Multiple Myeloma

Multiple Myeloma is characterized by the presence of neoplastic plasma cells, which replaces bone and marrow spaces.

In this scenario there is the formation of abnormal protein leads to immune deficiency and complications that hasten fatal termination.

Other names are:

• myelomatosis
• multiple myelomatoses
• solitary myeloma
• plasmacytoma
• monoclonal gammopathy

Etiology of MM

Genetic cause

Chronic Inflammation

Environmental cause

Radiation

Infection

Monoclonal gammopathy of undetermined significance (MGUS) might progress to full-blown multiple myeloma.

Age predisposition: 40-70 years

Male > Female

Clinical Features of MM

30 % of asymptomatic people were detected accidentally

Pain

Anaemia

Infections

Weakness

Hypercalcemia

Pathological fractures

Spinal cord compression

Renal failure

• Tubular blockage by protein cast (Myeloma Kidney)

Malaise

Fever

Sluggish activities

Paresthesia

Sensory loss

Rheumatic-like pain in back and loins

Fatal termination: Extensive marrow replacement, severe anemia, thrombocytopenia, and hemorrhages

Radiological Features

Generalized osteoporosis

Biconcave vertebral bodies

Vertebral collapse

Osteolytic defects rarely observed in vertebral bodies: As the bone collapse

Rarefraction of vertebral progress:- Complete dissolution may extend throughout the vertebrae

Disappearing Vertebrae

MRI: To detect spinal lesions

POEMS: Polyneuropathy + Organomegaly + Endocrinopathy + M-proteins +Skin changes ( Skin thickening, Hypertrichosis, Hyperpigmentation)

POEMS: Osteosclerotic Myeloma

Laboratory Diagnosis

3 Components:

1. Presence of paraprotein in serum or urine (serum b2 microglobulin, urine Bence-jones protein, hyperglobinemia, and M-band detected on electrophoresis
2. Infiltration of malignant plasma cells in the bone marrow is assessed by bone marrow aspirate and biopsy. A sample of marrow can be taken from the sternum and illum
3. The bone lesion is screened for by skeletal survey and MRI

Anemia (Normocytic, Normochromic), Lymphocytosis

Rouleaux formation

Hypercalcemia (Renal Involvement)

Decrease in ALP despite extensive bone destruction

Staging system of Multiple Myeloma

There are 2 staging system

1. Salmon-Durie System (1975)
2. International Staging System (2005)

International Staging System

Stage	The concentration of components in serum	Median survival rate (%)
I	β2 microglobulin ≤ 3.5 mg/dl and albumin ≥ 3.5gm/dl	62
II	β2 microglobulin < 3.5 mg/dl and albumin < 3.5gm/dl or β2 microglobulin 3.5-5.5 mg/dl	44
III	β2 microglobulin > 5.5 mg/dl	29

Pathology

( > 30 %) increase in plasma cells (mature, immature, pleomorphic, anaplastic)

Nuclear chromatin: ” Spoke wheel/ Clock face pattern”

Treatment

There is no cure for Multiple Myeloma (Invariably fatal)

1. Supportive Medical Therapy
   • Adequate hydration
   • Prophylactic antibiotics
   • Bisphosphonates ( Inhibit proliferation of myeloma cells)
2. Chemotherapy
   • Thalidomide and dexamethasone
   • In relapsed / Refractory cases: Melphalan, Cyclophosphamide, Etoposide, and Cisplatin + Dexamethasone
3. Autologous Stem cell transplantation
4. Radiation therapy
5. Surgical Cases: Intramedullary fixation + Radiotherapy

See also: Musculoskeletal Malignancy: Management

See also: Osteosarcoma

See also: Ewing Sarcoma

See also: Chondrosarcoma