Extramedullary Plasmacytoma Mimicking Pancreatic Cancer: An Unusual Presentation

Abstract

Multiple myeloma is a plasma cell tumor that homes to and expands in the bone marrow and that, despite the new available drugs, remains incurable. Extramedullary plasmacytoma is a not frequent manifestation during the natural history of multiple myeloma and is frequently associated with plasma cell bone marrow infiltration. The most common locations for an EMP include the gastrointestinal tract, pleura, testis, skin, peritoneum, liver, endocrine glands, and lymph nodes. Primary involvement of the gallbladder fossa is exceedingly rare. In this report, we describe a patient with multiple myeloma who achieved a clinical and serological remission after autologous transplant but progressed rapidly at extramedullary site mimicking a second cancer (i.e., pancreatic or biliary cancer). In this case, the extramedullary localization was refractory to standard therapy, differently from bone marrow localization, but responded to lymphoma-like therapy. In this patient (i) the particular site of developing plasmacytoma is the gallbladder fossa, (ii) the timing of onset of this neoplasm is immediately after autologous transplant, and (iii) its disjunction from primary myeloma is that it appears in clinical and serological remission phase which may be confounding during the diagnostic approach simulating a different tumor (solid tumor).

A Case of Concurrent Gastric and Pancreatic Plasmacytomas in a Patient With Multiple Myeloma: An Extremely Rare Entity

“…Most patients presented with features of obstructive jaundice, and one case was diagnosed during autopsy. 4 , 18 - 30 …”

Secondary Extramedullary Myeloma of the Gallbladder: A Case Report

“…Gallbladder involvement in EMM, however, is extremely rare, with only 8 cases found in the English medical literature. 4 - 11 …”

Obstructive jaundice caused by pancreatic plasmacytoma secondary to multiple myeloma: A case report and literature review

“…As shown in Table 1 . 4,16,18,27,28,34 This finding suggests that secondary pancreatic plasmacytoma is an indication for uncontrolled myeloma progression but may be the first or only manifestation of myeloma recurrence.…”

“…5 However, the management of secondary plasmacytoma requires systemic chemotherapeutics, which can be administered in combination with radiotherapy. 2,34 Currently, there is no consensus over chemotherapy regimen options or their efficacy in this population. In our patient the pancreatic plasmacytoma dis- reported in the available literature.…”

“…The most common manifestations include jaundice and abdominal pain, which are often related to biliary obstruction caused by the mass in the pancreatic head. Serum level of cancer antigen 19-9 is normal in most patientswhile it is significantly elevated in some of them,4,18,34 which complicates the differential diagnosis of pancreatic cancer.…”