Image Quiz

Pathologic Fracture of the Humerus During Pregnancy (continued)

Answer: Multiple myeloma with a pathologic fracture.


Fig. 1-A
Fig. 1-B		 Fig. 1-A Anteroposterior radiograph of the right arm, demonstrating generalized demineralization of the proximal aspect of the humerus with a pathologic fracture of the surgical neck, an impending fracture in the mid-diaphysis, and a large focal lesion within the lateral epicondyle.
Fig. 1-B Anteroposterior radiograph of the right forearm, demonstrating characteristic punched-out lesions of multiple myeloma within the radius and ulna.

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Magnetic resonance imaging of the abdomen and pelvis showed diffuse changes in the bone marrow of the spine and pelvis that were consistent with replacement by malignant cells. Vertebral compression fractures were evident in the upper lumbar region, and two large focal lesions with associated destruction of the cortex were seen in the left hemipelvis (Figs. 2-A and 2-B). A computed tomography-guided core biopsy of the right humeral lesion demonstrated sheets of plasma cells (Fig. 3). A diagnosis of multiple myeloma was made.


Fig. 2-A
Fig. 2-B
Fig. 3
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Figs. 2-A and 2-B Magnetic resonance images of the pelvis, showing a gravid uterus and myelomatous lesions.
Fig. 2-A Infiltration of the left ilium near the sacroiliac joint.
Fig. 2-B Infiltration of the left iliac wing, with a soft-tissue component posteriorly.
Fig. 3 Photomicrograph of a specimen taken from the humeral fracture site, demonstrating sheet-like masses of plasma cells that have replaced the normal marrow elements (hematoxylin and eosin, ×40).

The patient was admitted to the hospital, and a multidisciplinary team consisting of members of the departments of orthopaedics, obstetrics, and oncology was established to supervise her care. The fracture of the surgical neck of the right humerus was stabilized with a brace, and Decadron (dexamethasone) was given as an induction agent to decrease the tumor mass. The secondary metabolic abnormalities were treated with the administration of blood transfusions for anemia; with hydration, diuresis, and the administration of pamidronate for hypercalcemia; and with the administration of allopurinol for hyperuricemia. At the recommendation of the orthopaedic surgeons, the decision was made to deliver the child by cesarean section to avoid subjecting the diseased lumbosacral spine and pelvis to the stress that would be associated with a vaginal birth.

Discussion

Multiple myeloma is the most common primary malignant tumor of bone, with approximately 15,000 new cases in the United States each year. Lytic bone lesions are produced throughout the skeleton as the result of a monoclonal proliferation of plasma cells that invade the medullary space and activate osteoclasts. Bone pain is the most common symptom of myeloma and may herald an impending or pathologic fracture. Other clinical manifestations, such as hypercalcemia, renal failure, immune deficiency, and anemia, occur secondary to the production and accumulation of monoclonal proteins, including immunoglobulins and light-chain components.

The mean age at the time of diagnosis is sixty-six years, with most cases diagnosed between the sixth and eighth decades of life. The presentation of multiple myeloma during a woman's childbearing years is exceedingly unusual. To our knowledge, there have been fewer than a dozen reports of multiple myeloma in pregnant patients and only three reports of multiple myeloma being diagnosed during pregnancy. To our knowledge, this is the first reported case of myeloma presenting as a pathologic fracture.

Women are becoming pregnant at older ages. Because cancer is the leading cause of death in women who are forty to fifty-nine years of age, orthopaedists can expect to see an increasing number of pregnant women with osseous lesions. Skeletal disease should be managed under conditions that minimize fetal exposure to ionizing radiation and harmful drugs. The dangers of labor and vaginal delivery may be increased when the patient has lytic lesions of the lumbosacral spine and the pelvis.

Reference

1. Forthman CL, Ponce BA, Mankin HJ. Multiple myeloma with a pathologic fracture during pregnancy. A case report. J Bone Joint Surg Am. 2004;86:1284-8.