Case of the Week - Patient Summary 13097Peer Reviewed and Certified -
A large lytic lesion at the vertex disrupts both the inner and outer table.
T1 Sag: Large expansile mass lesion which is hypointense to bone marrow extending intracranially from the frontal clavarium.
T1 Cor: Large expansile mass lesion which is hypointense to bone marrow extending intracranially from the frontal clavarium.
T1 Ax +C: Enhancing expansile mass lesion extending intracranially and superficially from the calvarium.
T1 Cor +C: Enhancing expansile mass lesion extending intracranially and superficially from the calvarium.
T2 Ax: Expansile mass which is isointense to bone marrow extending both intracranially and superficially from the calvarium.
• Lytic metastasis
• Hemangioma
• Brown Tumor
• Hemangiopericytoma
• Meningiomatosis
Multiple Myeloma The etiology of multiple myeloma is unknown. It is more common in the elderly and there is a slight increased risk among children and siblings of multiple myeloma patients. There is also an increased incidence amongst petroleum, leather, and cosmetology workers. Additionally, exposure to radiation (greater than 50 rad), hebricides, insecticides, heavy metals, plastics, and asbestos also increases risk.
“Punched-out” lytic lesions are a common finding on plain film. An osteolytic skull lesion is the best diagnostic clue on imaging. The appearance can vary on T1-weighted MRI, ranging from focal hyperintensity in 53% of cases to a focal hypointensity in 25% of cases. Marked lesional enhancement is seen following gadolinium administration. On T2 weighted imaging, an iso- to hyperintense lesion can be seen. Intracranial myeloma, as in this patient, is a rare finding.
References:
Angtuaco EJ, et al. Multiple myeloma: clinical review and diagnostic imaging. Radiology. 2004; 231(1):11-23.
Brant WE, Helms CA. Fundamentals of Diagnostic Radiology. Lippincott, Williams & Wilkins. Philadelphia. 2007
Osborn AG. Diagnostic Neuroradiology. Mosby. St Louis. 1994.
Smith, A, Wisloff, F, Samson, D. Guidelines on the diagnosis and management of multiple myeloma 2005. British Journal of Haematology. 2006; 132:410.
Laboratory findings include elevated ESR, anemia, hypercalcemia and hyperuricemia. Elevated globin levels are present, usually involving IgG, but any of the immunoglobulins may be produced. The plasma cell burden will eventually displace and erode the bony trabeculae and give rise to the musculoskeletal symptoms.
Classically, multiple myeloma will appear as osteolytic lesions. These arise predominantly in the verterbral bodies, ribs, skull, pelvis and femur. However, diffuse skeletal osteopenia may be observed without focal lytic lesions. Pathologic fractures are common.
Both plain films and MDP scintigraphy have a significant false negative problem: Plain film false negative 9-25%; and, MDP false negative 40-60%. - LINK -
However, FDG PET may be useful, with a sensitivity of 85% and specificity of 92% reported. PMID: 15788594
