Patient 01: 51 – year – old woman, with metastatic carcinoma of the breast.
Patient 02: 43 – year – old woman, with metastatic carcinoma of the breast.
Patient 03: 47 – year – old woman, with metastatic carcinoma of the breast.
Patient 04: 63 – year – old man, with metastatic carcinoma of the prostate.
Patient 05: 48 – year – old man, with metastatic carcinoma of the lung.
Figure 01 (patient 01): Lateral skull film demonstrates multiple lytic lesions in the calvaria, in a patient with carcinoma of the breast.
Figure 02 (patient 02): Axial computed tomography ( CT) scan shows sclerotic lesion in the left temporal bone and left great wing of the sphenoid, in a patient with carcinoma of the breast.
Figure 03 (patient 03): Lateral radiograph reveals multiple sclerotic bone metastases in the skull vault, in a patient with carcinoma of the breast.
Figure 04 (patient 03): Axial postcontrast T1 weighted SE scan the normal high signal intensity of fatty marrow in the diploic space of the cranial vault on T1 weighted images has been partially replaced by multiple hypointensity round lesions in the calvaria.
Figure 05 (patient 03): Axial T2 weighted scan Multiple hypointensity round lesions in the calvarium.
Figure 06 (patient 04): CT scan demonstrates right occipital mixed osteolytic-sclerotic lesion, in a patient with carcinoma of the prostate; there is also bilateral sclerosis and thickened involving the temporal and sphenoid bones.
Figure 07 (patient 05): CT scan shows areas of bone destruction involving the right occipital and the right sphenoid bones, in a patient with carcinoma of the lung.
Figure 08 (patient 05): CT scan reveals multiple areas of bone destruction involving the right calvarium, most prominent in frontal and parietal regions.
|Diagnosis: Calvaria metastases.|
Bone metastases are often multiple at the time of diagnosis. In adults, the lesions generally occur in the axial skeleton and other sites with residual red marrow, although the lesions may be found anywhere in the skeletal system. Common sites for metastases are the vertebrae, pelvis, proximal parts of the femur, ribs, proximal part of the humerus, and calvaria. More than 90% of metastases are found in this distribution.
Metastases from carcinoma are by far the most common malignant tumors involving the skeleton. Metastases to the calvarium in the adult age group may occur from a wide variety of tumors, with the most common sites of primary tumors being from carcinoma of the breast, the prostate, the lung, the thyroid and the kidney.
Metastases from certain primary sites (eg, breast, renal cell or thyroid carcinomas) are almost always osteolytic, whereas those from other sites (eg, prostatic carcinoma) are predominantly sclerotic. Other malignancies associated with a mixed lytic and blastic appearance include breast carcinoma, colonic carcinoma, melanoma, bladder carcinoma, and soft-tissue sarcoma.
Swelling and local pain are the usual presenting symptoms. They produce symptoms by expansion of the skull or compression of the adjacent brain or venous sinuses. Associated neurological deficit suggests intracranial extension.
Imaging has an important role in the detection, diagnosis, prognostication, treatment planning, and follow-up monitoring of bone metastases. In patients with proven nonskeletal tumors, imaging is useful for screening the skeleton to assess metastatic disease and, if it is present, to determine its extent.
Radiography is relatively insensitive in detecting bone metastases, especially subtle lesions. Metastases to bone become apparent on radiographs only after there is loss of more than 50% of the bone mineral content at the site of disease. Radiologically osteolytic metastases appear as multiple poorly marginated lytic lesions and blastic ones appear as focal areas of increased density. Occasionally in some cases (eg. breast cancer), the skull metastases may appear as mixed lucent and sclerotic areas. Plain x rays are positive in 60% of cases and computed tomography (CT) in 85%.
CT scan has mostly replaced plain x-rays. It provides accurate information regarding the involvement of the skull bones as well as the intracranial and extracranial soft tissues. Contrast studies assess the vascularity and the involvement of dural venous sinuses. Subtle meningeal involvement may be missed. Enhanced magnetic resonance Imaging (MRI) demonstrates this meningeal involvement much better than CT does.
MRI provides better delineation of soft tissue involvement. As compact cortical bone lacks in unbound protons, the inner and outer tables appear as a signal void. The diploe has abundant fat and hence images well. Lytic lesions are seen as focal or diffuse areas of hypointensity on T1-weighted images and as areas of intermediate or high signal intensity on T2-weighted images. Blastic lesions usually shows areas of hypointensity on T1 and T2 sequences. Tumor deposits typically appear hyperintense against a dark background of suppressed signal intensity within fat on STIR images.
99m Tc bone scintiscan findings are nonspecific in determining the cause of increased uptake. Bone scintiscans have the disadvantages of poor spatial and contrast resolution. In many patients, further imaging is required to characterize regions of disseminated abnormality. Bone scintiscanning continues to be used as the initial screening investigation because of its relatively low cost, wide availability, and usefulness in imaging the entire skeleton.
FDG-PET scanning depicts early malignant bone-marrow infiltration because of the early increased glucose metabolism in neoplastic cells. FDG-PET scanning are accurate techniques that are currently limited by their high cost.
Biopsy may be needed to histopathological study of the lesion.
Treatment is correlated with that of the primary tumor. Surgery, radiotherapy and chemotherapy are often used in combination as in other bone tumors.
1. Latchaw, RE. MR and CT Imaging of the Head, Neck, and Spine. 2nd ed. Mosby Year Book, Inc. St. Louis, Mo. 1991.
2. Peh, CGW; Muttarak , M. Imaging in Bone metastases. Emedicine. Medscape. http://emedicine.medscape.com/article/387840-overview#a01 May 25, 2011.
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Case Number: 54620796Last Updated: 2011-08-29 The reader is fully responsible for confirming the accuracy of this content.
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