Our team Dr. Clarke & Dr. Vargas Shinoj & Arvind Jacob & Muneeza Chloe, Lauren & Njiye
History 57 yo women presented with 3 day h/o -left sided chest pain. diffuse, pressure like, pleuritic, radiating to the back, 4/10 on pain scale and non exertional. -no shortness of breath PMH: unremarkable
Imaging Chest X ray: “ Mass noted in the left lateral upper lobe of the lung eroding into the fifth rib ”. CT angiogram: “ Pleural-based mass in the posterior segment of the left upper lobe with bony erosions through the posterior fifth rib ”.
D/D Arising from the pleura - localized malignant mesothelioma, solitary fibrous pleural tumour. Arising from lung parenchyma - adenocarcinoma Arising from the bone - Fibrous dysplasia, Paget’s disease - Chondrosarcoma, Osteosarcoma - Multiple myeloma, Plasmacytoma
Work up Plan was to get a tissue diagnosis, possibly a bronchoscopy. Pulmonary service were consulted Pulmonary recs - most likely adenocarcinoma. - recommended IR guided biopsy as the mass is not accessible to bronch due to its location.
Pathology report IR guided biopsy was performed. The biopsy result came back as “ PLASMACYTOMA ”
Plasmacytoma Plasmacytoma is a discrete, solitary mass of neoplastic monoclonal plasma cells. Types Solitary bone plasmacytoma (SBP) Soft tissue or non-osseous extramedullary plasmacytoma (EMP)
Pathophysiology SBP : Arise from plasma cells of bone marrow EMP: From plasma cells of mucosal surfaces SBP ~ 5% of plasma cell disorders EMP ~ 3% of plasma cell disorders The median age of patients with SBP or EMP is 55 years. This median age is 10 years younger than patients with multiple myeloma.
Presentation The most common symptom - pain at the site of the skeletal lesion due to bone destruction by the infiltrating plasma cell tumor. Vertebral involvement may also have evidence of nerve root or spinal cord compression.
Labs Serum electrophoresis reveals a monoclonal protein in the serum or urine in 24-72% of patients, although levels are lower than in multiple myeloma. Uninvolved immunoglobulin levels are usually within the reference range. Peripheral blood cell count, renal function, and calcium are within the reference range.
Imaging and histology Chest X ray: A lytic appearance with clear margins and a narrow zone of transition to healthy surrounding bone MRI: abnormal signal intensity (low on T1- weighted imaging and high on T2-weighted) Histology: reveals infiltration of the bone by monoclonal plasma cells.
SBP- Diagnostic criteria 1. Single area of bone destruction by clonal plasma cells 2. Bone marrow plasma cell infiltration not exceeding 5% of all nucleated cells. 3. Absence of osteolytic bone lesions or other tissue involvement (no e/o myeloma). 4. Absence of anaemia, hypercalcemia, or renal impairment attributable to myeloma. 5. Low, if present, concentrations of serum or urine monoclonal protein. 6. Preserved levels of uninvolved immunoglobulins
Treatment Local radiotherapy is the treatment of choice. Local control achieved in 88-100% of patients. All patients have major symptom relief. Local tumor recurrence rate of apprx 10%. Monoclonal protein is markedly reduced after radiotherapy in the majority of patients, but protein disappearance is observed in only 20- 50% of patients.
Role of surgery & chemotherapy Surgery is contraindicated in the absence of structural instability or neurologic compromise Chemotherapy may be considered for patients not responding to radiation therapy. Regimens useful in multiple myeloma can be considered. No role exists for adjuvant chemotherapy in solitary bone plasmacytoma.
Prognosis Solitary bone plasmacytoma (SBP) progresses to multiple myeloma at a rate of 65-84% at 10 years and 65-100% at 15 years. The median onset of conversion to multiple myeloma is 2-5 years with a 10-year disease-free survival rate of 15-46%. The overall median survival time is 10 years.
Treatment failure 3 patterns of treatment failure described : 1> development of multiple myeloma (54%) 2> local recurrence (11%), and 3> development of new bone lesions in the absence of multiple myeloma (2%).
Prognostic factors for conversion Lesion size of at least 5 cm High M protein levels Persistence of M protein after treatment Elevated B2 microglobulin Spine lesions In a study by Wilder et al, 10-year myeloma- free survival was 91% versus 29% in patients whose M-protein did or did not resolve at 1 year following radiation therapy.
Role of b2 microglobulin Southwest oncology group study Beta 2 microglobulin is used as a prognostic marker in multiple myeloma. 322 patients with pretreatment serum b2m values of less than 6 mcg/mL, median survival was 36 months. 225 patients with a b2m level of greater than or equal to 6 mcg/mL, median survival of 23 months (P less than.0001).
Back to my patient Skeletal survey: no lytic lesions. Serum immunofixation: normal Urine immunofixation: small monoclonal spike of IgG kappa light chains Normal renal function. No anaemia, hypercalcemia.
Scheduled for bone marrow biopsy next week. If bone marrow shows less than 5% plasma cells – Plasmacytoma. Radiation therapy is the next step. Finally, close follow up to look for progression to multiple myeloma…………at my GMC !!!