose, 50 Gy), few patients develop local recurrences or progress to develop multiple myeloma. Lenalidomide (CC-5013, a derivative of thalidomide(Drug information on thalidomide) that was introduced in 2004 and marketed as Revlimid by Celgene) is an immunomodulatory, antiangiogenic, and antineoplastic drug that is a potent inhibitor of tumor necrosis factor-alpha secretion. Lenalidomide enhances cell-mediated immunity through anti-CD3 T cell stimulation, which results in increased interleukin-2 and interferon gamma(Drug information on interferon gamma). The drug inhibits cell growth by inducing cell cycle arrest and cell death. Given that it is derived from thalidomide, careful attention to birth control must be paid in female patients who are on the medication in order to prevent birth defects. Lenalidomide is used routinely to treat multiple myeloma and thus presents a reasonable choice for extramedullary plasmacytoma that recurs after primary therapy. We would predict that this patient, like most without lymph node involvement, will do well.
We would like to congratulate the authors for a fine case report and review of the literature. The take-home message of this communication is that, while rare, these tumors can occur and may masquerade as anaplastic transitional cell carcinoma. While many patients with anaplastic transitional cell carcinoma may do poorly and should be treated with aggressive surgery, the patients with extramedullary plamacytoma do well with primary radiation. In those tumors that recur, lenalidomide provides salvage therapy.
Financial Disclosure: The authors have no significant financial interest or other relationship with the manufacturers of any products or providers of any service mentioned in this article.