Low-grade myxofibrosarcoma presenting at the site of prior high-grade disease

Myxofibrosarcoma is one of the most common soft tissue sarcomas occurring in older adults. It can arise de novo or can be radiation induced, and the term myxofibrosarcoma was originally devised to encompass a spectrum of myxoid tumors with characteristics similar to malignant fibrous histiocytoma (MFH). Confusion exists, however, regarding the distinction between microscopic grade and characteristics of myxofibrosarcoma and MFH. Correct classification is vital to prognosis, as the degree of myxoid change is inversely related to the incidence of metastasis. We present a case of a 76-year-old man with a history of high-grade MFH of the left lower extremity, status post excision and radiation therapy, who presented 2 years later with a regional metastatic recurrence of high-grade MFH to the left groin as well as new nodules adjacent to and within his prior excision and radiation site. These new nodules were determined to represent low-grade myxofibrosarcoma. These new low-grade lesions either represent a low-grade recurrence of high-grade sarcoma or a new, radiation-induced soft tissue sarcoma occurring at the same site. Radiotherapy, however, is an unlikely cause; specific postradiation sarcoma criteria have not been fulfilled. This article discusses both the nosology and histopathological spectrum of these important soft tissue sarcomas, their aggressive and recurrent nature and their association with radiation therapy.     

Malignant fibrous histiocytoma

A 62-year-old patient presented with slow-growing blue-red tumor on his left forearm for around two years. A biopsy revealed the tumor was a rare malignant fibrous histiocytoma (MFH). The finger-like extensions of MFH in the fatty tissue are responsible not only for the high local recurrence rate, but also increase the metastatic potential and affect the prognosis. For this reason radical surgery with surgical margins of 2?C3 cm is absolutely required. After wide excision, the patient has been alive for years without evidence of local recurrence or distant metastasis.     

Atypical fibroxanthoma: DNA ploidy analysis of 14 cases with possible histogenetic implications

The histogenesis of atypical fibroxanthoma (AFX) and its relationship to malignant fibrous histiocytoma (MFH) arc a subject of controversy. Many investigators have proposed that AFX may represent a reactive process, while others contend that it is a true fibrohistiocytic neoplasm, closely related to MFH. In an attempt to determine whether biologic differences between AFX and MFH may be accounted for at the cellular DNA level, we performed ploidy analysis on 14 cases of AFX by flow cytometry and compared our results with previously reported DNA analyses of MFH. Thirteen of the 14 lesions demonstrated diploid distribution of nuclear DNA, and only 1 case had an aneuploid population. This contrasts with prior data on MFH, the vast majority of which are aneuploid. Our results suggest that, despite histologic similarities, AFX may be distinguished from MFH on the basis of DNA content. These findings may be significant in understanding the biologic behavior of AFX.     

Superficial malignant fibrous histiocytoma presenting as recurrent atypical fibroxanthoma

Atypical fibroxanthoma (AFX) and malignant fibrous histiocytoma (MFH) are neoplasms of probable fibrohistiocytic lineage. The precise relationship between AFX and MFH remains controversial. We present two cases in which a lesion was excised from the face of an elderly person and reported as AFX. Both cases recurred within 12 months and were reclassified as MFH. They were excised with slow Mohs' micrographic surgery, with adjuvant radiotherapy in one case. In the other, a further recurrence was treated with orbital exenteration and radiotherapy. We review the difficulties in differentiating between AFX and MFH and the implications for treatment.     

Immunohistochemical study of membrane type-matrix metalloproteinases (MT-MMPs) and matrix metalloproteinase-2 (MMP-2) in dermatofibroma and malignant fibrous histiocytoma

Matrix metalloproteinases (MMPs) play an important role in tumor invasion and metastasis. Enhanced expression of matrix metalloproteinase-2 (MMP-2) has been demonstrated in dermatofibroma (DF) and malignant fibrous histiocytoma (MFH). MMP-2 has been shown to be activated by membrane-type MMPs (MT-MMPs). To study the role of MT-MMP in the activation of MMP-2, skin specimens of DF (five cases) and MFH (three cases) were immunohistochemically studied using in situ zymography and the antibodies against matrix metalloproteinase-2 (MMP-2) and membrane type 1-3-MMPs (MT1-3-MMPs). Both MMP-2 activity and its expression were significantly activated in the tumor cells in DF and MFH. Anti-MT2-MMP strongly reacted with tumor cells of all cases of DF and MFH, whereas anti-MT1 or 3-MMP antibody showed a weak reaction in some cases of DF and MFH. Double immunofluorescence labeling demonstrated that the immunoreactive cells with anti-MMP-2 antibody in DF and MFH consistently reacted with anti-MT2-MMP antibody. The results suggest that the activation of MMP-2 in the benign and malignant fibrous tumors is related to the activation of MT-MMPs.     

A Case of Subcutaneous Malignant Fibrous Histiocytoma Circumscribed by Fibrous Tissue

We report a case of malignant fibrous histiocytoma (MFH) located in the subcutaneous tissue on the right axilla. We excised the tumor sufficiently beyond the clinical margin. It was pathologically diagnosed as a storiform-pleomorphic type of malignant fibrous histiocytoma almost completely circumscribed by fibrous tissue, including fascicles of fibroblasts; this is a rare histological picture. The tumor has not recurred for three years. Although MFH frequently undergoes metastasis, the circumscribed-type subcutaneous MFH characteristic of superficiality and of histologically well-defined structure seems to have a relatively more favorable prognosis after adequate radical excision.     

CD99 immunoreactivity in atypical fibroxanthoma and pleomorphic malignant fibrous histiocytoma: a useful diagnostic marker

Atypical fibroxanthoma (AFX), a benign lesion, and pleomorphic malignant fibrous histiocytoma (MFH) are thought to represent points along the same neoplastic spectrum but with different prognoses and treatments. Diagnosis based on histology and clinical parameters alone is sometimes difficult, and a reliable cost-effective immunohistochemical marker to help distinguish these lesions would be beneficial. The diagnosis of AFX or MFH was based upon published clinical and microscopic criteria. Formalin-fixed, paraffin-embedded tissues of 17 cases of AFX and 26 cases of MFH were immunostained with monoclonal antibody to CD99. For all cases, CD99 expression was scored on a four-tiered scale: negative, weak (1+), moderate (2+), or strong (3+). Two pathologists blinded to tumor diagnoses and type of immunostain evaluated each case independently. The interobserver correlation coefficient was calculated. Seventeen patients with AFX (16 males and one female; mean age = 79) and 26 patients with MFH (16 males and 10 females; mean age = 60) were included. AFX lesions were from the head and the face, mean size = 1.5 cm, and MFH lesions were from the head, the neck, the trunk, and the upper/lower extremities, mean size = 5.2 cm. The 17 cases of AFX demonstrated moderate or strong (2 to 3+) immunoreactivity with CD99, compared to nine of 26 (35%) MFH cases (chi-square = 18.38; p < 0.001; interobserver correlation coefficient = 0.83). Of these, 16 of 17 (94%) AFX cases stained diffusely with CD99, while only four of 26 (15%) MFH cases stained diffusely. Control slides were adequate. Our study demonstrated that CD99 can help distinguish AFX from MFH, in addition to other immunohistochemistry as well as clinical and histologic criteria.     

Malignant fibrous histiocytoma developing in a burn scar

A case of malignant fibrous histiocytoma (MFH) developing in a burn scar is presented. The patient was burnt at 3 years of age and 25 years later, a rapidly growing tumour developed in the burn scar. MFH was diagnosed by light and electron microscopy and by an immunoperoxidase method. This complication of a burn scar has not been previously reported.     

Malignant fibrous histiocytoma

A 74-year-old man presented with a malignant fibrous histiocytoma (MFH) on the lower leg. Wide local excision was performed and no recurrence has occurred to date. The pathological features which distinguish MFH from other sarcomas are now well denned and deserve wider recognition.     

A giant malignant fibrous histiocytoma on the scalp

Malignant fibrosis histiocytoma (MFH) is one of the most common soft tissue sarcomas of adult life. The most common sites of origin are the proximal extremities, particularly the thigh and buttock. The tumors are multilobular fleshy masses, often apparently circumscribed on gross examination. We report a case of a MFH of the head in a 57-year-old woman. Our case is clinically unusual in that the tumor rapidly grew up to 15 cm in a very short time.     

Nucleolar organizer regions in fibrohistiocytic tumors of the skin

Nucleolar organizer regions (NORs) are loops of DNA which are present within the nucleoli of cells that possess ribosomal RNA (rRNA) genes. NORs are associated with proteins which can be visualized by a simple silver staining technique. As the number of NORs appears to reflect cell and nuclear activity its determination in benign, intermediate and malignant conditions could be of help in their differential diagnosis. In this study, we investigated 35 fibrohistiocytic tumors of the skin of benign, intermediate and malignant potential from 32 patients: 15 fibrous histiocytomas (FH), 5 FH with atypia (AFH), 7 atypical fibroxanthomas (AFX), 5 dermatofibrosarcoma protuberans (DFSP) and 3 malignant FH (MFH). A one-step silver technique was used on formalin or Bouin fixed specimens. Ag-NOR counts from benign conditions (FH, AFH) significantly differed from that of their intermediate-risk (AFX, DFSP) and malignant (MFH) counterparts. Furthermore, in 2 cases (one AFX; one MFH) which twice recurred, Ag-NOR counts steadily increased with time. However, a distinction could not be achieved between AFX and MFH. Although Ag-NOR is a simple and valuable technique, it does not allow a definite distinction between malignant and intermediate processes, at least as far as fibrohistiocytic tumors of the skin are concerned.     

Malignant fibrous histiocytoma arising on chronic osteomyelitis

We present a case of a primary malignant fibrous histiocytoma of the skin (MFH) arising on chronic osteomyelitis in a 67-year-old woman. Although this condition seems to be a predisposing factor for the onset of the malignancy, MFH complicating chronic osteomyelitis is generally localized at the level of the bone tissue. In the case we report the neoplasm was primitively localized at the dermal and subcutaneous level and presented as a rapidly growing mass.     

Atypical fibroxanthoma

Atypical fibroxanthoma (AFX) is a rare neoplastic disease of the skin. Since the term was coined in the early 1960s, the disease has been viewed in many ways. For a long time AFX was regarded as a superficial variant of malignant fibrous histiocytoma (MFH). When the concept of MFH was re‐evaluated and the term “undifferentiated pleomorphic sarcoma” (UPS) introduced, the controversy about the nature of AFX increased. The following review aims at providing an understanding of the present status of diagnosis and therapy of AFX based on the historical context and current data.     

Aneuploidy in atypical fibroxanthoma: DNA content quantification of 10 cases by image analysis

It has recently been reported that atypical fibroxanthoma (AFX) is a predominantly diploid lesion in contrast to malignant fibrous hystiocytoma (MFH) which is usually aneuploid. To test this hypothesis, DNA content quantification was undertaken on Feulgen-stained cytology and tissue section preparations from 10 cases of AFX by image analysis. The large-atypical cells which characterize AFX were aneuploid in each case. Smaller spindle-shaped cells found in this lesion were diploid. The results suggest that AFX is indistinguishable from MFH by DNA content estimation and highlight an advantage of image analysis over (low cytometry.     

复发性恶性纤维组织细胞瘤

报告1例切除14年后复发的恶性纤维组织细胞瘤。患者男，62岁。14年前行右胫前恶性纤维组织细胞瘤切除术，术后恢复良好。3个月前右胫前原手术部位又出现一肿块，逐渐增大，3d前肿块表面皮肤破溃，无明显自觉症状。肿块组织病理检查：肿瘤细胞排列呈梭形或星形，可见核分裂相及核瘤巨细胞，肿瘤细胞位于黏液样基质中，间质血管丰富，出血明显。     

Benign cellular fibrous histiocytoma with erosion of the phalanx

Fibrohistiocytic tumors are characterized by the presence of fibroblast like spindle cells and histiocytes. The benign fibrous histiocytoma (dermatofibroma, BFH) as well as the malignant dermatofibrosarcoma protuberans (DFSP) and the malignant fibrous histiocytoma (MFH) belong to this group. A recurrent painful, hard 2 cm tumor on the left hallux of a 54-year-old woman led to an erosion of the underlying phalanx. The patient had suffered from ingrown toenails for more than 10 years. Histologically there was a deep penetrating fibrohistiocytic tumor that grew in a storiform pattern with interspersed foam cells. The tumor was CD34 negative and mitoses were scarce. The diagnosis was benign cellular fibrous histiocytoma (BZFH). BZFH belong to the group of BFH with a high recurrence rate especially after incomplete removal. Damage to the underlying bone has not been reported so far.     

Atypical fibroxanthoma

Atypical fibroxanthoma (AFX) is a rare neoplastic disease of the skin. Since the term was coined in the early 1960s, the disease has been viewed in many ways. For a long time AFX was regarded as a superficial variant of malignant fibrous histiocytoma (MFH). When the concept of MFH was re-evaluated and the term "undifferentiated pleomorphic sarcoma" (UPS) introduced, the controversy about the nature of AFX increased. The following review aims at providing an understanding of the present status of diagnosis and therapy of AFX based on the historical context and current data.     

Flow-cytometric DNA analysis in cutaneous fibrohistiocytic tumors

BACKGROUND: Fibrohistiocytic tumors are rare skin tumors. There are many kinds of fibrohistiocytic tumors. It is often difficult to differentiate dermatofibrosarcoma protuberans (DFSP) and malignant fibrous histiocytoma (MFH) from dermatofibroma (DF) and other benign tumors. OBJECTIVE: In this study, the possible usefulness of DNA ploidy for the differentiation was studied. METHODS: Five MFH, 9 DFSP, 3 DF, 2 lipofibromas and 2 scars were studied for DNA ploidy using a flow cytometer. RESULTS: All the 7 benign tumors showed a diploid pattern. Of 14 malignant fibrohistiocytic tumors, 8 cases (57.1%) showed an aneuploid and 6 a diploid pattern. Two of 5 MFH (40.0%) and 6 of 9 DFSP (66.7%) showed an aneuploid pattern. These results showed that fibrohistiocytic tumors with an aneuploid pattern are malignant, though those with a diploid pattern may be benign or malignant. CONCLUSION: Analysis of DNA ploidy using flow cytometry was concluded to be useful for the differentiation of malignant fibrohistiocytic tumors from benign ones.     

Immunohistochemical analysis of platelet-derived growth factor and its receptors in fibrohistiocytic tumors

Platelet-derived growth factor (PDGF) is known to stimulate the proliferation of fibroblasts, although the role of PDGF and its receptors in the development of fibrohistiocytic tumors has not been clarified. In this study, we investigated this role by immunohistochemically staining PDGF and PDGF β-receptors in paraffin-embedded dermatofibroma (DF), dermatofibrosarcoma protuberans (DFSP) and malignant fibrous histiocytoma (MFH) tissue. We also immunohistochemically investigated the relationship between PDGF β-receptors and CD34, which is a known immunohistochemical marker for DFSP. Immunohistochemical studies using anti-PDGF-AA or BB antibodies showed that PDGF-AA and BB was found in 20 to 40% of the tumor cells in DF, DFSP, and MFH. No definite relationship for each tumor type was found. The expression of PDGF β-receptors in DFSP and that of MFH tissue was significantly greater in comparison to DF and scar tissue. The expression of CD34 and PDGF β-receptors in DFSP was observed in identical areas. These findings suggest that autocrine or paracrine growth stimulation, through PDGF β-receptors, is related to the tumorous proliferation of fibrohistiocytic tumors, and the expression of PDGF β-receptors might play a role in the proliferation of CD34 positive tumor cells.