MULTIPLE MYELOMA

PRITHWIRAJ MAITIFINAL YEAR MBBS

R.G.KAR MEDICAL COLLEGE5.3.2014

Introduction

• It is the most common primary malignant bone tumor.

• Age: It is seen primarily in elderly, in people of >40 years.

• Male gender affected more than female.• Bones affected: Flat bones (Pelvis, vertebrae,

skull, ribs).

Pathogenesis

• Multiple myeloma is a B cell lympho-proliferative disorder with plasma cell predominant.

• There is extensive proliferation of marrow cells.

• There is increased osteoclastic activity, resulting in osteoporosis and discrete lytic lesions.

Clinical features• Multiple myeloma usually follows a chronic course.• Initially the disease is silent, after which the patient presents

with pain on lumber and thoracic spine (back pain), which is progressively increasing in severity.

• Sometimes patient presents with pathological fractures of vertebra and ribs, where acute presentation (pain, redness, swelling etc) is observed.

• Weakness (due to anemia).• Loss of weight.• Local bone tenderness.• Neurological symptoms (from compression of spinal cord/

nerve root) may also be seen.

Other associated features

• Hypercalcemia (due to osteoclastic activity):Thirst,Polyuria,Abdominal pain.• Acute/ chronic renal failure.• Chronic nephritis.• Recurrent infection.

Pathology

• Soft and crumbly in consistency.• Dark red in colour.• Usually located in medulla.• Cortex overlying the tumor is thin and broken.

Microscopy

• Closely packed round cells.• Eccentric nucleus and nucleolus.• Chromatin: “Spokes of wheel” appearance.

Radiology

• Multiple punched out lesion in skull and other bones.

• Pathological wedge collapse in vertebrae (Pedicle sign).

• Erosion of borders of ribs.

Relevant investigations

• Blood:Severe anemia,Very high ESR,High total serum protein,High serum calcium level,Reversal of Albumin: Globulin ratio (normal

1.7:1),Normal Alkaline Phosphatase level. (MCQ)

• Urine: Bence-Jones proteinuria (Ig light chain).• Serum electrophoresis: M band. (γ-globulin).• Sternal puncture: Myeloma cell.

Other investigations

• Bone biopsy (CT guided: from iliac crest).• Bone scan.• Open biopsy.

TREATMENT

GENERAL MEASURES• Control of pain.• Supportive treatment: Fluid-electrolyte

balance.• Limb fracture: Plaster/ splint/ surgery.• Vertebral fracture: Bracing/ surgery.

RADIOTHERAPY• It is applied only in cases of solitary

plasmacytoma.

CHEMOTHERAPY• Melphalan is the drug of choice (MCQ).• Melphalan is an alkylating agent. It sticks to one

of the cancer cell's DNA strands and stops replication.

• It is often used concurrently with Vincristine/ Prednisolone/ Cyclophosphamide.

• 6-12 cycles of chemotherapy are given; the duration between two cycles being 3-4 weeks.

Prognosis

• Multiple myeloma is a widespread disease and fatal.

• Death occurs in the majority of patients within 3 years and in all patients within 5 years.

Complications of Multiple myeloma

• Pathological fractures.• Spinal cord compression and neurological

complications.• Anemia/ leucopenia/ thrombocytopenia.• Severe infections.• Renal failure.• Amyloidosis.