Malignant fibrous histiocytoma of soft tissue. A population-based epidemiologic and prognostic study of 137 patients

Development and external validation of a machine learning model for prediction of survival in undifferentiated pleomorphic sarcoma

PURPOSE

Machine learning (ML) algorithms to predict cancer survival have recently been reported for a number of sarcoma subtypes, but none have investigated undifferentiated pleomorphic sarcoma (UPS). ML is a powerful tool that has the potential to better prognosticate UPS.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was queried for cases of histologically confirmed undifferentiated pleomorphic sarcoma (UPS) (n = 665). Patient, tumor, and treatment characteristics were recorded, and ML models were developed to predict 1-, 3-, and 5-year survival. The best performing ML model was externally validated using an institutional cohort of UPS patients (n = 151).

RESULTS

All ML models performed best at the 1-year time point and worst at the 5-year time point. On internal validation within the SEER cohort, the best models had c-statistics of 0.67-0.69 at the 5-year time point. The Multi-Layer Perceptron Neural Network (MLP) model was the best performing model and used for external validation. Similarly, the MLP model performed best at 1-year and worst at 5-year on external validation with c-statistics of 0.85 and 0.81, respectively. The MLP model was well calibrated on external validation. The MLP model has been made publicly available at https://rachar.shinyapps.io/ups_app/ .

CONCLUSION

Machine learning models perform well for survival prediction in UPS, though this sarcoma subtype may be more difficult to prognosticate than other subtypes. Future studies are needed to further validate the machine learning approach for UPS prognostication.

Nomogram for predicting cancer-specific survival in undifferentiated pleomorphic sarcoma: A Surveillance, Epidemiology, and End Results -based study

INTRODUCTION

The purpose of this study was to construct and validate a nomogram for predicting cancer-specific survival (CSS) in undifferentiated pleomorphic sarcoma (UPS) patients at 3, 5, and 8 years after the diagnosis.

METHODS

Data for UPS patients were extracted from the SEER (Surveillance, Epidemiology, and End Results) database. The patients were randomly divided into a training cohort (70%) and a validation cohort (30%). The backward stepwise Cox regression model was used to select independent prognostic factors. All of the factors were integrated into the nomogram to predict the CSS rates in UPS patients at 3, 5, and 8 years after the diagnosis. The nomogram' s performance was then validated using multiple indicators, including the area under the time-dependent receiver operating characteristic curve (AUC), consistency index (C-index), calibration curve, decision-curve analysis (DCA), integrated discrimination improvement (IDI), and net reclassification improvement (NRI).

RESULTS

This study included 2,009 UPS patients. Ten prognostic factors were identified after analysis of the Cox regression model in the training cohort, which were year of diagnosis, age, race, primary site, histological grade, T, N, M stage, surgery status, and insurance status. The nomogram was then constructed and validated internally and externally. The relatively high C-indexes and AUC values indicated that the nomogram has good discrimination ability. The calibration curves revealed that the nomogram was well calibrated. NRI and IDI values were both improved, indicating that our nomogram was superior to the AJCC (American Joint Committee on Cancer) system. DCA curves demonstrated that the nomogram was clinically useful.

CONCLUSIONS

The first nomogram for predicting the prognosis of UPS patients has been constructed and validated. Its usability and performance showed that the nomogram can be applied to clinical practice. However, further external validation is still needed.

Aggressively progressing primary undifferentiated pleomorphic sarcoma in the eyelid: A case report and review of the literature

RATIONALE

Undifferentiated pleomorphic sarcoma is extremely rare in the head and neck area, and the aggressive nature of this tumor has not been previously described.

PATIENT CONCERNS

Therefore, we report a unique case of a very rapidly growing primary undifferentiated pleomorphic sarcoma in the eyelid. A 67-year-old woman presented with a left lower lid mass. She had no previous history of surgery, skin malignancy, or radiation to the eyelid. On initial presentation, the patient showed a 2 × 1 × 1 cm firm, yellow nodule in the left lower eyelid.

DIAGNOSES

We planned complete surgical removal of the mass; however, the patient was lost to follow-up. One month after the initial visit, the mass had markedly enlarged to 3 × 2.2 × 2.3 cm and a new 2 × 2 × 2 cm mass was observed in the left lower eyelid.

INTERVENTIONS

Complete surgical resection of the tumor was performed with a myocutaneous free flap. At that time, two masses were emerged, which had grown to 8 × 8 × 5 cm.

OUTCOMES

The patient died from sepsis caused by pneumonia 2 months after surgery without evidence of local recurrence.

LESSONS

Primary undifferentiated pleomorphic sarcoma in the eyelid is extremely rare. Surgeons should be aware of this abruptly presenting, rapidly growing primary eyelid tumor and it is essential to excise the tumor completely as soon as possible.

Effect of Non-Hodgkin Lymphoma on Survival in Patients With Malignant Fibrous Histiocytoma, Kaposi Sarcoma, and Sebaceous Carcinoma: A SEER Population-Based Study

OBJECTIVE

To quantify the behavior of dermatofibrosarcoma protuberans (DFSP), malignant fibrous histiocytoma (MFH), Kaposi sarcoma (KS), and sebaceous carcinoma (SC) in patients with a history of non-Hodgkin lymphoma (NHL).

PATIENTS AND METHODS

Subjects with a diagnosis of DFSP, MFH, KS, or SC between 1990 and 2006 were identified in the Surveillance, Epidemiology, and End Results Program database. For each skin cancer type, the standardized mortality ratio (SMR) for death due to any cause and death due to skin cancer was estimated.

RESULTS

From 1990 through 2006, 25,357 skin cancers were identified: 4,192 DFSP, 6,412 MFH, 10,543 KS, and 4,222 SC. For patients with a history of non-CLL NHL, SMRs for death due to any cause were 1.45 (95% confidence interval [CI], 1.03-2.04; p = 0.04) for MFH, 2.90 (95% CI, 2.50-3.36; p < 0.001) for KS, and 3.25 (95% CI, 1.84-5.75; p < 0.001) for SC and SMRs for death due to skin cancer were 0.55 (95% CI, 0.23-1.31; p = 0.18) for MFH, 2.93 (95% CI, 2.49-3.43; p < 0.001) for KS, and 4.07 (95% CI, 1.28-12.94; p < 0.001) for SC.

CONCLUSION

Among patients with KS and SC, patients with a history of non-CLL NHL have a greater risk of overall and cause-specific death than expected.

Evaluation of prognostic factors in localized high-grade undifferentiated pleomorphic sarcoma: report of a multi-institutional experience of Anatolian Society of Medical Oncology

Most data on prognostic factors for patients with high-grade undifferentiated pleomorphic sarcoma (HGUPS) is obtained from analyses of soft tissue sarcomas. The purpose of this study was to evaluate the clinicopathologic features and their impact on outcomes specifically in patients diagnosed with HGUPS. In this multicenter trial, we retrospectively analyzed 112 patients who were diagnosed and treated at 12 different institutions in Turkey. We collected data concerning the patients, tumor characteristics, and treatment modalities. There were 69 males (61.6 %) and 43 females (38.4 %). Median age was 56 years (19-90). The most common anatomic site of tumor origin was the upper extremity. Pleomorphic variant was the predominant histological subtype. Median tumor size was 8.2 cm (0.6-30 cm). Tumors were mainly deeply seated (57.1 %). Fifty-seven patients (50.9 %) were stage II and the remainder were stage III at the time of diagnosis. Median follow-up was 30 months (2-160). The primary site of distant metastasis was the lung (73.5 %) and the second most common site was the liver (11.7 %). The 5-year overall survival, distant metastasis-free survival, and local recurrence-free survival rates were 56.3, 53.4, and 67.2 %, respectively. Multivariate analysis showed that Eastern Cooperative Oncology Group (ECOG) performance score of II (p = 0.033), deep tumor location (p = 0.000), and development of distant metastasis (p = 0.004) were negatively correlated with overall survival, and perioperative radiotherapy and negative microscopic margins were significant factors for local control rates (p = 0.000 for each). Deep tumor location (p = 0.003) was the only adverse factor related to distant metastasis-free survival. Deep tumor location, ECOG performance score of II, and development of distant metastasis carry a poor prognostic implication on overall survival. These will aid clinicians in predicting survival and treatment decision.

Global protein-expression profiling for reclassification of malignant fibrous histiocytoma

According to the newest World Health Organization (WHO) classification for soft tissue tumors in 2013, malignant fibrous histiocytoma (MFH) has been gone. Most sarcomas called MFH were reclassified to be high-grade pleomorphic forms of leiomyosarcoma, liposarcoma, rhabdomyosarcoma, and other sarcomas by recent molecular technologies. However, about 10% to 15% of sarcomas called MFH before, still cannot be given a precise classification, and these are now called undifferentiated pleomorphic sarcoma or are still called MFH. Further molecular approaches including proteomic approaches are imperative to classify these unclassified sarcomas for improving clinical outcomes of the patients with soft tissue sarcomas. This article is part of a Special Issue entitled: Medical Proteomics.

Increased metastasis of malignant fibrous histiocytoma in patients with chronic lymphocytic leukemia and non-hodgkin lymphoma

OBJECTIVE

To further understand the characteristics and behavior of malignant fibrous histiocytoma (MFH) in the clinical setting of chronic lymphocytic leukemia (CLL) or non-Hodgkin lymphoma (NHL).

PATIENTS AND METHODS

The patient database of MHF diagnosed at our institution from January 1, 1976, to December 31, 2008, was reviewed. For each MFH case with prior NHL or CLL, 3 matched controls from the same cohort without prior CLL or NHL were randomly selected. A retrospective chart review collected patient data, including sex; age; pathologic confirmation of MFH; tumor grade, size, and location; time since MFH diagnosis; history of chemotherapy or irradiation; treatment of MFH; recurrence; metastasis; and death. The Kaplan-Meier method was used to estimate overall survival, survival free of recurrence, and survival free of metastasis. Cox proportional hazards models were fit to evaluate associations between case status and outcomes.

RESULTS

Fifteen MFH cases with prior NHL or CLL were identified. Cases had frequent bone (n=7 [47%]) and cutaneous (n=5 [33%]) involvement. Five cases (33%) had previous irradiation, 6 (40%) had metastases, and 4 (27%) had recurrence. Overall survival and survival free of recurrence were not significantly different between the cases and controls (5-year overall survival, 49.9% and 58.7%; 12-month survival free of recurrence, 79.4% and 90.3%). However, cases were significantly more likely than controls to have metastasis (hazard ratio, 3.79; 95% confidence interval, 1.22-11.79; P=.02). In addition, survival free of metastasis at 12 months was 65.2% and 90.7%, respectively.

CONCLUSION

In the presence of CLL or NHL, MFH seems to behave more aggressively, suggested by the increased likelihood of metastases compared with controls without prior CLL or NHL. However, overall survival does not appear to be worse in cases of MFH and CLL or NHL than in MFH alone.

Myxofibrosarcoma arising in the maxillary sinus: a case report with a review of the ultrastructural findings and differential diagnoses

This is a case report of a patient presenting with a destructive lesion with histologic features of a low grade malignancy in a predominantly myxoid matrix. Various low grade myxoid malignancies were considered in the differential diagnosis of which an overview is presented. A literature review of the ultrastructural findings and possible histogenesis is discussed along with the diagnostic criteria and recent change in the terminology regarding the malignancies previously diagnosed as myxoid malignant fibrous histiocytomas. A final diagnosis of a myxofibrosarcoma was only possible after assessing the immuno-histochemical profile, results of histochemical stains and ultrastructural features of this lesion.

Myxoid malignant fibrous histiocytoma with multiple primary sites

Malignant fibrous histiocytoma (MFH) is one of the most common types of soft tissue sarcomas in adults. The most common location of MFH are the extremities and the trunk, with the most common site for distant metastases being the lung. We describe a case with multiple synchronous sites of myxoid MFH but no lung metastases and presence of abnormalities of 19p13.

Digital metastases of giant cell rich malignant fibrous histiocytoma

Background. Metastatic spread of soft tissue sarcomas to the digits is extremely rare and metastasis of MFH to the fingers and toes has not been documented.Purpose. We present two case reports of metastatic spread from a giant cell rich malignant fibrous histiocytoma to the digits and discuss their management.

Malignant fibrous histiocytoma of rectum: Report of a case

Malignant fibrous histiocytoma (MFH) is the most common soft tissue sarcoma of adults, mostly distributed in the thigh, buttock and groin (46%) and presents rarely in the gastrointestinal tract, classified as gastrointestinal stromal tumors (GIST). MFH is regarded as a diagnosis of exclusion, essentially synonymous with an undifferentiated pleomorphic sarcoma. The recent report presents an 80-year-old man with clinical manifestations of rectal bleeding and final diagnosis of MFH of rectum. It seems that radical resection and adjuvant radiation is important in the management strategy of a patient with such a rare rectal tumor.

Primary intra-abdominal malignant fibrous histiocytoma: a highly aggressive tumor

BACKGROUND AND PURPOSE

Malignant fibrous histiocytoma (MFH) is the most common soft-tissue sarcoma of late adult life occurring predominantly in the extremities. Primary intra-abdominal MFH is a very rare occurrence. The aim of this study is to describe a very rare case of an intra-abdominal MFH with a highly aggressive clinical course.

METHODS

A 67-year-old male was referred to our department with a 2-week history of dull lower abdominal pain and a gradually enlarging right lower abdominal mass, which he first noticed 2 months prior to admission. Computed tomography (CT) scan demonstrated a mass in the right iliac fossa.

RESULTS

On exploratory laparotomy, a tumor was found in the right iliac fossa attached to the parietal lateral peritoneum without any evidence of invasion into the adjacent structures. Complete excision of the tumor with clear margins was performed. Histological and immunohistochemical examinations showed a MFH. One month after surgery, while on adjuvant chemotherapy, the patient was readmitted with dyspnea and a slightly palpable mass in the area of the previous radical resection. CT scan revealed local tumor recurrence along with multiple pulmonary metastatic deposits. Unfortunately, despite treatment, the patient died of progressive disease 5 weeks later.

CONCLUSIONS

Primary intra-abdominal MFH is a very rare but aggressive malignancy with a high tendency of local recurrence and metastatic spread. Early detection and complete surgical excision with clear margins is the treatment of choice. In some cases, however, the tumor can exhibit a highly aggressive clinical course despite radical surgery and adjuvant therapy.

Thymoma with coexisting undifferentiated pleomorphic sarcoma: a case report

We report here a case of thymoma simultaneously associated with undifferentiated pleomorphic sarcoma. A 45-year-old male presented with axillary lump. Radiographic studies showed a mediastinal mass. On fine needle aspiration cytology and histopathological examination, a diagnosis of thymoma with coexisting undifferentiated pleomorphic sarcoma was made. Although thymomas are associated with many extrathymic malignancies, it's association with undifferentiated pleomorphic sarcoma is rare. This case is being reported on to reinforce that clinicians should bear in mind the possibility of extrathymic malignancies in patients with thymomas.

Histiocytic sarcomas in flat-coated retrievers: a summary of 37 cases (November 1998-March 2005)

Thirty-seven cases of histiocytic-like sarcomas (HLSs) in flat-coated retriever dogs were evaluated retrospectively. This tumour accounted for 36% of the malignant tumours seen in this breed during the study period. The median age at presentation was 8.2 years. Thirty-four dogs presented with a swelling or mass in a muscle group or surrounding a joint. The remaining three presented for rib (1), cutaneous (1) or primary splenic origin (1). A high rate of metastasis to local lymph nodes (45%), thorax (20%) and abdominal organs (20% confirmed) was seen. Overall metastastic rate by the time of death was 70%. The median survival for all dogs was 123 days. The most significant prognostic indicator was presence of distant metastasis at the time of diagnosis with median survival of 68 or 200 days, with or without metastasis, respectively. Chemotherapy and radiation therapy significantly improved survival. Dogs given chemotherapy survived a median of 185 versus 34 days for dogs that were not (P = 0.0008). Dogs treated with radiation survived a median of 182 versus 60 days for those that were not (P = 0.0282). Dogs receiving only palliative therapy survived a median of 17 versus 167 days in dogs receiving any kind of radiation, chemotherapy, surgery or combinations. A set protocol of radiation and CCNU (RTCCNU) induced minimal toxicity and provided a median survival of 208 versus 68 days for all other dogs. While this tumour carries a poor long-term prognosis in flat-coated retrievers, it is reasonable to treat these dogs for palliation of signs and extension of life.

Telomere-maintenance mechanisms in soft-tissue malignant fibrous histiocytomas

BACKGROUND

Sarcomas are distinct from carcinomas in that a substantial portion of them use the alternative lengthening of telomeres (ALT) mechanism to maintain their telomeres. The present study clarifies the prevalence of the ALT mechanism and examines the prognostic importance of telomere factors in soft-tissue malignant fibrous histiocytomas.

METHODS

We investigated a series of forty-three soft-tissue malignant fibrous histiocytoma samples from forty-three patients with regard to telomere length, telomerase activity, and human telomerase reverse transcriptase (hTERT) mRNA expression. Tumor samples were obtained from surgical specimens and were stored at -80 degrees C until use. Univariate analysis of the tumor samples from patients for whom data were available on age, sex, histological grade, tumor size, surgical margin, recurrence, and telomere factors was performed with use of the log-rank test. Multivariate analysis with only significant variables was then performed.

RESULTS

Telomerase activity was detectable in 79.1% of the tumor samples, hTERT expression was demonstrated in 90.7% of the tumor samples, and evidence of engagement of the ALT mechanism of telomere length maintenance was observed in 32.6% of the tumor samples. Among the variables tested, ALT-positive status emerged as the only independent prognostic factor for death of the patient (hazard ratio, 0.275; 95% confidence interval, 0.104 to 0.724; p=0.0089). There were no significant differences in survival rates between patients with ALT-positive, telomerase-positive tumors and those with ALT-positive, telomerase-negative tumors (p=0.301) or between patients with ALT-positive tumors that showed above-average telomerase activity and those with ALT-positive tumors that showed below-average telomerase activity (p=0.900). Therefore, telomerase activity does not affect the prognosis in patients with ALT-positive malignant fibrous histiocytoma. High telomerase expression is associated with a poor prognosis in patients with ALT-negative malignant fibrous histiocytoma (p=0.0027).

CONCLUSIONS

More detailed analysis will be needed to identify the most valuable prognostic factor in patients with malignant fibrous histiocytoma, and a more thorough understanding of telomere biology may give an indication of telomere-targeting therapy in the future.

Malignant Fibrous Histiocytoma, Aggressive Fibromatosis and Benign Fibrous Tumors Express mRNA for the Metalloproteinase Inducer EMMPRIN and the Metalloproteinases MMP-2 and MT1-MMP

PURPOSE

Extracellular matrix metalloproteinase inducer (EMMPRIN) has been shown to stimulate fibroblasts to production of matrix metalloproteinases (MMPs). MMPs comprise a family of proteolytic enzymes implicated in the degradation of extracellular matrix which has been proposed to be one of the essential steps in tumor invasion and metastases. In the present study we investigated the expression and location of mRNAs for EMMPRIN, matrix metalloproteinase-2 (MMP-2), and membrane-type 1 matrix metalloproteinase (MT1-MMP) in mesenchymal tumors with different tendencies to recur or metastasize.

SUBJECTS

Eight malignant fibrous histiocytomas (MFH), seven aggressive fibromatosis (AF), and six benign fibrous tumors (BF).

METHOD

The mRNA-expression of EMMPRIN, MMP-2 and MT1-MMP were studied using mRNA in situ hybridization technique.

RESULTS

The mRNA-expression of EMMPRIN, MMP-2 and MT1-MMP respectively were found at varying frequency and level in all tumor types. The mRNAs corresponding to EMMPRIN and MMP-2 were seen in neoplastic cells as well as in endothelial cells both inside and outside the tumor pseudo-capsule, whereas MT1-MMP was seen only within the tumors. The estimated mRNA levels of EMMPRIN and MMP-2 covariated significantly. Overall, the highest expression was found in the MFH tumors and the lowest levels in the BF tumors.

DISCUSSION

These findings suggest that the MMP-inducer EMMPRIN and the extracellular matrix degrading system involving the metalloproteinases MMP-2 and MT1-MMP is frequently activated in mesenchymal tumors. The covariation between EMMPRIN and MMP-2 support previous findings that EMMPRIN may be an inducer of MMP-2. The high levels of MMP-2 mRNA in MFH indicate a relationship between the proteolytic activity of MMP-2 and the tumor aggressiveness.

Sarcoma

Sarcomas comprise a heterogeneous group of mesenchymal neoplasms. They can be grouped into 2 general categories, soft tissue sarcoma and primary bone sarcoma, which have different staging and treatment approaches. This review includes a discussion of both soft tissue sarcomas (malignant fibrous histiocytoma, liposarcoma, leiomyosarcoma, synovial sarcoma, dermatofibrosarcoma protuberans, angiosarcoma, Kaposi sarcoma, gastrointestinal stromal tumor, aggressive fibromatosis or desmoid tumor, rhabdomyosarcoma, and primary alveolar soft-part sarcoma) and primary bone sarcomas (osteosarcoma, Ewing sarcoma, giant cell tumor, and chondrosarcoma). The 3 most important prognostic variables are grade, size, and location of the primary tumor. The approach to a patient with a sarcoma begins with a biopsy that obtains adequate tissue for diagnosis without interfering with subsequent optimal definitive surgery. Subsequent treatment depends on the specific type of sarcoma. Because sarcomas are relatively uncommon yet comprise a wide variety of different entities, evaluation by oncology teams who have expertise in the field is recommended. Treatment and follow-up guidelines have been published by the National Comprehensive Cancer Network (www.nccn.org).

Superficial soft-tissue masses of the extremities

Superficial soft-tissue masses are among the most common indications for imaging of the extremities. A broad array of benign and malignant processes may be manifested in palpable cutaneous or subcutaneous masses or nodules. Most such lesions are treated with surgical excision, but some may be conservatively managed. The lesions can be differentiated according to their location in one or more skin layers (epidermis, dermis, and subcutis), their histologic composition, and the associated anatomic abnormality or disease process. Because the imaging characteristics of many benign soft-tissue lesions overlap with those of malignant ones, knowledge of the patient's clinical history (including any laboratory test results) and direct visual examination of the lesion often are important for differentiation. Histologic analysis may be necessary to achieve a definitive diagnosis.

Malignant fibrous histiocytoma of the eyelid: differential diagnosis and management

PURPOSE

Malignant fibrous histiocytoma (MFH) is a pleomorphic soft tissue sarcoma that occurs rarely in the periocular region. The purpose of this study was to present a case series of periocular MFH and to discuss the differential diagnosis and management.

METHODS

This is a retrospective case review of patients diagnosed with periocular MFH from tertiary hospitals and private practices.

RESULTS

Four patients, two women and two men with periocular MFH, had a mean age of 81 years (range, 72 to 85 years). All tumors were <5 cm in diameter and of storiform pleomorphic histologic subtype. One was located deep and 3 presented superficially. The initial diagnoses were sarcomatoid carcinoma, atypical fibroxanthoma, and leiomyosarcoma that were subsequently reclassified as MFH. One patient had a frozen section, 1 had fast track paraffin section margin control, and 2 had no frozen section margins at the initial excisions. Histology showed 2 negative margins, 1 close margin, and 1 positive margin that were cleared with wide local excision. Local recurrence occurred in 3 cases, and of these, 1 required orbital exenteration. Adjuvant radiotherapy was given to 3 patients. One had regional node metastases. There were no distant metastases or tumor-related deaths. Mean follow-up period was 36 +/- 35 months (median, 30; range, 1 to 84 months).

CONCLUSIONS

This study highlights the difficulties in the clinicopathologic diagnosis of periocular MFH and in particular the distinction of more superficial tumors from atypical fibroxanthoma. The mainstay of treatment is complete surgical excision with wide margins, and consideration should be given to histologic margin control in addition to adjuvant radiotherapy.

Characterization of sarcomas by means of gene expression

Sarcomas represent a heterogeneous group of diseases of a variety of recognized histologic types. Among these subtypes is malignant fibrous histiocytoma (MFH), a diagnosis no longer recognized as a specific diagnosis at some institutions. In this study, gene expression in 38 histologically well-defined sarcoma samples, 17 MFH samples, 12 samples of sarcomas classified simply as high-grade sarcoma (NOS, standing for "not otherwise specified"), and 26 other mesenchymal tumors was determined at Gene Logic Inc (Gaithersburg, MD), with the use of Affymetrix GeneChip U_133 arrays containing approximately 40,000 known genes and expressed sequence tags (ESTs). Gene-expression analysis was performed with the use of the Gene Logic Gene Express(R) Software System. Differences in gene expression were quantified as the fold change in gene expression between the various sets of well-defined sarcomas. A set of genes was then identified that could be used to distinguish the well-defined sets of 11 liposarcomas, 9 leiomyosarcomas, 4 synovial sarcomas, 8 schwannomas, and 12 cases of aggressive fibromatosis through the use of Eisen clustering. Eisen clustering was then repeated with the same set of gene fragments with the sample set of 38 histologically well-defined sarcomas, the 17 sarcomas classified as MFH, 12 sarcomas classified as high-grade sarcoma (NOS), and 26 other mesenchymal tumors. Under these conditions, each of the samples of well-defined sarcoma formed distinct clusters that contained some of the MFH and NOS samples. In addition, distinct clusters were observed that contained only MFH and NOS samples. We conclude that gene-expression patterns may be useful in helping further classify subtypes of sarcomas.

Time dependence of prognostic factors for patients with soft tissue sarcoma: a Scandinavian Sarcoma Group Study of 338 malignant fibrous histiocytomas

BACKGROUND

Prognostic factors for metastasis in soft tissue sarcoma govern decisions regarding adjuvant treatment. However, the significance of initial tumor-related prognostic factors over time is largely unknown.

METHODS

The current study included 338 patients with malignant fibrous histiocytoma (MFH) of the extremities or the trunk wall whose tumors were reviewed by the Scandinavian Sarcoma Pathology Review Group. Of these 338 patients, 329 (97%) had high-grade tumors. The median follow-up period was 7 years. Metastases occurred in 110 of 338 of patients after a median follow-up period of 14 months, with roughly one-third (32 of 110) occurring after 2 years. The authors investigated the prognostic significance of tumor size, tumor depth, histologic grade, microscopic tumor necrosis, vascular invasion, mitotic rate, and local tumor recurrence at various time intervals using metastases as an endpoint.

RESULTS

On univariate analysis, all investigated factors were found to be correlated with metastases for the entire follow-up period and also for the first 2 years of follow-up; beyond this time point, only size, tumor depth, and local recurrence were significant. On multivariate analysis, necrosis and local tumor recurrence were significant for the entire follow-up duration and also for the first 2 years of follow-up, whereas only tumor depth and local recurrence were significant beyond 2 years of follow-up. For all initial factors, the annual metastasis risks in the high-risk and low-risk groups converged to < 0.1 after 2 years and to near 0 after 5 years.

CONCLUSIONS

Prognostic factors for metastasis in MFH were time dependent. The predictive value of the initial prognostic factors was limited to the first 2 years of follow-up. The lack of observed prognostic value beyond 2 years of follow-up probably was attributable to heterogeneity within risk categories as a result of measurement errors and unknown biologic variations.

Gain of 17q in malignant fibrous histiocytoma is associated with a longer disease-free survival and a low risk of developing distant metastasis

In this study, a panel of 39 primary malignant fibrous histiocytomas (MFH) of high malignancy grade were characterised for chromosomal alterations. The results were then evaluated in relation to the survival and the occurrence of recurrent disease during follow-up for an average period of 63 months. Chromosomal alterations detected by comparative genomic hybridisation (CGH) were recorded in 37 of the 39 cases analysed. The most frequent CGH abnormalities were gains of 17p, 20q, 16p, 17q, 1p31, 7q21, and 9cen-q22, and losses of 9p21-pter and 13q21-22. However, the patterns of CGH imbalances did not allow the identification of a single common event, suggesting that the key initiating event(s) is not a numerical imbalance. Patients with tumours harbouring a gain of 17q showed significantly longer overall and disease-free survival (P=0.001 and 0.008) as well as lower frequency of metastasis (P=0.018) during follow-up. Taken together, the findings suggest that the clinical outcome of MFH is associated with the genetic profiles of the primary tumours. Importantly, a subgroup of MFHs characterised by a low risk of developing metastasis and local recurrence is recognised based on their frequent gains of 17q by CGH.

Pathologic and molecular aspects of soft tissue sarcomas

This article retains the conventional approach to the classification of soft tissue sarcomas, dividing them into several major histogenetic categories based on their overall microscopic appearance, tissue differentiation pattern, and biologic potential. The author advocates a multimodal approach, in which four distinctive data sets--clinical, radiographic, microscopic, and, in some cases, molecular--are considered to establish the diagnosis and treatment plan. Such step-wise analysis is more likely to lead to consistency and accuracy as compared with an intuitive approach based on fragmentary data. The author describes individual lesions of soft tissue as clinicopathologic entities and believes that they can be more accurately diagnosed and appropriately treated with the help of data generated by a multidisciplinary team. In addition, this article emphasizes the need to use emerging molecular techniques that can provide important clues for both diagnosis and prognosis.

Most malignant fibrous histiocytomas developed in the retroperitoneum are dedifferentiated liposarcomas: a review of 25 cases initially diagnosed as malignant fibrous histiocytoma

Forty-four samples from 25 cases of retroperitoneal sarcoma initially diagnosed as malignant fibrous histiocytoma were histologically reviewed. Immunohistochemistry for mdm2 and cdk4 was performed on 20 cases. Comparative genomic hybridization was performed on 18 samples from 13 patients. Seventeen cases were reclassified as dedifferentiated liposarcoma. Twenty-one of 32 samples from these patients showed areas of well-differentiated liposarcoma, allowing the diagnosis of dedifferentiated liposarcoma. Immunohistochemistry performed in 15 of these cases showed positivity for mdm2 and cdk4. Comparative genomic hybridization analysis performed on 15 samples from 11 of these patients showed an amplification of the 12q13-15 region. Eight cases were reclassified as poorly differentiated sarcoma. Twelve samples from these patients showed no area of well-differentiated liposarcoma. Immunohistochemistry showed positivity for mdm2 and cdk4 in one of six of these patients and showed positivity for CD34 in another one. Comparative genomic hybridization analysis performed on three samples from two of these patients showed no amplification of the 12q13-15 region but showed complex profiles. This study shows that most so-called malignant fibrous histiocytomas developed in the retroperitoneum are dedifferentiated liposarcoma and that a poorly differentiated sarcoma in this area should prompt extensive sampling to demonstrate a well-differentiated liposarcoma component, immunohistochemistry for mdm2 and cdk4, and if possible, a cytogenetic or a molecular biology analysis.

Clinicopathologic re-evaluation of 100 malignant fibrous histiocytomas: prognostic relevance of subclassification

PURPOSE

Malignant fibrous histiocytoma (MFH) has been regarded as the most common soft tissue sarcoma (STS) in adults. Yet its true nature and the validity of this diagnostic concept have increasingly been questioned. Available data suggest that most patients with MFH can be subclassified into specific STS types, but the clinical relevance of such categorization has been argued. In a retrospective study, we reclassified 100 tumors of the extremity and trunk wall primarily diagnosed as MFH and analyzed the outcome.

PATIENTS AND METHODS

Patients were adults (median age, 70 years; range, 32 to 94 years). The median tumor size was 8 cm (range, 1 to 30 cm), and the thigh was the most common tumor location (n = 31). Median follow-up was 8 years (range, 3 to 16 years). The overall 5-year metastasis-free survival rate was 0.64. The tumors were reanalyzed histologically, immunohistochemically, and, where available, ultrastructurally, and were classified according to strict diagnostic criteria. Patients were staged according to the American Joint Committee on Cancer system, and prognoses were compared among different groups of the reclassified diagnoses, paying special attention to myogenic tumors.

RESULTS

In 84 of 100 tumors, a specific line of differentiation was either proved or strongly suggested. The most common diagnoses were myxofibrosarcoma (n = 22) and leiomyosarcoma (n = 20). Overall, 30 tumors could be grouped as some form of myogenic sarcoma. These tumors had a worse prognosis, even within the same American Joint Committee on Cancer stage, and a shorter time to metastasis than nonmyogenic tumors.

CONCLUSION

This retrospective study confirms that most so-called MFH can be subclassified by defined criteria; it provides evidence that such classification is clinically important. Specifically, pleomorphic STS showing myogenic differentiation are significantly more aggressive, a finding that allows planning future therapeutic trials.

Immunoexpression of ultraviolet photoproducts and p53 mutation analysis in atypical fibroxanthoma and superficial malignant fibrous histiocytoma

p53 mutation is one of the major results of ultraviolet (UV) radiation. UV photoproducts of cyclobutane pyrimidine dimers (CPDs) and pyrimidine-pyrimidone (6-4) photoproducts (64PPs) also play an important role in skin cancer development. Atypical fibroxanthoma (AFX), which mimics malignant fibrous histiocytoma (MFH) histologically, occurs in the sun-exposed skin of the elderly, and therefore, an association with UV has long been suspected. Eighteen fibrohistiocytic skin lesions comprising AFX (n = 7), storiform-pleomorphic type MFH centered in the subcutis (superficial MFH; S-MFH; n = 4) and benign fibrous histiocytoma (BFH; n = 7) were used for immunohistochemical and molecular analysis. Eight cases of deep MFH (D-MFH) were also analyzed for UV photoproduct expression for the purposes of comparison. Immunohistochemically, the CPD scores of AFX (3.6 +/- 0.4) were significantly higher than those of S-MFH (1.3 +/- 0.8), D-MFH (0.8 +/- 0.5), or BHF (1.4 +/- 0.7); however, the 64PP scores were extremely low in all these tumors (AFX, 0.1 +/- 0.1; S-MFH, 0.0 +/- 0.0; D-MFH, 0.0 +/- 0.0; and BHF, 0.0 +/- 0.0). AFX, S-MFH, and BFH showed immunoexpression for p53 (2/7, 2/4, and 0/7), respectively. p53 mutations were detected in AFX (4/6; 67%) and S-MFH (1/4; 25%), but not in BFH (0/5; 0%) using polymerase chain reaction-single-strand conformation polymorphism, and all of the mutations in AFX were either C-T transitions or at dipyrimidine sites. In conclusion, AFX and S-MFH are both similar fibrohistocytic lesions; however, AFX has high immunoreactivity for CPDs compared with S-MFH, D-MFH, or BFH. These data suggest that CPDs may play an important role in the pathogenesis of AFX.

Malignant fibrous histiocytoma: an institutional review

BACKGROUND

A thorough understanding of malignant fibrous histiocytoma (MFH), the most common subtype of soft tissue sarcoma, will lead to improved histologic-specific protocols.

METHODS

126 patients with histologically confirmed MFH were analyzed. The median follow-up was 42 months (range 1-233 months).

RESULTS

Overall survival was 58% at 5 years and 38% at 10 years. Grade significantly influenced prognosis, with 10-year survival of 90%, 60%, and 20% for low, intermediate, and high grade tumors, respectively (p = 0.0007). Distant metastases at initial presentation (p = 0.0002) and size of the primary tumor (p = 0.0007) influenced outcome. Neither anatomic site nor depth of the primary tumor were significant prognostic factors. Positive microscopic margins were associated with a decreased disease-free survival (p = 0.006).

CONCLUSIONS

Tumor grade, size, and distant metastases at initial presentation remain the most important prognostic factors for MFH. Resection with negative microscopic margins decreased the incidence of local recurrence.

An unusual long-term complication of burn injury: malignant fibrous histiocytoma developed in chronic burn scar

Development of malignant tumors in chronic burn wounds is a well-known complication. These tumors are almost always squamous cell carcinomas, although other types of malignancies such as basal cell carcinoma, malignant melanoma and sarcomas can be seen rarely. There are only three previously reported cases of malignant fibrous histiocytoma developed in chronic burn scar in the literature. Two cases with malignant fibrous histiocytoma developed in chronic, badly treated burn wounds are presented. One of the tumors was multifocal and overexpression of the p53 gene was present. Both tumors were excised widely and skin grafted. Regional lymph node dissection was performed in one case. One of the patients died due to tumor recurrence and lymphatic metastases. These cases represent a very uncommon complication of burn injury and indicate the importance of the appropriate primary treatment of the burn wound.

Retroperitoneal malignant fibrous histiocytoma

Authors review the case history and follow-up of a rare malignant fibrous histiocytoma patient, based on the relevant literary data. The tumour filled the retroperitoneum on the right side, in front of the right kidney. Intravenous urography and computer tomography revealed a 10 x 15 cm sized mass, suspect of being a kidney tumour. Upon surgery, the tumour was found to be a retroperitoneal malignant fibrous histiocytoma. In connection with the case, a brief review is given of the storiform type of malignant fibrous histiocytoma, regarding its aetiological, clinical and pathological aspects, the difficulties in diagnosis, as well as the therapeutic possibilities. Authors regard their case worthy of publication because of the retroperitoneal location and significant size of the tumour, and because of the unproven diagnosis prior to surgery. Even after 4 years the patient is symptom- and complaint-free, and CT has revealed no metastases.

Malignant fibrous histiocytoma developing in a burn scar

Malignant fibrous histiocytoma (MFH) which is usually originated from muscles and deep fascia and rarely from the subcutaneous tissue is the most common soft tissue sarcoma; and it frequently invades the extremities. Occurrence of this tumor on a burn scar of scalp is a very rare entity. In the literature, there were only four reported malign fibrous histiocytoma cases that originated from a burn scar but none of them was at the scalp region. A female patient complaining about a painful mass at the scalp region was admitted to our clinic twenty years after burning with hot water when she was 3 years old. Pathological and clinical features of this rapidly growing malignant fibrous histiocytoma were similar with the other cases reported before. After the diagnosis was clear as a pleomorphic storiform type of MFH, a wide tumor excision was done because of the high risk of local recurrence.

Staging and prognostic factors in soft tissue sarcoma

Significant advances have been made in the understanding of clinicopathologic prognostic factors for soft tissue sarcoma over the past decade. Foremost among these advances is an improved ability to recognize the subset of patients at high risk for recurrent disease based on clinicopathologic data available at the time of initial presentation. Progress has also helped to elucidate specific molecular factors that have independent prognostic significance. This review outlines the updated American Joint Committee on Cancer staging system for soft tissue sarcoma and summarizes the available data on traditional clinicopathologic and molecular prognostic factors.

Infiltrative subcutaneous malignant fibrous histiocytoma: a comparative study with deep malignant fibrous histiocytoma and an observation of biologic behavior

Malignant fibrous histiocytoma (MFH) is one of the most common soft tissue sarcomas of adulthood. Although it is usually intramuscular and pseudocapsulated, we have recently observed MFHs with extremely infiltrative growth margins, which are predominantly located in the subcutis. These lesions are often associated with incomplete primary surgical excision, the subsequent need for additional surgery or adjuvant therapy, and an increased risk for local recurrence. To further analyze the growth pattern and clinical implication of the subcutaneous infiltrative MFHs, we reviewed a series of 24 subcutis and 21 intramuscular MFHs of the extremities. Morphologically, we defined "infiltrative" as tumor extension along normal tissue planes for a minimum measurable distance of 2 mm from the edge of the main mass. Radiographic findings were correlated with pathologic findings. Of the 24 subcutis MFHs, 83% showed an infiltrative growth pattern, involving 5% to 90% (mean, 51%) of the evaluable margin. Fifty percent of patients with subcutaneous MFH had both an infiltrative growth pattern and positive surgical resection margin on initial resection. Only 25% noninfiltrative subcutaneous MFHs had a positive initial surgical resection margin. Of the 21 intramuscular MFHs, only 5 (24%) had an infiltrative growth pattern that involved 5% to 90% (mean, 40%) of the evaluable margin. One of the five tumors had 90% margin infiltration with multiple positive surgical resection margins. Of 16 noninfiltrative intramuscular MFHs, 3 (19%) had positive resection margins. Magnetic resonance imaging (MRI) and/or computed tomography (CT) scan correctly identified the growth pattern in 87% of subcutaneous and 88% of intramuscular MFHs. Patient follow-up evaluation showed that four (17%) patients with subcutaneous MFHs had resection-proven recurrences, 6 to 57 months after diagnosis. All four of these tumors had infiltrative growth patterns and positive margins on the original surgical resection. There were no local recurrences of the intramuscular MFHs. Two patients of 20 in the infiltrative subcutaneous MFH group and two patients of four in the well-circumscribed subcutaneous MFH group had biopsy-proven metastases, which developed within 5 years after diagnosis. Six patients had metastases in the intramuscular MFH group. A group of MFHs, predominantly subcutaneous, have an extremely infiltrative growth pattern. This growth pattern, documented by radiographic methods and/or light microscopic examination of biopsy specimens, should indicate that a wider margin on initial resection is necessary to entirely excise the lesion. The presence or absence of an infiltrative growth pattern is not predictive of the tumor's metastatic potential.

Recognition and management of high-risk cutaneous tumors

The majority of cutaneous malignancies can be treated by the military dermatologist in a clinical setting. Recognition of tumors at high risk for recurrence or metastasis is important for any dermatologist but especially list care. Providing optimal care includes knowledge about which patients should be medavacced to larger medical centers for advanced surgical and medical treatments.

Human malignant fibrous histiocytomas in vitro: growth characteristics and their association with expression of mRNA for platelet-derived growth factor, transforming growth factor-alpha and their receptors

Eight human malignant fibrous histiocytomas were examined in vitro, in order to relate their growth properties to mRNA expression for platelet-derived growth factor (PDGF), PDGF receptor (PDGF-R), transforming growth factor-alpha (TGF-alpha) and the epidermal growth factor receptor (EGF-R). Reverse transcriptase-polymerase chain reaction (RT-PCR) showed that all cell lines expressed mRNA for PDGF-R alpha and/or PDGF-R beta; six cell lines expressed mRNA for the PDGF-A chain, with one cell line coexpressing PDGF-B chain mRNA; seven cell lines expressed mRNA for TGF-alpha whereas six cell lines expressed EGF-R mRNA. Conditioned medium from three cell lines contained PDGF; none of the cell lines released TGF-alpha. Two cell lines grew without serum requirements; whereas both expressed mRNA for PDGF, PDGF-R, TGF-alpha and EGF-R, other cell lines, unable to grow without serum, showed the same combination of growth factor/growth factor receptor expression. The two cell lines able to grow without serum were also shown to be stimulated by the addition of PDGF-BB. These findings show that simultaneous expression of mRNA for a growth factor and its receptor does not necessarily imply an autocrine or paracrine loop. However, two of our cell lines fulfil the requirements of possible PDGF-related autocrine and paracrine regulation.

Flow cytometric DNA content analysis of 185 soft tissue neoplasms indicates that S-phase fraction is a prognostic factor for sarcomas. French Federation of Cancer Centers (FNCLCC) Sarcoma Group

BACKGROUND

The authors determined the flow cytometric (FCM) DNA characteristics of 53 benign tumors and 132 malignant (71 primary, 61 recurrent) soft tissue sarcomas to investigate their heterogeneity and to evaluate the prognostic values of DNA ploidy status and S-phase fraction (SPF).

METHODS

One to 11 frozen samples were collected from 185 tumors at 10 participating centers of the French Federation of Cancer Centers (FNCLCC). All FCM analyses were performed in the same laboratory. Histologic diagnoses were collegially reviewed, and grade was assessed by the pathologists of the FNCLCC Sarcoma Group. Relationships between FCM, clinical, and pathologic data were investigated using univariate and multivariate analyses for risks of mortality and metastasis.

RESULTS

All except 2 of the 53 benign lesions were DNA diploid. One schwannoma and one desmoid tumor exhibited small abnormal DNA peaks. SPF was low in all benign lesions. One-third of the sarcomas were DNA diploid, whereas two-thirds were DNA aneuploid. Relationships were found between aneuploidy and mitotic count, grade, and histologic subtype of malignant fibrous histiocytoma. DNA ploidy status did not influence the clinical outcome. Multiple sampling performed in 32 sarcomas showed both diploid and aneuploid samples in 6 tumors. Heterogeneity was related to tumor size. SPF evaluated in 85 sarcomas was related to DNA ploidy status, mitotic count, and grade. SPF > or = 4% was significantly associated with a low overall survival rate. In a multivariate analysis performed for the whole group of 132 patients, the single factors with independent prognostic value for patient mortality were disease free status after the treatment course (P < 0.0001) and SPF (P = 0.03). In the subgroup of patients who were initially free of metastases and free of tumor after the treatment course, SPF remained the only factor that significantly influenced the overall survival rate (P = 0.021).

CONCLUSIONS

Despite its high failure rate, SPF is an independent factor in the prognosis of soft tissue sarcoma and should be considered when patients with a high mortality risk need to be selected for adjuvant chemotherapy.

Atypical fibroxanthoma. An unusual variant with osteoclast-like giant cells

We report three cases of an unusual variant of atypical fibroxanthoma with numerous multinucleated osteoclast-like giant cells. Histologically, the lesions were composed of uniformly dispersed multinucleated osteoclast-like giant cells within a pleomorphic cellular proliferation with microscopic and histochemical features of atypical fibroxanthoma. Multinucleated osteoclast-like giant cells, however, stained with KP-1, a macrophage-associated antigen only. These cells are not necessarily an integral part of the tumor and may represent a reactive histiocytic component.

Prognostic factors for patients with localized primary malignant fibrous histiocytoma: a multicenter study of 216 patients with multivariate analysis

BACKGROUND

The purpose of this study was to determine the independent prognostic variables in a well documented subset of 216 patients with localized primary malignant fibrous histiocytomas (MFH).

METHODS

Between the years 1980 and 1989, 216 patients with localized, primary (International Union Against Cancer [UICC]/American Joint Committee on Cancer [AJCC] Stage I-IVA) MFH were evaluated and treated in 10 participating centers of the sarcoma group of the French Federation of Cancer Centers (FNCLCC). Clinicopathologic factors were collected retrospectively and entered into a cooperative database. Tissue slides of all cases were jointly reviewed microscopically by the pathology subcommittee. Surgical treatment was performed on all but 6 (3%) patients. One hundred ninety-five patients (90%) were free of gross disease, with complete local control at the end of the initial treatment. The adjuvant treatment was radiotherapy in 78 patients (36%), chemotherapy in 19 patients (9%), and both in 61 patients (28%).

RESULTS

The median follow-up was 3.5 years (range, 45 days to 12 years). Five-year actuarial rates of disease specific (DSS), metastasis free (MFS), and local recurrence free (LRFS) survival were 70%, 63.3%, and 62.7%, respectively. Multivariate analyses showed that the adverse prognostic factors independently associated with decreased disease specific survival were UICC/AJC Stage III + IVA (P < 0.00001; relative risk [RR], 3.27; 95% confidence interval [CI], 1.6-6.58), residual macroscopic disease following primary local therapy (P = 0.00024; RR, 3.99, CI, 2.04-7.82), deep tumor location (P = 0.0045; RR, 3.37; CI, 1.21-9.38), non-myxoid histology (P = 0.0056; RR, 9.28; CI, 1.03-83.41), and age older than 50 years (P = 0.037; RR, 2.19; CI, 1.04-4.61). Two factors were significantly related to MFS in the patients with the poorest prognosis: histopathologic Grade 3 (P < 0.0001, RR, 3.46; CI, 2.02-5.91) and tumor size greater than 8 cm in largest dimension (P = 0.0012; RR, 2.78; CI, 1.36-3.66). With regard to LRFS, patients who did not undergo radiotherapy had reduced local control (P = 0.0043; RR, 2.36; CI, 1.46-3.83).

CONCLUSIONS

Resection of all macroscopic disease was independently associated with improved disease specific survival and adjuvant radiotherapy significantly decreased the local relapse risk. Histopathologic grade was the most important prognostic factor for DSS and MFS.

Malignant fibrous histiocytoma: outcome and prognostic factors following conservation surgery and radiotherapy

PURPOSE

Malignant fibrous histiocytoma is the most common type of soft tissue sarcoma. This communication presents an analysis of outcome and prognostic factors based on a retrospective review of patients with this disease treated by conservation surgery and radiotherapy.

METHODS AND MATERIALS

From 1966 to 1991, 271 consecutive patients with malignant fibrous histiocytoma were treated with conservation surgery and radiotherapy. The outcome with local control, metastatic relapse, and survival as end points was evaluated by univariate and multivariate statistics to delineate independently significant prognostic factors.

RESULTS

Postoperative radiation at a mean dose of 62.8 Gy was used in 195 patients and preoperative radiation at a mean dose of 50 Gy was used in 76 patients. At a median follow-up of 7.3 years, 123 patients (45%) developed disease relapse at some site. Fifty-seven (21%) developed local recurrence leading to an actuarial local relapse rate of 26% at 10 years, 83 (31%) developed metastatic relapse for a 10-year actuarial metastatic rate of 33%, and the 5-, 10-, and 15-year survival rates were 68, 60, and 46%, respectively. For local control, prior local recurrence (in 53 patients) was identified as an adverse factor, yielding a 10-year recurrence rate of 42% compared to 22% for 218 patients without prior disease (p < 0.01). Also, a positive surgical margin (in 46 patients) was adverse with a 10-year local recurrence rate of 39% compared to a recurrence rate of 17% with negative margins (167) (p=0.01). Patients with pathologically undocumented resection margins (58) had a local recurrence rate similar to those with positive margins (41% at 10 years). Tumor site (extremity vs. nonextremity), location (proximal vs. distal), size (< or = 5 cm vs. > 5 cm), and histology (myxoid vs. nonmyxoid) were not significant determinants of local outcome. For metastatic relapse, the major determinants of outcome were histology (myxoid vs. nonmyxoid) and tumor size. Myxoid tumors (59 patients) had a low metastatic propensity (13% 10-year metastatic rate) compared to nonmyxoid tumors (212 patients) (40% 10-year metastatic rate) (p < 0.01). Size was an important covariate for metastases for both myxoid and nonmyxoid tumors. For nonmyxoid tumors the 10-year metastatic rates were 23 and 51% for lesions less than or greater than 5 cm. For myxoid tumors a significant metastatic rate appeared only for tumors exceeding 10 cm (10-year metastatic rates of 8% vs. 44% for tumors less than vs. greater than 10 cm). In this retrospective review we found no evidence that adjuvant chemotherapy decreased the metastatic rate. In multivariate analysis for metastatic relapse and survival, tumor histology (nonmyxoid vs. myxoid) and size (< 5 cm vs. > 5 cm) were the only independent determinants of outcome.

CONCLUSION

Malignant fibrous histiocytoma is a heterogeneous disease and its myxoid variant must be recognized as a distinct entity. Both variants are locally aggressive and require equally aggressive local therapy. Conservation surgery striving for negative margins with radiation therapy provides acceptable local control and is the treatment of choice for this disease. Patients with myxoid tumors do not require systemic therapy; patients with nonmyxoid disease exceeding 5 cm are at significant risk for metastases and the development of effective adjuvant treatment is an important research tool.