Cases Of Soft Tissue Tumors Research Articles

Gastrointestinal stromal tumors (GIST): Evaluation of malignancy and prognosis in 113 cases retrieved from a population based Cancer Registry of Northern Italy

4232 Background: The definition of gastrointestinal stromal tumors (GIST) has evolved over time and its true incidence is still unknown, probably underestimated. We have reviewed 161 cases of soft tissue tumors of the GI diagnosed in the province of Modena between 1988 and 2002 and registered in the Modena Cancer Registry, with the aim of establish the true incidence and the clinical behavior of the disease. Methods: Diagnostic samples were investigated by ICC for CD117 (Dako), PDGFR-A (Santa Cruz) actin, desmin, S100, and CD34. Cases were classified as GIST if resulted KIT+/PDGFR-A- or KIT-/PDGFR-A+.The tumor behavior was assessed on the basis of tumor size and mitotic count, according to the Consensus panel. Results: The diagnosis of GIST was confirmed in 113 cases, 98 KIT+ (87%) and 15 KIT- (13%). The incidence of GIST was of 13 cases per million inhabitants/year. The GIST identified in our population represent 1,1% of all GI cancers diagnosed in the last 15 years. Fifty seven (50%) were men and 56 (50%) women. Median age at diagnosis was 67 years. Sixty four tumors (57%) arose in the stomach. The risk of aggressive behavior was very low, low, intermediate or high in 13%, 12%, 19%, and 55% of cases, respectively. The most frequent symptoms were abdominal pain (37%) and GI bleeding (21%). Twenty one patients (19%) were asymptomatic. Eighty-six patients (76%) underwent radical surgery. After a median follow-up of 46 months (68 months for pts alive) the 5-year survival rate was 53%. At the same interval the survival rate was 75%, 70% and 72% for patients at very low, low and intermediate risk, and 42% for those at high risk (P = 0.0065). The 5-year relapse-free survival rate after radical surgery of primary GIST was 94% for patients at very low, low and intermediate risk, and 43% for patients at high risk (P < 0.0001). Conclusions: GIST represent a rare but well recognizable disease. The risk of aggressive behavior is high in more than 50% of cases. The finding that after radical surgery all relapses but two occurred in patients classified at high risk of aggressive behavior, confirms the clinical usefulness of the Consensus approach. No significant financial relationships to disclose.

当科における手の腫よう症例の検討

We analyzed 58 cases of hand tumor for which histopathological diagnosis was established in the 10 years from 1993 to 2002. Ganglions developed in soft tissue were excluded. They consisted of 25 cases of bone tumor and 33 cases of soft tissue tumor. Age range was 6 to 78 years and mean age was 26. 1 years. Of the 30 cases of benign soft tissue tumor, nine cases had giant cell tumor of the tendon sheath, eight cases hemangeoma, three cases neurilemmoma, two cases of tenosynovial chondromatosis in order of frequency. There were three cases of malignant soft tissue tumors that were malignant fibrous histiocytima, liposarcoma, and epithlioid sarcoma, respectively.The 25 cases of bone tumors, consisted of 16 cases of enchondroma, three cases of osteochondroma, two cases of intraosseous ganglion, two cases of periosteal chondroma, one case of aneurismal bone cyst, and one case of giant cell reparative granuloma. There were no malignant bone tumors in this series.As the favorite region, soft tissue tumors were noted in the finger region (61%), palm region of the hand (27%), wrist region (9%) and back region of the hand (3%). Bone tumors were noted in the phalanges (64%), metacarpals (32%), and carpals (4%). Soft tissue tumors and bone tumors developed most often in the finger regions.Recurrence was seen in one case of giant cell reparative granuloma, and case of epithlioid sarcoma, none in other soft tissue tumors and bone tumors.Benign soft tissue tumors treated with marginal excision and benign bone tumors treated with curettage and autologous bone transplantation showed good results, however, it was difficult to treat malignant soft tissue tumors without recurrence.

The MRI Features and Treatment of Scapulothoracic Bursitis: Report of Four Cases

Among cases of soft tissue tumours arising between the inferior angle of the scapula and thoracic wall, scapulothoracic bursitis has rarely been reported. All the reported cases were surgically treated and there have been no reports about the results of conservative treatment observed for a long period. Therefore, we retrospectively evaluated the clinical findings, magnetic resonance imaging (MRI) features, and treatment procedures in order to elucidate the differential diagnosis for, and efficacy of, conservative treatment. The patients were those who consulted our department of orthopedic surgery from 1994 to 1998 with complaints of thoracic back tumours. The patients were 2 men and 2 women whose ages ranged from 46 to 66 years. The tumour locations, MRI findings and treatments were evaluated. The cysts appeared in the inferior angle of the scapula with the shoulder flexed and adducted. There was neither pain nor tenderness, local heat nor redness. The cysts were elastic hard, fluctuating, and less mobile and the margins were well circumscribed by palpation. The diameters were from 6 x 6 cm to 20 x 15 cm. On MR imaging, the cysts were located between the serratus anterior muscle and the chest wall. Slightly high signal intensity on T1WI, high on T2WI and fluid-fluid levels were seen in the cysts in three cases. For the treatment, in one case we performed multiple aspirations until a reduction appeared to occur. The average aspirated contents of the cyst were 100 mL to 200 mL and were bloody-serous. In two cases no special treatments were employed, and in one case the tumour was surgically removed because it was unresponsive to aspiration. In the three cases with conservative treatment, the follow-up time was 8, 9 and 25 months, respectively. The tumours had disappeared in all cases at the time of the final follow-up. High signal intensities on T1 and T2 weighted images, and fluid-fluid level on T2 weighted images were very useful MRI features for the diagnosis of scapulothoracic bursitis. Our observations indicate that conservative treatment can be successful and surgery is not necessary except for cases with pain, excessive friction, or dysfunction.

Bone and soft tissue tumours of the foot: review of 83 cases.

To review cases of bone and soft tissue tumours of the feet managed at the Hyogo College of Medicine, Nishinomiya and Takarazuka Municipal Hospital, Takarazuka, Japan. Retrospective analysis of 83 patient records treated for bone and soft tissue tumours of the feet between 1974 and 2000. There were 33 benign bone tumours, one primary malignant bone tumour, and 2 metastatic bone cancer. Marginal resection was performed in cases of osteochondroma and curettage in cases of other benign bone tumour. Despite below-knee amputation in the case of chondrosarcoma, the patient died because of pulmonary metastasis. Two patients with metastatic cancer also died, and 2 cases of osteochondroma and one of benign chondroblastoma recurred. There were 47 cases of soft tissue tumour. Treatment for benign soft tissue tumours was marginal resection; no cases recurred. In contrast, all patients with soft tissue sarcoma died after surgery. The majority of bone tumours were located in the toe and hindfoot areas, in the first and second decades of life, whereas soft tissue tumours occurred mainly in the midfoot area and in patients aged between 20 and 50 years. The sex distribution was almost even for bone tumours (male: female ratio, 19:17), whereas about half as many males as females had soft tissue tumours (14:33). Bone and soft tissue tumours of the feet are uncommon. Most bone tumours are chondrogenic, but differential diagnosis of malignant from benign disease is difficult and prognosis is poor. Management of benign tumours by marginal resection has good prognosis, whereas prognosis of soft tissue sarcomas is very poor.

画像上のＦｌｕｉｄ‐Ｆｌｕｉｄ Ｌｅｖｅｌを認めた骨・軟部腫ようの検討

To assess the diagnostic significance of the fluid-fluid level (FFL), we reviewed CT and MRI findings of bone and soft tissue tumors exhibiting FFL literature. For the past 10 years, the formation of FFL was reported in 14 of 110 cases of bone and soft tissue tumors. These 14 cases consisted of 8 case of bone tumors (5 of 6 cases of aneurysmal bone cyst, 1 case of chondroblastoma, 1 of 3 cases of intraosseous ganglion, and 1 of 2 cases of fibrous dysplasia) and 6 cases of soft tissue tumors (2 of 21 cases of malignant fibrous histiocytoma, 1 of 14 cases of schwannoma, 1 of 13 cases of hemangioma, 1 of 5 cases of pigmented villonodular synovitis).FFL was most frequently detected by T2-weighted MR images. When FFL is formed by hemorrhagic contents of the cyst, the upper layer showed a higher intensity than the lower layer. Because FFL was observed in various types of bone and soft tissue tumors regardless of their benignancy or malignancy, the diagnostic significance of FFL may be limited. However, FFL was a characteristic feature of aneurysmal bone cyst, because it was observed in 5 of 6 cases of these cysts.

Clinical outcome of total scapulectomy in 10 patients with primary malignant bone and soft-tissue tumors.

Limb reconstruction after total scapulectomy for malignant bone and soft-tissue tumors around the scapula is difficult. This study was undertaken to clarify the clinical results of total scapulectomy in patients with malignant bone and soft-tissue tumors around the shoulder girdle in our institute between 1984 and 1998. Ten patients undergoing total scapulectomy had an age range of 12-82 years (average = 56 years). There were 5 cases of bone tumor and 5 cases of soft-tissue tumor. The follow-up period ranged from 8 months to 13 years 5 months. Seven patients are currently alive; the remaining 3 patients died of other diseases. One case of local recurrence was detected. The 2-year survival rate of all cases was 78.8%, and the 5-year survival rate was 52.5%. The average function evaluated by Enneking's criteria was 64.6%. Although the range of motion in the shoulder joint was seriously limited in all patients, the elbow and hand functions were almost normal. Recently, we have used a bone-anchoring system to suture between the clavicle and muscles, including the biceps, triceps, and deltoid muscles. Patients who undergo total scapulectomy may achieve much better upper limb function than those who undergo forequarter amputation (interscapulothoracic amputation).

術前，良性・悪性の判定が困難であった，鼠径部，えきか部に発生した軟部腫りゅうの２例

We reported two cases of soft tissue tumor whose diagnosis was difficult to determine as whether malignant or benign in preoperative examinations.1 case was a 70-year-old female. 2 painless soft tissue masses 10cm and 3cm in diameter were found in her left inguinal region. Magnetic resonance imaging (MRI) demonstrated clear border without adhesion to the surrounding tissues. No typical tumor atain was obtained on angiogram. Although a needle biopsy demonstrated no evidence of malignancy, postoperative diagnosis was malignant lymphoma, non-Hodgkin myxoid cell type.The other case was a 53-years-old male. A painless soft tissue mass 5cm in diameter was found in his left axillary region, MRI demonstrated clear border without adhesion to the surrounding tissues. Gadolinium enhanced images demonstrated low to high intensity specles, which suggested neurilemoma. The biopsy specimen showed neurological cells and no evidence of malignancy. Post operative diagnosis was benign neurilemoma.We concluded that preoperative image examinations for example MRI provides considerable reference for surgical location, which was however insufficient for histological diagnosis, and a study on the false-negative of the histology by needle biopsy was necessary for preoperative diagnosis. Laboratory data is also important for cases of malignant lymphoma prior to operation.

Cell-type- and tumour-type-related patterns of bcl-2 reactivity in mesenchymal cells and soft tissue tumours.

Bcl-2 is one of the many proteins that regulate programmed cell death and is overexpressed in B-cell lymphomas. The expression of bcl-2 in mesenchymal cells and soft tissue tumours was the subject of this study. Normal mesenchymal tissue and representative cases of soft tissue tumours of different types (n>200) were investigated immunohistochemically for bcl-2 expression. Although bcl-2 expression was normally relatively restricted to some smooth muscle cells and neural cells, bcl-2 immunoreactivity was widespread in different types of soft tissue neoplasms, both benign and malignant. Consistently positive tumours included solitary fibrous tumour, haemangiopericytoma, schwannoma and synovial sarcoma. The few soft tissue tumours that were consistently negative for bcl-2 included nodular fasciitis and desmoid tumour. Leiomyomas and leiomyosarcomas were heterogeneous; all uterine leiomyomas were bcl-2 positive, but all oesophageal leiomyomas were negative, paralleling the reactivity observed in the smooth muscle at those sites. Gastrointestinal stromal tumours showed bcl-2 reactivity; this was less consistent in malignant tumours. Along the malignancy gradient, there was no consistent trend in the bcl-2 reactivity. Dermatofibrosarcomas showed increase of bcl-2 expression with fibrosarcomatous transformation, whereas smooth muscle sarcomas and malignant peripheral nerve sheath sarcomas were less consistently positive than the corresponding benign neoplasms. We conclude that bcl-2 expression is widespread in soft tissue tumours, but shows constitutional expression patterns that are often parallel to the normal tissue counterparts. Compared with benign soft tissue tumours, bcl-2 expression is often reduced in sarcomas, but it cannot be used as a prognostic marker without correlation of the data to its phenotypic expression patterns.

Supernumerary ring chromosomes and nuclear blebs in some low-grade malignant soft tissue tumours: atypical lipomatous tumours and dermatofibrosarcoma protuberans.

We investigated the diagnostic significance of supernumerary ring chromosomes in low-grade soft-tissue neoplasms. Chromosome slides were prepared from 123 samples of soft-tissue tumours using the standard trypsin-Giemsa banding technique. Supernumerary ring chromosomes were found in 6 cases of soft tissue tumours: 5 cases of atypical lipomatous tumour (ALT) and 1 case of dermatofibrosarcoma protuberans (DFSP). By chromosome painting with fluorescence in situ hybridization (FISH), the ring chromosome in 1 ALT was painted over its entire length with the chromosome 12 probe. Nuclear blebs and micronuclei, which were observed in each case of ALT, also contained chromosome 12 material; and these structures may represent a topological distribution of ring or giant marker chromosomes in the interphase nuclei. Our findings suggest that supernumerary ring chromosomes are characteristic of some low-grade soft tissue neoplasms including ALT and DFSP.

まれな鼻腔腫ようの２例

Two cases of soft tissue tumors of the nasal cavity were reported, a solitary fibrous tumor (SFT) and a schwannoma. A 61-year-old woman had a 3-year history of right nasal obstruction. Her right nasal cavity was occupied by a large tumor. MRI revealed the tumor had invaded the ethmoid cells. Total resection was achieved through the extended Denker's operation. The tumor was immunohistochemically positive for vimentin and CD34 and pathologically diagnosed SFT. This is the fourth reported case of a SFT in the region of the nasal cavity, paranasal sinuses and nasopharynx in Japan. SFTs sometimes show aggressive behavior and recurrences, necessitating careful follow-up.A 72-year-old woman had a 5-year history of left nasal obstruction. Her nasal cavity was obstructed by a tumor and MRI revealed that the tumor arose from the anterior wall of the sphenoid sinus. The tumor was removed endoscopically and pathologically diagnosed as a schwannoma.Soft tissue tumors of the nasal cavity are pathologically classified into 22 categories and their occurrence is rare. It is sufficiently difficult to accurately diagnose these tumors by H-E staining that immunohistochemical study is useful to confirm the histological origins

Tumors of the foot and ankle: Analysis 196 cases

A retrospective assessment was performed on 196 tumors of the foot and ankle [out of 1786 bone and soft tissue tumor cases, (10.9%)] between March 1986 and March 1996 in the Ankara University Department of Orthopedics and Traumatology Tumor Section. Mean age was 28 years (range 3 to 75 years). Of the 196 foot and ankle tumor cases, 171 (87.2%) were benign, and 25 (12.8%) were malignant. One hundred ninety-four (98.9%) were primary tumors and 2 (1.1%) were metastatic tumors. One hundred thirty-six (69.4%) originated from bone, whereas 60 (30.6%) originated from soft tissue. The most frequent foot and ankle tumors were osteosarcoma among malignant osseous tumors, squamous cell carcinoma among malignant soft tissue lesions, solitary exostosis among benign osseous tumors, and xanthoma and giant cell tumor among benign soft tissue tumors. Mean follow-up time was 21.3 months (12 to 90 months). One hundred forty (71.4%) of the patients underwent various operations while the remaining 56 (28.6%) were treated conservatively. Of the 140 surgical cases, 13 (9.3%) had a recurrence, 3 (2.1%) died, and 124 (88.6%) had a clinical cure. For most of the patients who required surgery, nonaggressive procedures were sufficient while amputations were required for 14 patients.

P53 gene mutations in soft-tissue sarcomas--correlations with p53 immunohistochemistry and DNA ploidy.

The significance of p53 mutations in a group of 67 soft-tissue tumors was examined using single-strand conformation polymorphism and direct sequencing analysis. Molecular findings were correlated with immunohistochemical detection of the p53 protein and DNA ploidy status. Mutations of the p53 gene were detected in 13 (19.5%) out of 67 cases of soft-tissue tumors. Only three were localized outside the conservative regions of the p53 gene. Six mutations were described for the first time in these tumors. Most of the mutations were point mutations in exons 5-8 and, in one case, a deletion at the 3'-splice site of exon 5 could be demonstrated. There was no significant correlation between the occurrence of p53 mutations and the histological grade, although a high number of mutations were defined in poorly differentiated tumors (grade 3). Molecular finding of a p53 gene mutation and immunohistochemical detection of p53 expression did not correlate, which may be due to the high percentage of nonsense mutations in our study (50%). We confirm that only DNA sequencing allows a unique identification and differentiation of mutations in the p53 gene. Other factors may be responsible for the detection of p53 protein in many cases. Histological grade correlated with aneuploidy. The frequency of mutations observed was in accordance with values quoted in the literature. Generally, p53 mutations and p53 overexpression are more likely to represent a late event in the oncogenesis of soft-tissue tumors.

DER(16)T(1-16) IS A NONRANDOM SECONDARY CHROMOSOME ABERRATION IN MANY TYPES OF HUMAN NEOPLASIA, INCLUDING MYXOID LIPOSARCOMA, RHABDOMYOSARCOMA AND PHILADELPHIA-CHROMOSOME-POSITIVE ACUTE LYMPHOBLASTIC-LEUKEMIA

An unbalanced translocation between chromosomes 1 and 16, der(16)t(1;16), resulting in trisomy 1q and loss of genetic material from 16q, has been thus far suggested to constitute a nonrandom secondary abnormality in two types of closely related solid tumors - Ewing sarcoma and peripheral primitive neuroepithelial tumor (PNET). We report on three cases of soft tissue tumors, a myxoid liposarcoma, a PNET and a rhabdomyosarcoma, and four cases of hematologic disorders, two acute lymphoblastic leukemias (ALL), an acute mixed leukemia and a refractory anemia, that in addition to primary chromosome abnormalities displayed the presence of the der(16)t(1;16). All three cases of acute leukemia were Philadelphia (Ph) chromosome-positive and all displayed both lymphoid and myeloid antigens. Our results and review of the literature indicate that the occurrence of der(16)t(1;16) is not limited to Ewing sarcoma and PNET, but that acquisition of this abnormality may represent a more general pathway of clonal evolution in several different tumor types including Ph chromosome-positive ALL, myxoid liposarcoma, rhabdomyosarcoma, breast cancer, endometrial adenocarcinoma, myelodysplastic syndromes, acute myeloid leukemia, retinoblastoma, and Wilms' tumor.

Assessment of proliferating-cell nuclear antigen immunostaining in soft-tissue tumours: relationship to histological grade and mitotic activity.

The proliferative activity in 70 cases of soft-tissue tumours was estimated immunohistochemically using the monoclonal antibody PC-10, which recognizes proliferating-cell nuclear antigen (PCNA) in paraffin sections. The PCNA index (i.e. the percentage of positive neoplastic nuclei) and to a lesser degree the PCNA count (i.e. the number of positive neoplastic nuclei per ten high-power fields) positively correlated with the malignancy grade (PCNA index: P < 0.001; PCNA count: P < 0.01). However, the range of values of PCNA index and PCNA count was similar between benign and grade I tumours. A statistically significant positive correlation was also established between PCNA index and PCNA count on the one hand and mitotic count on the other, but the correlation coefficient was low (r = 0.351, P < 0.01, and r = 0.290, P < 0.05 respectively). These results indicate that PCNA immunostaining may successfully be used as an adjunct to the conventional histopathological parameters in assessing the malignancy grade in soft-tissue tumours although it is of limited value in distinguishing between benign and grade I tumours.

Vimentin-Negative Epithelioid Sarcoma

Virtually all reported cases of epithelioid sarcoma have been vimentin rich, and the coexpression of vimentin and keratin is considered a characteristic immunophenotype in these tumors. We report three cases of soft tissue tumors with histologic and clinical features consistent with epithelioid sarcoma, all of which failed to immunoreact by standard immunohistochemistry for vimentin using two different monoclonal antibodies. Antigen retrieval demonstrated focal vimentin staining in one case, whereas the other two remained negative. An extensive panel of immunohistochemical stains revealed strong diffuse staining with keratin and epithelial membrane antigen in all three cases as well as patchy membrane staining with an antibody to CD34. CD34 positivity is commonly seen in epithelioid sarcoma, but it is very rarely found in carcinomas. We conclude that these cases represent a unique immunophenotypic variant of epithelioid sarcoma that can be immunohistochemically confirmed, despite the lack of identifiable vimentin, by their immunoreactivity for keratin and CD34.

Primitive Neuroectodermal Tumors of Bone and Soft Tissue

Primitive neuroectodermal tumors (PNET) of the bone and soft tissue were reviewed by immunohistochemistry and partly by morphometry, focusing particularly on histologic changes in recurrent or metastatic foci, in order to elucidate their probable histogenetic relationship with Ewing's sarcoma (ES) and its extraskeletal counterpart (EES). Eleven cases of bone tumor (average patient age; 15.1 yr) and 12 cases of soft tissue tumor (average patient age; 22.1 yr) which disclosed unequivocal Homer-Wright rosettes and/or at least foci of ganglion cell differentiation either in a given primary tumor or metastatic (or recurrent) foci were selected from small round cell tumors primarily categorized as ES or EES. Most of the cases for which follow-up biopsy samples were available disclosed prominent Homer-Wright rosettes in the metastases, whereas the primary tumors showed features of ES and lacked rosettes. In only one case, Homer-Wright rosettes were absent in the metastatic tumor. Most cases had been treated by combined intensive chemotherapy and radiotherapy, which might have influenced cell differentiation. Neural markers (neuron-specific enolase, neurofilament protein and others) were positive in most cases. Three cases with otherwise typical histologic features of ES or EES showed minute foci of ganglion cell differentiation, as confirmed by morphometry and neural markers. These results suggest that ES (or EES) and PNET are histogenetically related, but represent different stages of cell differentiation.

Diagnostic and therapeutic problems of soft tissue tumors other than rhabdomyosarcoma in infants under 1 year of age: A clinicopathological study of 34 cases treated at the institut gustave‐roussy

Thirty-four cases of soft tissue tumors (STT) other than rhabdomyosarcoma in infants under 1 year of age were seen in our institution between 1955 and 1985. All were diagnosed initially as malignant tumors except for three cases of fibromatosis, and, thus, they received therapy appropriate at that time. During a recent pathologic review, four were seen to have had hemangioma, six hemangiopericytoma, one hamartoma, seven fibromatosis, eight fibrosarcoma, and eight unclassified sarcomas. Of these 34 cases, the initial histological diagnosis was confirmed in only 17. Sixteen patients were believed to have received inappropriately aggressive therapy; indeed, four of these cases diagnosed prior to 1975 had been benign. Major long-term side effects were seen in 7/16 treated patients (six radiotherapy, one surgery), who, in retrospect, should have received less aggressive treatment. The reasons for these initial errors in diagnosis included doubtful histologic features associated in some cases with alarming clinical presentation. We believe that difficulties still remain in distinguishing benign from malignant STT in this age group by histological examination. Therefore, we urge extreme caution in using aggressive therapy before the diagnosis is certain.

Fibrohistiocytic tumors of soft tissues: An immunohistochemical study of 183 cases

183 cases of soft tissue tumors were studied utilizing the immunoperoxidase technique to demonstrate alpha-1-antitrypsin, ferritin and lysozyme. The series comprises 50 malignant lesions, 34 intermediate malignancy lesions, 99 benign lesions of fibrohistiocytic origin, and 23 malignant tumors of non fibrohistiocytic origin. The actual results of the study are as follows: alpha-1-antitrypsin, ferritin and lysozyme were always absent in 10 fibrosarcomas, 2 liposarcomas, 2 Ewing sarcomas, 3 synovial sarcomas, 4 neurofibrosarcomas, and 2 rhabdomyosarcomas, but in 24 malignant fibrous histiocytomas, 34 cases of dermatofibrosarcoma protuberans and 102 benign fibrohistiocytic lesions, these activities were present in a percentage that ranged between 12% and 38% (average 25%). Differences in the frequency of positive reactions did not occur between benign and malignant fibrohistiocytic lesions. The immunohistological examinations carried out have, therefore, only a very limited value for the practical diagnostic evaluation, but, when positive, are important to clarify the histogenesis of the tumor.

Xeroradiography of soft tissue tumors.

The main features of 300 consecutive cases of soft tissue tumors at xeroradiography were submitted to retrospective evaluation. The parameters assessed were: visibility, density, shape, size, outline and relationships of the lesions. The distribution of each parameter between benign and malignant tumors was evaluated by means of statistical analysis. The xerographic signs of malignancy of soft tissue tumors are reviewed and the typical features of some particular tumors are outlined.

SPINDLE CELL LIPOMA

Spindle cell lipoma is an unusual and special type of lipoma which has been occasionally misdiagnosed as liposarcoma by histopathologic examination. Twelve patients with this benign subcutaneous tumor were selected from about 8,000 cases of soft tissue tumors in our files, and the clinical and pathologic features of this tumor were reviewed and analyzed. The lesion exclusively affected adult males, and the nuchal region was the site of predilection. Microscopically, it is composed of an admixture of mature fat cells and fibroblastic spindle cells, accompanying collagen and reticulin fibers interspersed in a rich mucoid substance. The follow‐up information of the patients has revealed a benign clinical course.