Myxofibrosarcoma (myxoid malignant fibrous histiocytoma) showing cutaneous presentation: report of two cases

Epidemiology and survival factors of appendicular myxofibrosarcoma: a SEER-retrospective study

Background

The low incidence of myxofibrosarcoma (MFS) makes high power studies difficult to perform. Demographic and prognostic factors for MFS and how they differ from all extremity soft tissue sarcomas (STS) are not well understood. The purpose of this study was to characterize a large cohort of patients with MFS and evaluate epidemiologic and survival factors when compared to all STS.

Materials and methods

We performed a retrospective review of the Surveillance, Epidemiology, and End Results (SEER) database from 2000 to 2015 to identify 1,440 patients diagnosed with MFS and 12,324 with STS. Survival curves were creased using Kaplan-Meier, and Cox regression analyses were performed to identify hazard ratios (HRs).

Results

Overall survival was greater for STS than MFS (79% vs. 67%). Patients with MFS had a higher average age at diagnosis than STS (62 vs. 56), and older age was strongly associated with decreased survivorship for MFS (HR = 7.94). A greater proportion of patients under 30 diagnosed with MFS were female when compared to STS (49.6% vs. 45.4%). The incidence of MFS and STS increased over the 15-year period, with MFS increasing at a greater rate than STS (1.25% vs. 2.59%). Survival increased for patients diagnosed after 2008 for both STS (9.4%) and MFS (13.2%).

Conclusions

There are differences between patient demographics and survival factors when comparing MFS to all STS. Monitoring changes in demographic and survival trends for rare STS subtypes like MFS is important to improve diagnostic algorithms and treatment options.

Synovial sarcoma of the popliteal fossa

Soft tissue sarcomas are heterogeneous group of neoplasms making up to 1% of all malignant tumors in the adult population. The tumor generally appears on the extremities near large joints of middle-aged patients, especially in the popliteal fossa. Our patient presented in February 2014 due to a slowly enlarging, darker-colored swelling in the left popliteal fossa. Upon physical examination, a somewhat nodular, immobile, tender subcutaneous mass was observed. There was no locoregional lymphadenopathy. Patohistological findings showed a high-grade primary malignant mesenchymal tumor, biphasic synovial sarcoma type. The patient underwent surgery with wide surgical excision, followed by radiotherapy treatment. Magnetic resonance imagining follow up after one year revealed tumor recurrence. Neurovascular bundle involvement was detected, but without adjacent bone and muscular invasion and above-the-knee partial amputation of the left leg was performed. The intervention resulted in a remission of the neoplastic process and the patient was scheduled for regular check-ups. Broad surgical resection of the tumor with negative margins was the primary treatment in this case. Mutilating operations are necessary when anatomical structures around the tumor do not allow complete reintervention.

Surgical excision margins for fibrohistiocytic tumors, including atypical fibroxanthoma and undifferentiated pleomorphic sarcoma: A probability model based on a systematic review

BACKGROUND

Mohs micrographic surgery or wide local excision is the treatment of choice for fibrohistiocytic tumors with metastatic potential, including atypical fibroxanthoma (AFX) and cutaneous undifferentiated pleomorphic sarcoma (cUPS). Since margin clearance is the strongest predictor of clinical recurrence, improved recommendations for appropriate surgical margins help delineate uniform excision margins when intraoperative margin assessment is not available.

OBJECTIVE

To determine appropriate surgical wide local excision margins for AFX and cUPS.

METHODS

Literature search (Ovid MEDLINE, Embase, Web of Science, and Cochrane Library from inception to March 2020) to detect case-level data. Estimation of margins required using a mathematical model based on extracted cases without recurrences.

RESULTS

Probabilistic modeling based on 100 cases extracted from 37 studies showed peripheral clearance margin (ie, wide local excision margin) calculated to clear 95% of all tumors was 2 cm for AFX and 3 cm for cUPS. AFX tumors 1 cm or less required a margin of 1 cm.

LIMITATIONS

Data were extracted from published cases.

CONCLUSIONS

Atypical fibroxanthoma removed with at least a 2-cm peripheral excision margin is less likely to recur. Smaller tumors 1 cm or less can be treated with a more conservative margin. Margin-control surgical techniques are recommended to ensure complete removal while minimizing surgical morbidity.

Rare, risky, recurrent: An enigmatic cutaneous polyp

Myxofibrosarcomas (MFSs) are sarcomas most commonly seen in older patients. These are tumors of deep soft tissue seen in subcutaneous tissue and deep fascia, with frequent muscle involvement. These sarcomas are notorious for recurrences and progression to a higher grade with notable metastatic potential. They are very often under-diagnosed owing to their inherent morphological variability. A case of MFS is presented as a cutaneous, exophytic, polypoidal mass because of its rarity and importance of timely diagnosis, as under-diagnosis may lead to inadequate clearance of tumor, recurrences, metastases and increased mortality.

Multiple low-grade fibromyxoid sarcoma on the upper arms with atypical histological presentation

Low-grade fibromyxoid sarcoma (LGFMS) is a rare variant of spindle cell tumor that is composed of collagen-rich and myxoid parts. We describe the case of a 61-year-old Japanese patient with multiple, recurrent LGFMS on the upper arms with atypical histological presentation. In the present case, we resected the tumor several times with a minimal surgical margin, as in Moh's microsurgery. However, this can frequently lead to local recurrence of the tumor. Our case suggested that, regarding mesenchymal tumors with potential of malignancy in the skin, an initial wide excision is indispensable for complete remission of the tumor, even for low-grade malignancy such as LGFMS.

Myxofibrosarcoma: a diagnostic pitfall

Abstract

Myxofibrosarcoma (MFS) is a variant of the group of malignant fibrous histiocytomas. It is one of the most aggressive types of soft tissue neoplasms. The clinical presentation is not pathognomonic and the histological aspects are highly heterogenous, frequently delaying the diagnosis or leading to misdiagnosis. Complementary histochemical and immunohistochemical stainings are mandatory to achieve the diagnosis of MFS. A 78-year-old male patient is presented illustrating this diagnostic pitfall. Extensive surgery followed by radiotherapy is the first choice treatment.

CD34-positive superficial myxofibrosarcoma: a potential diagnostic pitfall

BACKGROUND

Myxofibrosarcoma (MFS) arises most commonly in the proximal extremities of the elderly, where it may involve subcutaneous and dermal tissues and masquerade as benign entities in limited biopsy samples. We encountered such a case, in which positivity for CD34 and morphologic features were initially wrongly interpreted as a 'low-fat/fat-free' spindle cell/pleomorphic lipoma. Case series have not assessed prevalence of CD34 reactivity among cutaneous examples of MFS.

METHODS

We performed a systematic review of our institution's experience, selecting from among unequivocal MFS resection specimens those superficial cases in which a limited biopsy sample might prove difficult to interpret. These cases were immunostained for CD34 and tabulated for clinicopathologic characteristics.

RESULTS

After review of all MFS diagnoses over 5 years (n = 56), we identified a study group of superficial MFS for comparison to the index case (total n = 8). Of these, the index and three additional cases (4 of 8, 50%; 2 low, 2 high grade) demonstrated positive staining for CD34, with diffuse staining of spindled cells including cellular processes. Four additional cases showed no or equivocal/rare staining.

CONCLUSIONS

CD34 positivity should be recognized as prevalent among such cases and should not be inappropriately construed as inveighing against a diagnosis of MFS in favor of benign entities.

High-grade myxofibrosarcoma presenting at the spermatic cord after radiotherapy for prostate cancer

A 72-year-old man with a history of prostate cancer presented 7 years postradiotherapy with a painless, egg-sized, rapidly growing nodule on the left groin at the radiation site. He underwent left high orchiectomy under a diagnosis of groin lymph node metastasis of prostate cancer. The tumour had penetrated deep into the internal inguinal ring and was resected as proximally as possible to the internal ring with a positive surgical margin. Macroscopically, the left testis was intact in the resected specimen. Immunohistochemical staining revealed that the tumour consisted of myxofibrosarcoma (MFS) with spindle cells; and was positive for vimentin, cytokeratin (AE1/AE3), MIB-1 and CD68, and negative for α-SMA, S-100, CD34 and myogenin. Thus, the tumour was diagnosed as high-grade MFS of the spermatic cord. Postoperative CT revealed a right renal tumour and adrenal tumour. Right radial nephrectomy was performed and the patient was doing well at 10-month follow-up.

Recurrence of atypical fibroxanthoma. Diagnosis and treatment

INTRODUCTION

 The soft tissue sarcomas (SPM) accounts for only 1% of malignant tumors of the adult population. The SPM is the most frequent malignant fibrous histiocytoma (MFH) that exhibits behavior characterized by the tendency to invasion of adjacent tissue and metastatic spread early. One of its variants is the atypical fibroxanthoma (FA).

OBJECTIVE

 To describe a case of probable recurrence of AF underwent surgical treatment and presentation of a literature review.

CASE REPORT

 Patient female, 63 years, presenting with a mass in the face about four inches and a history of prior resection of the lesion in the same topography. The patient underwent surgical resection with a diagnosis of AF.

CONCLUSION

 The FA is a rare tumor histological diagnosis difficult. The correct histological diagnosis and patient follow-up are essential.

["Dangerous" cutaneous polyp. Exophytic cutaneous myxofibrosarcoma]

Malignant skin tumors are seldom polypoid lesions. Thus lesions presenting as large skin tags, as in this case, may initially not be recognized and treated as a malignancy. Often such protuberant lesions are removed by shave biopsy. Then, as in this case, the clinician is very surprised to receive the diagnosis of myxofibrosarcoma (MFS). This case shows how important it is to further investigate a common tumor, like a large skin tag, when its clinical appearance is unusual. Myxofibrosarcoma or myxoid malignant fibrous histiocytoma is one of the common, perhaps most common, sarcoma in adults. Clinical presentation as a large skin tag is extremely uncommon. The rapid growth of the polypoid sarcoma indicates the need for completely operative removal. The behavior of the MFS depends on the degree of malignancy, depending on the tumor size, depth of penetration and local control. While smaller dermal or subcutaneous localized MFS hold potentially a risk of recurrence, do larger examples with a high tumor grade and seated in the deep soft tissue posses a variable metastatic potential. Despite large variability of cell number, cellular atypia and the numbers of mitotic figures all myxofibrosarcoma have in common the multinodular structure with incomplete septa, the mucinous stroma and curvilinear fine vessels.

Malignant fibrous histiocytoma with in-transit metastasis

Malignant fibrous histiocytoma (MFH) is the most common fibroblastic tumor, but its cutaneous metastasis, especially in-transit metastasis, is extremely rare. We describe the case of a 30-year-old Japanese man with a recurrent MFH on the scalp accompanied by in-transit metastasis, which had been treated as a benign skin tumor 8 years before. The main bulk of the recurrent tumor was located in the dermis, but the metastatic tumor was mainly located in the subcutis. Generally, atypical fibroxanthoma, also known as cutaneous MFH, is rarely metastasized and presents a benign clinical course. Since there is a great difference between the prognosis of MFH and atypical fibroxanthoma, precise diagnosis of the primary tumor is essential.

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.

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.

CD10-positive myxofibrosarcomas: a pitfall in the differential diagnosis of atypical fibroxanthoma

CD10 is now commonly used to differentiate atypical fibroxanthoma (AFX) from melanoma, spindle cell and dedifferentiated variants of squamous cell carcinoma and leiomyosarcoma. However, we have encountered CD10-positive tumors that mimicked AFX but proved to be myxofibrosarcomas. The purpose of this study was to evaluate CD10 expression in a wide range of mesenchymal neoplasms that may involve the skin using tissue microarrays. Our results indicate that in addition to AFX, CD10 expression is common in myxofibrosarcomas, undifferentiated pleomorphic sarcomas, dermatofibromas and dermatofibrosarcoma protuberans. Myxofibrosarcomas commonly present in the skin and may be difficult to distinguish from AFX on small biopsies and CD10 positivity may confound the diagnostic difficulty.

Fungating soft-tissue sarcomas. Treatment implications and prognostic importance of malignant ulceration

BACKGROUND

Several variables have been reported as being prognostic with regard to the outcomes of soft-tissue sarcomas. Although the tumors are subjectively ominous, no prior study has been performed to evaluate the treatment or prognosis of fungating soft-tissue sarcomas.

METHODS

We performed a retrospective review of all soft-tissue sarcomas treated at our institution between 1989 and 2004 that had been followed for a minimum of two years or until the death of the patient. Our study group consisted of twenty-four patients with a primary high-grade fungating tumor, and our control group consisted of 146 consecutive patients with a primary high-grade non-fungating tumor. The study cohorts were compared with regard to disease presentation, treatment, and oncologic outcomes.

RESULTS

There were no significant differences in tumor size, tumor depth, or histopathologic diagnoses between the cohorts, although the patients with a fungating tumor tended to be older (mean, sixty-five years compared with fifty-five years in the control group; p = 0.004) and have shorter postoperative follow-up (mean, thirty-eight months compared with sixty-five months in the control group; p = 0.03). The proportion of patients presenting with metastases was significantly greater in the group with a fungating tumor (33% compared with 9% in the control group; p = 0.003). Significantly more patients with a fungating tumor underwent amputation (35% compared with 12% in the control group; p = 0.01), while a greater proportion of control patients received radiation therapy (68% compared with 39% in the group with a fungating tumor; p = 0.02). There was no difference in the proportions of patients receiving chemotherapy or in the local recurrence rates between the two cohorts. The Kaplan-Meier five-year overall survival estimates were 20% in the group with a fungating tumor compared with 63% (p < 0.0001) in the control group. The Kaplan-Meier five-year disease-specific survival estimates for patients presenting with localized disease was 58% in the group with a fungating tumor and 74% in the control group (p = 0.05). Multivariate analysis demonstrated that disease stage, fungation, and a tumor size of > or = 10 cm were significant independent negative prognostic factors for disease-specific survival.

CONCLUSIONS

Malignant tumor ulceration is an independent predictor of a poor prognosis for patients with a high-grade soft-tissue sarcoma. Despite the discouraging overall prognosis, aggressive multidisciplinary treatment can lead to long-term survival in an important subgroup of patients with fungating lesions.

Diagnostically Challenging Spindle Cell Lipomas: A Report of 34 “Low-Fat” and “Fat-Free” Variants

Spindle cell lipomas (SCL) classically occur as subcutaneous masses in the upper trunk/neck of older men and are composed of mature fat, CD34-positive spindled cells, ropey collagen, myxoid matrix, and blood vessels. A number of variants have been reported, including SCL with pseudoangiomatous change, composite SCL hibernoma, and composite SCL/pleomorphic lipoma. A review of over 300 consultation cases diagnosed as SCL revealed 34 cases in which fat was noted to be present in <5% of the tumor (n = 30) or absent (n = 4). These cases posed diagnostic difficulties because of the dearth of fat; we propose the terms "low-fat" and "fat-free" SCL for these variants. The tumors presented in older men (mean, 56 years; ratio of males to females, 11:1) and presented as small (mean, 2.0 cm) circumscribed dermal or subcutaneous masses of the head/neck (n = 18), back (n = 7), shoulder (n = 5), leg (n = 2), arm (n = 1), or unknown location (n = 1). In the majority, referring pathologists considered benign diagnoses, usually benign nerve sheath tumors, but in four cases low-grade sarcoma was considered. In only three cases was SCL considered. The tumors were composed of aggregates of CD34-positive, bland spindled cells arranged in characteristic parallel arrays, admixed with ropey collagen and myxoid matrix. Isolated clusters or single adipocytes were present in 30 cases; four were devoid of fat. CD34 was diffusely positive (10/11). A high index of suspicion based on clinical context and identification of other typical features of SCL are key features to the diagnosis of low-fat and fat-free SCL.