DIAGNOSTIC CHALLENGE: COEXISTING MULTIPLE MYELOMA AND EXTRAMEDULLARY PLASMACYTOMA WITH RENAL AND HEPATIC INVOLVEMENT

Both plasmacytoma and multiple myeloma (MM) are plasma cell dyscrasias, though their concurrence, especially with the unusual extramedullary presentation of plasmacytoma, is exceedingly rare. Distinguishing between them is crucial for management, especially in the presence of atypical findings that complicate the diagnosis.

Herein, we describe a rare instance of synchronous plasmacytoma and multiple myeloma (MM) in a 65-year-old woman. The patient did not have any preceding symptoms or complaints and was living her life with no limitations until the day she fell and fractured. Preoperative examinations by a traumatologist demonstrated anemia, increased rates of nitrogen metabolism, and a mass in the right kidney. The above findings led to the cancellation of the surgery and encouraged our team to go into more detail. Computed tomography (CT) scans showed a renal mass and liver lesions. During the diagnostic procedure, special attention was given to the acutely high level of total protein in the blood plasma, for which investigations were directed in another avenue. Electrophoresis of blood and urine and bone marrow biopsy established the diagnosis of MM, although the typical CRAB criteria were absent. Laboratory findings present conflicting evidence, with some results suggesting MM and others suggesting plasmacytoma. Clarification was especially important since the renal mass was initially thought to be renal cell carcinoma and needed to be distinguished carefully. Due to the uncommon coexistence of these diseases, we examined both literature and clinical cases in order to investigate their simultaneous occurrence.

This case illustrates the diagnostic dilemma of simultaneous MM and plasmacytoma, highlighting the importance of thorough assessment, including histology and modern imaging. The fact that there are hepatic metastases also points to the aggressive nature of this unusual disease presentation.