Age / Sex : 67 / F

Age/Sex: 67/F

Chief complaint: Posterior neck pain for 4 month

malignant compression fracture due to Metastatic Adenocarcinoma with mucin production, from pancreas

Discussion

Findings:

Plain Radiographic Findings:

Plain Radiography of cervical spine (Lateral view) shows C4 vertebral body compression fracture.

CT Findings:

Transverse images of computed tomography show permeative destruction of C4 vertebra.

MR Images Findings:

T2 Weighted Sagittal Images show C4 vertebral body compression fracture. Vertebral body signal intensity is heterogeneous and high. The signal intensities of anterior and posterior portions of the compressed vertebral body are mild high signal intensity and extend superiorly and inferiorly.

Whole marrow signal intensity of C4 vertebral body is low and anterior paraspinal space and posterior epidural lesions show low signal intensity on the T1 weighted sagittal images.

The signal intensity of C4 vertebral body and surrounding lesions shows heterogeneous enhancement on the contrast enhanced sagittal images.

T2 Weighted transverse images show C4 vertebral body replaced with innumerous small foci of high signal intensity. The pedicles, laminas and apophyses of C4 cervical vertebra change into similar appearance. Surrounding paraspinal space and posterior epidural space also show the high signal intensities of innumerous small fluid collections.

T1 weighted transverse images show diffuse low signal intensity in the C4 vertebral body, pedicle, apophysis and lamina. Adjacent soft tissue changed contiguous low signal intensity too.

Transverse images after contrast enhancement show mild enhancement of the C4 cervical vertebra and surrounding soft tissue lesions

Differential Diagnosis:

Vertebral Osteomyelitis

Diagnosis:  

Malignant Compression Fracture due to

Metastatic Adenocarcinoma with mucin production, from pancreas

Discussion:

Many disease processes including spinal tuberculosis and pyogenic infections have imaging findings similar to those of metastatic disease. Because of the paucity of distinctive physical signs and symptoms and of the nonspecificity of MR imaging findings, neither the clinical presentation nor the radiologic findings are reliable in helping differentiate spinal infections from spinal neoplasms. Sometimes, the diagnosis depends on findings at adequate biopsy or at bacteriologic and histopathologic examination, particularly if the patient has no known primary neoplasm or systemic illness with diffuse marrow signal change.

In this case, this patient had been presented no known primary neoplasm or other evidence of infectious disease. At first visit to our hospital only with posterior neck pain, we suggested impression of vertebral osteomyelitis with MR images because the C4 lesion was multilocular microcystic that was high signal intensity on the T2 weighted images and enhanced mild heterogeneously on contrast enhanced images. We thought that the microcystic lesion represent inflammatory changes with microabscess. With the pathologic evaluation and further imaging studies of PET scan and abdomen CT, the lesion was diagnosed as metastatic adenocarcinoma with mucin production from pancreas.

When normal bone marrow signal is completely lost, it is not always possible to differentiate fractures caused by malignancy or other processes such as osteomyelitis. In patients with a primary diffuse bone marrow abnormality, the presence of other metastases, pedicle involvement, and intact vertebral disks are secondary findings suggestive of fracture due to metastasis. But there are still several overlaps in the MR images of osteomyelitis and metastasis that justify the pathologic evaluation. With the lesson of this mucin producing metastatic tumor we should scrutinize the MR image and the possibilities of metastatic compression fracture must not be overlooked, because the metastatic lesion may be shown like fluid signal intensities similar to infectious inflammatory lesions.

References:

1. Takyma Y, Kawai D, Makino Y, et al. Vertebral Metastasis of Intraductal Papillary Mucinous Tumor of the Pancreas. Pancreas 2006 Aug; 33(2):206-8

2. Ahmadi J, Bajaj A, Destian S, Segall HD, et al. Spinal tuberculosis : atypical observations at MR imaging. Radiology 1993 Nov; 189(2):489-93

3. Jung HS, Jee WH, McCauley TR et al. Discrimination of metastatic from acute osteoporotic compression spinal fractures with MR imaging. Radiographics 2003 Jan-Feb; 23(1):179-87