Solitary Plasmacytoma In Young Age !!!

Solitary plasmacytoma of bone (SPB) is a localised plasma cell neoplasm. The median age of presentation is 50 years, almost 7 to 10 years less than that of multiple myeloma. The occurrence of SPB in younger age is very rare. To the best of our knowledge, less than 5 cases have been reported less than 20 years. The youngest case reported in medical history is that of a 15 year old girl with manifestation in the humerus bone. Here, we report an 18 year old girl with SPB of right clavicle bone.

Case Report
18 year old girl presented with swelling of right clavicle for past 1 year and sustained pathological fracture of the same following trivial injury. She underwent tumour excision of clavicle & reconstruction using fibular graft with clavicle hook plate on (outside) 28/07/2016. Post op HPE with IHC correlation s/o monoclonal plasmacytosis consistent with plasmacytoma (CD 138 and kappa positive).

Her Battery of Investigation
Serum protein electrophoresis – normal
Immunofixation electrophoresis – normal

Bone marrow aspiration – normocellular with 2% plasma cells. Bone marrow biopsy – scant marrow elements with trilineage haemopoiesis.

X ray of skull (AP and lateral view), dorsal and lumbosacral spine(AP and lateral view), pelvis – Normal

MRI right clavicle (before surgery)(outside) – Expansile lytic lesion in lateral half of right clavicle. Overlying cortex thinned out. Thin cortical fractures visualised in the margins of the lesion, as seen in image.

PET CT (post surgery) – post op changes in right clavicle (SUV-3.92) with no evidence of residual lesion or metastasis.

Treatment Plan
Case discussed in TUMOUR BOARD MEETING and planned for adjuvant radiation to tumour bed as
margin status was not clear.

Course of Radiation
Patient was taken up for External Beam Radiation therapy after appropriate immobilization using head and neck cast and CT based planning was done to deliver a dose of 5040 cGy in 28 fractions using 3DCRT (conformal) technique from 25.10.2016 to 07.10.2016. Patient tolerated radiation therapy well.

This picture depicts 95% dose paint area. The Dose Volume Histogram graph depicts right lung mean dose as 569cGy(normal mean dose must be less than 2000cGy)

Follow Up Plan
Patient will be followed up every 3 months with clinical evaluation, serum protein electrophoresis and immunofixation electrophoresis.