King Edward Memorial Hospital - Departments: Radiology

Radiology

Case of the Month

Case No. :	04
Month :	April
Year :	1999
Contributor :	Dr. Krantikumar Rathod

Other Cases

Clinical Features | Presenting Radiograph | Radiographic Findings | Differential Diagnosis | Discussion

Clinical Profile
Presenting Radiograph
Radiographic Findings
Differential Diagnosis
Case Discussion

Clinical Features :

A 55 year old man presented with painful swelling of right arm following trivial trauma.

He had had generalised bone pain since 2 months.

Presenting Radiograph :

Fig.1

Radiographic Findings :

The frontal radiograph of the right shoulder with humerus shows a transverse fracture of shaft of humerus. In addition, multiple well defined osteolytic lesions are seen in the shaft of the humerus. A skeletal survey was performed

Fig.2
Fig.3	Fig.4
Fig.5	Fig.6

Differential Diagnosis :

Hyperparathyroidism : (HPT)
Generalised osteopenia and multiple brown tumor in HPT can be considered in such a patient. However, these bony changes are usually accompanied by subperiosteal bone resorption, the hallmark of HPT which is more frequently encountered in phalanges of the hands particularly the radial aspect of middle phalanges.
Osteolytic Metastatses :
The lesion of metastases are less discrete, less uniform in size, and often have a moth eaten appearance.
Eosinophillic Granuloma :
This lesion may be associated with single or multiple sharply demarcated radiolucent map like defect which may have punched out appearance of multiple myeloma. However this condition occurs in young age group (below the age of 20) and unassociated with the diffuse osteoporosis4.
Ewing's Tumour, Primary Reticulum Cell Sarcoma, and Lymphoma :
Most of the tumours occur in younger age group and the bone lesions are associated with periosteal reaction.
Cystic Angiomatosis :
This rare condition may produce multiple cyst like lesions in the skull and the remainder of the skeleton. The individual lesions are not punched out and are usually surrounded by a peripheral ring of bone.
Disseminated Bone Tuberculosis :
( cystic type) A rare condition that occurs mainly in children and young adults, this is invariably the result of a hematogenous spread from a distant focus. The multiple lytic foci that appear in the skull and other bones are vaguely defined and do not have the punched out appearance..
Primary Amyloidosis :
This rare entity which may occur independent of multiple myeloma, features osteoporosis of the skeleton with compression deformities of multiple vertebrae and the presence of multiple circumscribed lytic areas. Theelytic foci tend to be bunched together and are seen mainly at the ends of the long bones, particularly of the shoulder and the hip region.

Radiographic bone survey done showed typical features consistent with multiple myeloma.

Frontal radiograph of right shoulder (Fig 1) reveals numerous small and large "punched out " lytic lesions in medulla and cortex of humerus with endosteal scalloping along with pathological fracture and deformity of proximal humerus.

The radiograph of the opposite humerus(Fig 2) shows similar - more prominent changes without a fracture

Frontal radiograph of pelvis with hips (Fig 3) shows diffuse osteopenia and scattered areas of osteolysis.

Lateral radiograph of skull (Fig 4) shows scattered discrete lytic lesions with no marginal zone of sclerosis.

Frontal radiograph of chest (Fig 5) reveals similar lesions in the clavicles with diffuse osteopenia of the ribs.

Frontal radiograph of right femur (Fig 6) reveals widespread punched out lytic lesions in the shaft of the femur.

Blood investigation showed raised serum myeloma protein 7.5 gm/dl, serum B2 microglobulin 5.6 mg/L, IgG level 790 mg/dl. Bone marrow aspiration showed plasma cell count of more than 40%. Thus a diagnosis of multiple myeloma confirmed

Case Discussion :

Plasma cells are derived from B lymphocytes and represents functional unit of the immune system. They are found in the reticulo endothelial rgans such as the lymph node, spleen, bone marrow and the submucosa of the gastro-intestinal tract and are responsible for antibody synthesis.

Multiple myeloma is characterized by diffuse plasma cell infiltration of bone marrow. It is the most common primary malignant neoplasm of bone. It originates usually in the haemopoetic element of the bone marrow (i.e. red marrow) - hence affects predominantly the axial skeletons and occasionally in extra skeletal sites.

Clinical features:

Multiple myeloma occurs commonly between the ages of 40 and 70 years with male predominance. It is rare below the age of 30 years. Most commonly, patient presents with bone pain particularly a back and chest additionally, fever, weight loss, bleeding and neurological signs may be seen. Physical signs includes, fever, pallor, purpura, hepatosplenomegaly, bone tenderness, generalised lymphadenopathy. Extramedullary tumefaction frequently in nasopharynx, nasal fossa and soft palate with co existent amyloidosis may occasionally be seen.
Laboratory investigations reveal moderate to severe anaemia, elevated ESR, a normal or slightly elevated lucocyte count, positive Coomb's test, thrombocytopenia, hypercalcemia and hyperuricemia may be observed. Renal insufficiency may lead to an elevated serum creatinine concentration.
Most patients demonstrate an increase in total serum protein, usually due to an increase in globulin fraction as shown in serum electrophoresis.
Urinary electrophoresis may show Bence-Jones proteinuria.
Bone marrow aspiration and bone biopsy are important in establishing the definitive diagnosis. The presence of more than 10% of plasma cells in a given specimen is suggestive and more than 40% is indicative of plasma cell myeloma on marrow analysis.
The measure cause of death in patient with myeloma are infection and renal failure.

Pathogenesis:

The cause of plasma cell proliferation in plasma cell myeloma is unknown. The theories of viral etiology or related to chronic myeloproliferative disorder and genetic predisposition as a causative agent has been suggested.
Plasma cell infiltration can produce an osteoclastic stimulating factor that may be responsible for the osteolytic lesion, that are characteristic of myeloma. This factor is also leads to inhibition of osteoblasts, although some investigator believe that another humoral factor, an osteoblast inhibiting factor, accounts for the poor or absent osteoblastic response that is characteristic of myeloma.
Plasma cell infiltration at first in axial skeleton, at which it leads to destruction of marrow. The body responds to this decrease in active marrow by reconversion of yellow to red marrow in appendicular skeleton predominantly proximal ends of femori and humeri. Eventually plasma cells invade peripheral skeletal sites as well. With increased cellular proliferation, extensive bone destruction, pathological fractures and hypercalcemia become evident.
Multiple myeloma displays a wide range of radiological manifestations that depend, to great extent, on the duration of the disease. Although certain roentgen pattern in specific bones may strongly suggest a diagnosis, particularly when patient is over age of 40. There are however, no reliable findings that can be regarded as a pathognomic of the disease. Multiple myeloma should be considered in the differential diagnosis of any patient over 40 who complains of vague aches and pains and shows unusually severe osteoporosis, the latter may be the only radiographic abnormality in up to a third of patients.
In myelomatosis of the skull, multiple foci can often be found in the mandible as well, whereas this is relatively rare occurrence in metastatic carcinoma. Multiple myeloma in the spine features diffuse osteoporosis as well as lytic foci in the vertebral bodies. Myelomatous infiltration may extend into the disc and invade contiguous vertebrae. Metastatic carcinoma, on the other hand, usually does not cross the disc space and there is less tendency for multiple vertebral involvement. In multiple myeloma ,the pedicle of the vertebrae are involved later in the disease in contrast to metastatic disease which affects the pedicle frequently and early. Pathologic fractures and formation of a soft tissue masses (para spinal and extrapleural) are frequently associated with myelomatous lesion of the spine and ribs than metastatic carcinoma.