Group Of Malignant Lesions Research Articles

Benign Spindle Cell Tumor Not Otherwise Specified (NOS) in a Male Breast

Breast spindle cell tumors (BSCTs), although uncommon, constitute a heterogeneous group of benign and malignant lesions, often necessitating different therapeutic approaches. This study describes the case of a 62-year-old man who displayed a gradually growing retroareolar tumor of the left breast. The mass was well circumscribed, unilateral, and grossly nodular. The patient eventually underwent wide local excision of the mass. The lesion was made up of spindle cells arranged in fascicular clusters, separated by bands of collagen. No mitotic figures were observed. Immunohistochemically, the mass expressed strong and diffuse cytoplasmic staining for vimentin, CD34, CD10, and bcl-2, whereas it was negative for cytokeratins, smooth muscle actin, desmin, S-100 protein, p53, Ki-67, estrogen and progesterone receptors. Diverse histological results and immunohistochemical features established the diagnosis of benign BSCT, not otherwise specified. The patient remains disease-free 12 months after lumpectomy. This case report adds to the spectrum of the benign BSCTs and delineates the nature of different types of these lesions, in order to carefully select optimal therapeutic regimes.

Nuclear to non-nuclear Pmel17/gp100 expression (HMB45 staining) as a discriminator between benign and malignant melanocytic lesions

HMB45 is a mouse monoclonal antibody raised against Pmel17/gp100, a melanoma-specific marker, which is routinely used in the diagnosis of primary cutaneous malignant melanoma. The standard expression pattern for a positive HMB45 staining result on immunohistochemistry is based upon the results of chromogenic-based methods. We re-evaluated the patterns of HMB45 staining across the 480-core ‘SPORE melanoma progression array’ containing lesions representing the spectrum of melanocytic lesions ranging from thin nevus to visceral metastasis using the fluorescence-based staining technique and automated quantitative analysis (AQUA) of the obtained digital images. The methods validated the expected cytoplasmic HMB45 staining pattern in 70/108 malignant lesions and in the epithelial components of nevus specimens. However, the fluorescence-based approach revealed a nuclear gp100 localization present in the dermal component of all nevi that was not seen before. This nuclear localization could not be observed on routine chromogenic stains, because the standard hematoxylin nuclear counterstain overwhelms the weak nuclear HMB45 stain. The thin (0.450±0.253) and thick (0.513±0.227) nevi had strongly positive mean ln(nuclear/non-nuclear AQUA score ratios), which are significantly higher than those from the group of malignant lesions (P<0.0001). This finding was reproduced on a smaller but independent progression array composed of nevi and melanomas from the Yale Pathology archives (P<0.01). The odds ratio associated with a sample being a nevus was 2.24 (95% CI: 1.87–2.69, P<0.0001) for each 0.1 unit increase of the ln(nuclear/non-nuclear AQUA score ratio) to yield an ROC curve with 0.93 units of area and a simultaneously maximized sensitivity of 0.92 and specificity of 0.80 for distinguishing benign nevi from malignant melanomas. On the basis of this preliminary study, we propose that the ratio of nuclear to non-nuclear HMB45 staining may be useful for diagnostic challenges in melanocytic lesions.

The role of Doppler Perfusion Index as screening test in the characterization of focal liver lesions

Purpose Doppler Perfusion Index (DPI) has been used in the detection of overt liver metastatic disease. In the present prospective study we evaluated the use of DPI in the differential diagnosis of liver tumours. Materials and methods We have included in our study 76 patients with focal hepatic lesion and 39 subjects as control group. All patients were evaluated by Color Doppler Ultrasound, and/or Spiral Computerised Tomography, Magnetic Resonance Imaging and biopsy. The radiologist performed DPI measurements was blind from the final diagnosis of the other methods. Results DPI measurements in the control group ranged from 0.07 to 0.22 (mean value 0.14), in 42 cases with benign lesions (group A) ranged from 0.05 to 0.53 (mean 0.15) and in 34 cases with malignant lesions (group B) ranged from 0.39 to 0.75 (mean 0.53). There was a statistically significant difference in DPI measurements between the control group and group B. Conclusions Our results suggest that the DPI may differentiate malignant from benign focal hepatic lesions and therefore can be used as a screening test in the routine clinical practice.

Experimental and clinical observations of 99mTc-MIBI uptake correlate with P-glycoprotein expression in lung cancer

99mTc-methoxyisobutylisonitrile (99mTc-MIBI) has been used as a tumour positive scintigraphic agent for diagnostic purposes. However, the pharmaceutical kinetics and accumulation patterns of 99mTc-MIBI in tumour tissues (both in vitro and in vivo) remained poorly understood. Using human embryonic lung fibroblasts (HLFs) as a control, we investigated the kinetics of 99mTc-MIBI accumulation in four human cancer cell lines. We found that, among the tested groups, the uptake rate (UR) of 99mTc-MIBI in normal lung fibroblast cells was the lowest at 90 min after injection, while the UR of four groups of carcinoma cells increased significantly. A significant change of the UR value was observed under cellular depolarization and hyperpolarization. Interestingly, we found that malonic acid, a respiratory chain inhibitor, could inhibit UR rates by 27% from the lowered level in hyper-potassium condition. We also used a semi-quantitative method to analyse 99mTc-MIBI imaging results from 93 clinical cases of pathologically or cytologically confirmed lung cancer lesions. We found that the UR value of a lung benign lesion group was significantly lower than that of a malignant lesion group. We conclude that the sensitivity, specificity and accuracy of 99mTc-MIBI imaging for the lung occupied cancer lesions were 89.83%, 79.41% and 86.02%, respectively. We also investigated the relationship between P-gp expression and MIBI uptake in 25 clinical cases. These observations demonstrate a close relationship between the state of 99mTc-MIBI accumulation and the metabolic level of tumour cells and the P-gp expression. Our data suggest that 99mTcc-MIBI semi-quantitative imaging is useful for the qualitative diagnosis of lung-occupied cancer lesions and may be a potential predictor of the P-gp expression in the clinic.

Benign versus Malignant Breast Masses: Optical Differentiation with US-guided Optical Imaging Reconstruction

To investigate prospectively the feasibility of using optical tomography with ultrasonographic (US) localization to differentiate malignant from benign breast masses and to compare optical tomography with color Doppler US. The study was approved by the local internal review board committee and by the Human Subjects Research Review Board of Army Medical Research and Materiel Command. Signed informed consent was obtained, and the study was HIPAA compliant. Between May 2003 and March 2004, 65 consecutive women (mean age, 51 years; age range, 24-80 years) with 81 breast lesions underwent US-guided biopsy and were scanned with a combined imager. The hand-held probe, which consisted of a centrally located US transducer surrounded by near-infrared sensors, was used to simultaneously acquire coregistered US images and optical data. The lesion location obtained at US was used to guide optical imaging reconstruction. Light absorption was measured at two wavelengths. From these measurements, tumor angiogenesis was assessed on the basis of calculated total hemoglobin concentration. A Student t distribution was used to calculate the statistical significance of mean maximum and mean average hemoglobin concentrations obtained in malignant and benign lesion groups, and P < .001 was considered to indicate a statistically significant difference. Biopsy results revealed eight early stage invasive carcinomas (malignant group) and 73 benign lesions (benign group). The mean maximum and mean average hemoglobin concentrations in the malignant group were 122 micromol/L +/- 26.8 (+/- standard deviation) and 88 micromol/L +/- 24.5, respectively. The mean maximum and mean average hemoglobin concentrations in the benign group were 55 micromol/L +/- 24.8 and 38 micromol/L +/- 17.4, respectively. Both the maximum and average total hemoglobin concentrations were significantly higher in the malignant group compared with the benign group (P < .001). When a maximum hemoglobin concentration of 95 micromol/L was used as the threshold value, the sensitivity, specificity, positive predictive value, and negative predictive value of optical tomography were 100%, 96%, 73%, and 100%, respectively, and the sensitivity, specificity, positive predictive value, and negative predictive value of color Doppler US were 63%, 69%, 19%, and 94%, respectively. Findings indicate that optical tomography with US localization is feasible for differentiating benign and early stage malignant breast lesions.

Treatment of an Oral Malignant Lymphoma by Combined Surgery and Chemotherapy-Case Report

Lymphoma is the third most common group of malignant lesions of the oral cavity and maxillofacial region. Most of the non-Hodgkin's lymphomas (NHL) of the head and neck region are predominantly of B-cell lineage. In general, localized extranodal lymphomas are most commonly treated by radiotherapy or in combination with either surgery or chemotherapy. In this report, we presented a case of buccal and alveolar mucosal NHL with invasion into the mandible in a 65-year-old male patient, which was successfully treated by combined surgery and chemotherapy. The patient received total excision of the tumor and modified radical neck dissection. Histological examination of the surgical specimen revealed a tumor composed of sheets of large polygonal blue cells with vesicular nuclei, prominent nucleoli, and active mitotic figures. Immunohistochemical study demonstrated that the tumor cells were diffusely and strongly positive for CD20 (a B-cell marker) and moderately positive for CD138 (a plasma cell marker) but were negative for CD3 (a T-cell marker) and cytokeratin (AE1/AE3). A diffuse large B-cell lymphoma was diagnosed. The patient was subsequently treated with 6 courses of chemotherapy using R-CHOP regimen (rituximab, cyclophosphamide, hydroxydoxorubicin, oncovin, and prednisolone). The postoperative and chemotherapeutic course was smooth, and no recurrence was found 6 months after the initial surgery.

Expression of c- myc, erbB-2, p53 and nm23-H1 gene product in benign and malignant breast lesions: coexpression and correlation with clinicopathologic parameters

The aims of this study were to assess the expression of protein products of c- myc, erbB-2, p53 and nm23-H1 gene in benign and malignant breast lesions, to estimate their possible coexpression and to correlate the results of immunohistochemical analysis with various clinicopathologic parameters. The method used was the immunohistochemical detection of the corresponding protein. Expression of c- myc protein was high in both malignant and benign lesions (95% and 100%). Expression of erbB-2 and mutated p53 proteins in malignant lesions was 27% and 34%. These proteins were present in benign lesions as well: 7.8% of benign lesions were positive for erbB-2 protein and 19.6% for p53 protein. The expression of nm23-H1 protein was similar in benign and malignant lesions: 47% and 54%. The coexpression of nm23-H1 and mutated p53 protein was found in 14 carcinomas (16.5%). We found a tendency of negative correlation between the expression of these two proteins. We also found a negative correlation between the size of breast carcinomas and the expression of nm23-H1, a higher proportion of nm23-H1-positive carcinomas in the group of erbB-2-negative, p53-negative carcinomas and a higher proportion of nm23-H1-positive carcinomas in the group of malignant lesions with negative axillary lymph nodes. Our results support the hypothesis that in women with breast cancer the expression of nm23-H1 gene may contribute to more favorable phenotype. We also showed that some changes found in malignant breast tumors such as the presence of mutated p53 protein and the expression of erbB-2 protein may be found in benign lesions as well.

Localized B-cell non-Hodgkin's lymphoma of oral cavity and maxillofacial region: A clinical study

Objective Non-Hodgkin's lymphomas (NHL) are the third most common group of malignant lesions in the oral cavity and maxillofacial region. Most such lymphomas have been shown to be predominantly of B-lineage. The purpose of the present study is to analyze the clinical signs and symptoms and the clinical staging of B-cell NHL of this region. Study design Eighteen adults, with B-cell NHL manifestations of the oral cavity and maxillofacial region, were available for this study. The clinical stage according to the Ann Arbor system was assessed by history, physical, and laboratory examination. Hematoxylin and eosin–stained slides and paraffin blocks were available for all cases. Histologic diagnosis was based on the WHO classification of tumors. Results The mean age of patients at the time of biopsy was 64 years. At the time of the disease presentation, according to the Ann Arbor system, 11 patients were in stage I E, 2 patients in stage II E, 2 patients in stage III E, 1 patient in stage IV E, and 2 patients in stage IV. The typical clinical appearance was a painless local mass lateral or bilateral. Often there is a superficial ulceration of the tumor mass. Tonsillar NHL was the most frequent site occurring in 8 patients followed by NHL of the oral cavity, of the salivary glands, and of the mandible. Grading revealed that most cases were high grade (11 cases), followed by the cases of low grade (5 cases) and intermediate grade (2 cases). All the different histologic types may be observed, but the most frequently encountered is the diffuse large type. Conclusions The B-cell NHL may involve both osseous and soft tissues of the oral cavity and maxillofacial region. The favored sites are tonsils, palatal mucosa and parotid glands. The typical clinical appearance is a painless local mass lateral or bilateral. Often there is a superficial ulceration of the tumor mass. According to the Ann Arbor system, the majority of the cases at the time of diagnosis are in stage I or II. Most patients have high grade disease. All the different histologic types may be observed, but the most frequently encountered is the diffuse large type.

Intravascular papillary endothelial hyperplasia (Masson's tumor) of the oral mucosa. Presentation of two cases and review

Intravascular papillary endothelial hyperplasia (Masson's tumor) is a benign lesion of the skin and subcutaneous tissue consisting of a reactive proliferation of endothelial cells with papillary formations related to a thrombus. The clinical picture is not specific and the diagnosis is based on histological examination. The lesion is often mistaken with angiosarcoma and a group of other benign and malignant vascular lesions. The presentation in the oral mucosa and lips is rare. Two new cases located in the lower lip and buccal mucosa are presented and a review in accessible literature is made.

Benign and malignant breast lesions: diagnosis with multiparametric MR imaging.

To both develop and use a tissue signature method for the identification and classification of breast lesions and healthy breast tissue with magnetic resonance (MR) imaging. Thirty-six patients underwent breast MR imaging (T1- and T2-weighted imaging and three-dimensional T1-weighted imaging with and without contrast material enhancement), followed by biopsy or mastectomy and histopathologic analysis. Tissue cluster analysis was performed by using the iterative self-organizing data technique to identify glandular, adipose, and lesion tissue signature vectors. Glandular and lesion tissue vectors were characterized by angular separation from the reference adipose tissue vector. Differences in angular separation of histologically proved benign and malignant lesion groups were evaluated with an independent t test. The usefulness of the angular separation model for distinguishing benign from malignant lesions was evaluated with nonparametric receiver operating characteristic curve analysis. The model enabled successful identification and characterization of breast lesion tissue clusters in all patients; 18 lesions were benign, and 18 were malignant. Angular separation +/- SD was 17.8 degrees +/- 6.1 degrees between adipose tissue and malignant lesions and 29.0 degrees +/- 11.2 degrees between adipose tissue and benign lesions. Angular separations of benign lesions and malignant lesions were significantly different (P =.002), with a specificity of 78% and sensitivity of 89% at a cutoff value of 21 degrees. Significant differences in angular separation from adipose tissue also were found between glandular tissue and lesion tissue (P <.001) and, in glandular tissue, between patients with benign lesions and those with malignant lesions (P =.04). The area under the receiver operating characteristic curve was 0.84. Multispectral analysis of conventional breast MR images based on the iterative self-organizing data model and on measurement of angular separation between tissue signature vectors may enable automated lesion identification and classification.

Spread of a recurrent lentigo maligna into a graft: a case for conservative treatment

Lentigo maligna is an in situ malignant melanoma for which the treatment of choice is surgical excision. The recurrence rate in lentigo maligna is high and hence other treatments, such as cryotherapy, laser therapy, radiotherapy and Mohs' chemosurgery, have been described. Despite the high recurrence rate, spread of a lentigo maligna into a skin graft is rare. We describe a case of a recurrent lentigo maligna spreading into a skin graft, which, along with the cases described in the literature, highlights the presence of a group of low-grade malignant lentiginous lesions that may be managed by careful follow-up and observation.

Human in-vivo 31P MR spectroscopy of benign and malignant breast tumors.

ObjectiveTo assess the potential clinical utility of in-vivo 31P magnetic resonance spectroscopy (MRS) in patients with various malignant and benign breast lesions.Materials and MethodsSeventeen patients with untreated primary malignant breast lesions (group I), eight patients with untreated benign breast lesions (group II) and seven normal breasts (group III) were included in this study. In-vivo 31P MRS was performed using a 1.5 Tesla MR scanner. Because of the characteristics of the coil, the volume of the tumor had to exceed 12 cc (3×2×2 cm), with a superoinferior diameter at least 3 cm. Mean and standard deviations of each metabolite were calculated and metabolite ratios, such as PME/PCr, PDE/PCr, T-ATP/PCr and PCr/T-ATP were calculated and statistically analyzed.ResultsSignificant differences in PME were noted between groups I and III (p=0.0213), and between groups II and III (p=0.0213). The metabolite ratios which showed significant differences were PME/PCr (between groups II and III) (p=0.0201), PDE/PCr (between groups I and III, and between groups II and III) (p=0.0172), T-ATP/PCr (between groups II and III) (p=0.0287), and PCr/T-ATP (between groups II and III) (p=0.0287). There were no significant parameters between groups I and II.ConclusionIn-vivo 31P MRS is not helpful for establishing a differential diagnosis between benign and malignant breast lesions, at least with relatively large lesions greater than 3 cm in one or more dimensions.

Over-expression of hepatocyte growth factor/scatter factor (HGF/SF) and the HGF/SF receptor (cMET) are associated with a high risk of metastasis and recurrence for children and young adults with papillary thyroid carcinoma.

The study determined if hepatocyte growth factor/scatter factor (HGF/SF) or the HGF/SF receptor (cMET) might be important for metastasis in thyroid cancer. We examined HGF/SF and cMET expression by immunohistochemistry in a retrospective group of benign and malignant thyroid lesions from children and young adults, and correlated the intensity of expression with clinical outcome. Patients included 42 children and young adults with papillary thyroid carcinomas (PTC), seven with follicular thyroid carcinomas (FTC), two with medullary thyroid carcinomas (MTC), 14 with benign thyroid disorders, and two with normal thyroids. Expression of cMET was graded from 0 (absent) to 4 (intense); and HGF/SF expression was graded from 0 (absent-minimal) to 3 (diffuse and intense). cMET staining was greater in PTC (mean intensity 2.3 +/- 0.4 vs. 0.8 +/- 0.2, P < 0.005) and FTC (2.4 +/- 0.6 vs. 0.8 +/- 0.2, P = 0.04) than benign lesions (0.8 +/- 0.2) or normal thyroids (0.4 +/- 0.5). PTC with intense cMET staining had shorter disease free survival (P = 0.05) and increased HGF/SF staining (r = 0.39, P = 0.017). HGF/SF correlated with the extent of disease at diagnosis (r = 0.33, P = 0.049). Patients with PTC were stratified into quartiles based on combined cMET and HGF/SF staining. Those with intense cMET and HGF/SF staining were younger (P = 0.05), and had reduced disease free survival (P = 0.03). We conclude that increased cMET and HGF/SF expression is associated with a high risk for metastasis and recurrence in children and young adults with papillary thyroid carcinoma.

A case of misdiagnosis of liver cancer with metastases in a patient with systemic vasculitis

In the group of malignant liver lesions, the frequency of occurrence of metastatic lesions is in the first place. It is distinguished by a pronounced variety of the echographic picture. However, not always a vivid picture of focal lesion corresponds to a true metastatic lesion. The presented observation can serve as an example of such a situation.

Expression of bone sialoprotein in human lung cancer.

Lung cancer belongs to the group of malignant lesions that specifically select bone as secondary implantation site. The molecular bases for this property, defined as osteotropism, is still largely unknown. The recent demonstration that human breast cancer cells express and attach to bone sialoprotein (BSP), a sulfated phosphoprotein rich in bone and other mineralized tissues, could provide a clue to elucidating bone metastases formation. BSP contains the integrin binding peptide Arg-Gly-Asp (RGD), as well as non-RGD cell attachment domain. Using an immunoperoxidase technique and a specific polyclonal antibody directed against a BSP synthetic peptide, we examined the expression of BSP in 48 lung lesions including 25 squamous carcinoma, 21 adenocarcinoma, and 2 bronchioloalveolar cancers, as well as 38 human ovarian carcinoma that constitute a group of generally nonosteotropic cancers. BSP was not specifically detected in normal lung tissue with the exception of cartilage associated with bronchi. Most of the adenocarcinoma (74%) and all squamous carcinoma of the lung examined exhibited detectable levels of BSP. Staining was mainly cytoplasmic and membrane associated. The two bronchioloalveolar lung cancers examined did not show detectable amounts of BSP. When microcalcifications were observed in pulmonary malignant lesions, they were usually associated with cancer cells expressing BSP. Only 21% of the ovarian cancers examined contained malignant cells with 2+ or 3+ positivity for BSP. We further demonstrated that in 8 of 10 additional lung cancers, BSP was detected at the mRNA level. Our observation is the first demonstration that BSP is expressed in non-small cell lung carcinoma. Lung cancer cells are now the second type of osteotropic malignant cells described to express BSP. Added to the observation that BSP expression is not frequent in ovarian carcinoma, a low osteotropic cancer, our study supports our hypothesis that BSP could play a role in determining the affinity of cancer cells to bone.

Fibromatosis and fibrosarcoma in infancy and childhood.

INTRODUCTION NEOPLASMS AND pseudoneoplastic proliferations of fibroblasts and myofibroblasts form a large group of benign and malignant lesions which present as subcutaneous or deep tumour masses, often with alarmingly rapid growth. They display varying degrees of cellularity, collagen production and maturation to smooth muscle (Table l), and to some extent, they overlap with those in which there are also histiocyte-like features, the so-called fibrohistiocytic tumours [l, 21. Advances in histological techniques and contributions from cytogenetics and molecular genetics have enabled more accurate diagnosis, and changed our concepts of some established tumour types, while careful clinicopathological observations have defined the incidence and natural history of each entity. A number of these tumours are peculiar to younger age groups. Other tumours are found throughout life, but when occurring in infancy and childhood behave differently from the identical lesion in adults, with a benign outcome sometimes belying apparently aggressive histology. This is particularly so for the fibromatoses and fibrosarcoma, which form the subject of this review.

The role of radiolabeled somatostatin analogs in adrenal imaging

We investigated the role of radiolabeled somatostatin analogs (SAs) in adrenal imaging. We evaluated 15 patients (6 men and 9 women, mean age 47 ± 17 years) with imaging-detected adrenal tumors. Patient population was divided into two groups on the basis of the nature of adrenal lesions. Group 1 consisted of patients with benign adrenal lesions ( n = 10). Group 2 consisted of patients with malignant adrenal lesions ( n = 5). Pathology examinations were obtained in 13 cases: 7 pheochromocytomas, 2 adenomas, 2 cysts, 1 carcinoma, and 1 fibro-histiocytoma. One patient had a proven diagnosis of non-small-cell lung cancer associated with the presence of a right adrenal mass. The last patient had a clinical diagnosis of Werner syndrome associated with the presence of a large left adrenal mass. All patients underwent scintigraphic studies using radiolabeled SAs, of which indium-111 (In-111) pentetreotide was used in 11 cases and technetium-99m (Tc-99m)-labeled peptides (P-587 or P-829) were used in the remaining four cases. No significant labeled SAs uptake was observed in the majority (8 of 10, 80%) of the benign adrenal lesions (Group 1); however, increased uptake was found in two benign pheochromocytomas. Conversely, significant labeled SAs uptake was observed in the majority (4 of 5, 80%) of the malignant adrenal lesions (Group 2); however, the last lesion (carcinoma) did not show abnormal uptake. Results of this study show that the majority of benign adrenal tumors do not concentrate radiolabeled SAs; conversely, the majority of malignant adrenal lesions show significant SAs uptake, suggesting the presence of somatostatin receptors. This finding may allow the use of somatostatin as a treatment agent in malignant adrenal tumors. Thus, the main role of labeled SAs in adrenal imaging consists of lesion characterization rather than tumor detection and localization.

Reconstruction Using the Saddle Prosthesis Following Excision of Primary and Metastatic Periacetabular Tumors

From 1988 to 1991, 17 patients with malignant periacetabular tumors underwent limb-sparing surgery and reconstruction using the saddle prosthesis. There were 8 patients with primary malignant lesions (Group 1), and 9 patients with metastatic or systemic tumor involving the periacetabular pelvis (Group 2). All resections included excision of the acetabulum. Patients ranged in age from 24 to 76 years (average, 59.8 years). Local control was achieved in all patients. Wide margins were obtained in all patients with primary pelvic tumors. Functional outcomes were rated as follows excellent (10), good (2), fair (1), and poor (4). Three patients, all of whom had pulmonary metastasis before surgery, died within 8 months of surgery. Of the remaining 14 patients, 5 patients died between 6 and 28 months after the index procedure. At the end of the followup period, 9 patients were still alive (6 in Group 1 and 3 in Group 2), with a followup period ranging from 15 to 62 months (average, 33.4 months). The overall results for surviving patients were 7 excellent and 2 good results, with no fair or poor results.

Bone marrow diseases of the spine: differentiation with T1 and T2 relaxation times in MR imaging.

Forty-two patients underwent magnetic resonance (MR) imaging for a variety of lesions in the vertebral body. A 0.15-T MR system was employed. Twenty-six patients were found to have malignant metastatic lesions (group 1); 16 had nonneoplastic lesions (group 2). The ability to differentiate between the two groups with MR imaging was evaluated. With the longer spin-echo repetition time, the image was variable in both groups. All malignant metastatic lesions appeared as low-intensity areas on T1-weighted images, but 50% of the nonneoplastic lesions also appeared this way. The mean T1 for group 1 was longer than that for group 2, but not significantly so. However, there were significant differences in the ratios of T1 to T2 and of the T1 ratio to the T2 ratio (T1 ratio = T1 for affected vertebrae/T1 for normal vertebrae, T2 ratio = T2 for affected vertebrae/T2 for normal vertebrae). These ratios were therefore useful in distinguishing malignant metastatic from nonneoplastic lesions.

Malignant Histiocytomas

During the past ten years, the histiogenesis of malignant histiocytomas and a group of related benign and malignant lesions have been the source of speculation. Although of heterogeneous histological appearance, it is believed that there is a common cell of origin for these neoplasms--the histiocyte. From 1966 to 1974, 16 patients were encountered who had neoplasms that fell into the general group of malignant histiocytomas. These tumors were variously located in the extremities, head, chest wall, retroperitoneum, lung, spermatic cord, and lower abdomen. Surgical treatment included radical amputations, wide local excision, pulmonary lobectomy, and nephrectomy. Cobalt therapy and chemotherapy with vincristine sulfate, cyclophosphamide, doxorubicin hydrochloride, and chlorambucil were also used. Ten of 16 patients are alive after treatment, two are alive with metastatic disease, but four have died of malignant disease.