Differentiation of Multiple Myeloma and Metastasis: Emphasis on Bone Marrow Invo l vement Pattern of Spine inSagittal MR Images

PURPOSE: To differentiate multiple myeloma and metastasis of the spine. MATERIALS AND METHODS: Retrospectiveanalysis of MR images of the patients with multifocal spinal involvement of multiple myeloma and metastasis wasdone. Analysis was done in viw points of bone marrow involvement pattern(focal, diffuse, and mixed), margin,number, size and uniformity of the focal lesions, involvement of pedicle and posterior element, and epidural andparavertebral mass formation. RESULTS: Multiple myeloma predominantly showed diffuse pattern (11/21, 52.4%) ofmarrow involvement, while metastasis showed mainly focal pattern (18/21, 85.7%). Margin of the focal lesions weredistinct in majority (8/10, 80%) of multiple myeloma and indistinct in majority (16/21, 76.2%) of metastasis. Sizeof the focal lesions were smaller in cases of multiple myeloma than those of metastasis, but number and standarddeviation of the size of the focal lesions did not show significant difference between the two diseases.Involvement of posterior element were more common in multiple myeloma, and epidural mass formation andparavertebral mass formation were more common in metastasis. CONCLUSION: The diffuse pattern of marrow involvementalone suggests multiple myeloma. When a focal or a mixed pattern is found, distinct margin and smaller focallesions are suggestive of multiple myeloma, and indistinct margin and larger focal lesions andepidural/paravertebral mass formation are suggestive of metastasis.

CT Findings of Primary Malignant Pulmonary Mesenchymal Tumors

PURPOSE: To describe the CT findings and charicteristic clinical manifestation of primary malignant pulmonarymesenchymal tumors. MATERIALS AND METHODS: This study involved nine histopathologically proven cases of malignantprimary pulmonary mesenchymal tumors, as follows : MFH(n=2), leiomyosarcoma(n=2), pulmonary blastoma(n=1),neurogenic sarcoma(n=1), rhabdomyosarcoma(n=1), liposarcoma(n=1) and hemangiopericytoma(n=1). Two patients weremale and seven were female; their median age was 45. We retrospectively analyzed tumor size, location,characteristic of the peripheral margin, relationship to airways, and whether there was distal atelectasis orobstructive pneumonitis and lymph node involvement. We also reviewed distant metastasis, tumor growth rate and theinterval between surgery and recurrence, as seen on follow-up CT scans(n=6). RESULTS: Lesions were located at theright upper (n=2), right middle (n=1), right lower (n=1) and left lower lobe (n=2); in three cases, the whole leftlung (left upper + left lower lobe) was involved. CT findings showed that in all cases, the largest diameter ofmasses ranged from 3 to 15 cm; a well-demarcated margin was seen (smooth in eight cases, psiculated in one) andthis was well enhanced(inhomogeneous in six cases, homogeneous in three). In six cases, masses encircled ordisplaced the peritumoral small bronchus, and in five cases, were located in the peripheral lung field. In fourpatients who underwent endobronchoscopy, no endobronchial lesions were present, and in six cases scans initial CTscans showed no lymph-node involvement. In two cases, mass size doubled within one month. On initial diagnosis,distant metastasis was seen in seven cases, and in three, recurrent lesions were detected within postoperative sixmonths. CONCLUSION: If in the differential diagnosis of lung cancer, a mass seen on CT images is well demarcated,large, peripheral, inhomogeneously enhanced, encircles or displaces the peritumoral small bronchus, shows earlydistant metastasis, is high locally invasive, and recurs early with relative sparing of the lymph nodes, thepossibility of primary malignant pulmonary mesenchymal tumor shouldbe considered.

Usefulness of Stereotactic Localization of Nonpalpable Breast Lesions

PURPOSE: To evaluate the usefulness of stereoscopic localization of nonpalpable breast lesions. MATERIALS AND METHODS: The authors retrospectively analyzed 60 cases of stereotactic localization performed for lesions whichwere mammographically visible but not palpable. Each case was reviewed for chief complaint, indication oflocalization on a mammograph, location of the lesion, pathological diagnosis, and complications during and afterthe procedure. RESULTS: Most patients(75%) had no specific complaint. Among the 60 cases, microcalcification,mass and combined lesions were found in 34(57%), 12(20%), and 14 cases(23%), respectively. The most commonlocation of the lesion was the upper outer quadrant(29 cases). A histopathologic report was available in 56 of 60cases. Among 43 benign cases(76.8%), fibrocystic disease was most common(38 cases, 67.9%), while among 13malignant cases, ductal carcinoma was most common(9 cases, 16.1%). In four of 56 cases(7.1%), failure to removethe target lesion was identified. Retrospective analysis suggests that movement of the patient during theprocedure is the most likely cause of failure. There were no major complications. CONCLUSION: Stereotacticlocalization is simple and accurate, and compared with the conventional method, requires less experience on thepart of the practitioner. Movement of the patient during the procedure may be the major cause of failure.

The Analysis of MR Findings of the Postoperative Diskitis

PURPOSE: To evaluate MR findings of postoperative diskitis following operation for intervertebral disk herniation. MATERIALS AND METHODS: Twelve cases with postoperative diskitis following operation for intervertebral disk herniation were included in this study. MR findings of postoperative diskitis were analysed to determine 1) the extent and pattern of alteration of the involved disks, 2) the pattern of destruction of endplates and vertebral bodies, and 3) the pattern of inflammatory extension into the surrounding soft tissue. RESULTS: 1) Disk alteration developed mainly at the middle and posterior portions of the disk, and was characterized by loss of intranuclear cleft at the involved portion of the disk and intranuclear abscess formation 2) Vertebral bodies involved ware symmetrically adjacent to involved disks and in three cases, bone abscesses within the endplates were detected. 3) The extension of inflammation yielded prevertebral or pre-/paravertebral masses (7 cases), epidural abscesses (5 cases), arachnoiditis (6 cases), and inflammatory masses (2 cases) beneath the posterior longitudinal ligament. CONCLUSION: Disk involvement was mainly at the middle and posterior portions of the disks, and there was accompanying intranuclear cleft loss. Symmetric involvement of the vertebral bodies adjacent to the involved disks was noted.