Myxoinflammatory fibroblastic sarcoma

Myxoinflammatory fibroblastic sarcoma: spectrum of disease and imaging presentation

OBJECTIVES

To describe the imaging findings of a series of myxoinflammatory fibroblastic sarcomas (MFSs) from our institution, including a case of dedifferentiated MFS and two cases with areas of high-grade tumor, in addition to typical cases of low-grade tumor. To correlate the imaging findings with the pathologic features of these tumors.

SUBJECTS AND METHODS

IRB approval was obtained. Retrospective search of the pathology database at our institution from 2000 to 2015 identified seven cases of MFS with available imaging. Imaging, pathology, and clinical data were reviewed.

RESULTS

Unlike the majority of well-differentiated tumors in our series (four cases), one tumor showed dedifferentiation and two cases had areas of high-grade tumor. The dedifferentiated tumor showed peripheral post-contrast enhancement. One case with a substantial high-grade component showed osseous destruction and peripheral enhancement in the high-grade area, while the low-grade component enhanced diffusely. The second case had a small high-grade area and showed diffuse enhancement. All three of these cases had non-acral locations and lacked association with a tendon. The four cases of low-grade MFS demonstrated diffuse enhancement, were located in the distal extremities, and were associated with a tendon.

CONCLUSION

The imaging findings of dedifferentiated and high-grade MFS differ from the more typical low-grade tumors in that they have nonenhancing areas, a non-acral location, lack association with a tendon, and may involve bone. The radiologist should be aware that MFS represents a spectrum that includes low-grade tumors, tumors with high-grade areas, and tumors with dedifferentiation and that this spectrum presents with differing imaging features.

Myxoinflammatory fibroblastic sarcoma of the scalp: aggressive behavior at a rare, nonextremity site

Myxoinflammatory fibroblastic sarcoma (MIFS) is a rare low-grade malignant soft tissue neoplasm, which usually presents on the distal extremities of adults and sometimes children. It has a characteristic appearance, of a lobulated or multinodular neoplasm of moderately atypical epithelioid or spindled cells, vacuolated cells, and enlarged or bizarre cells with macronuclei, with prominent mixed inflammatory infiltrate, and variably myxoid stroma. However, the proportions of each component vary, making diagnosis difficult, particularly when tumors arise at unusual nonextremity sites. We describe a case of MIFS occurring as a primary neoplasm on the scalp of an 80-year-old male, which recurred locally after 2 years and developed extensive bilateral cervical lymph node metastases. MIFS is exceptionally rare in the head and neck, and it has been described only once on the scalp. This case showed classical histologic features, and additionally a high mitotic index and atypical mitoses, which may be suggestive of a poorer prognosis. This case highlights the need to consider MIFS in the differential diagnoses of pleomorphic tumors of the head and neck, and it adds to the small number of MIFS showing highly aggressive behavior.

Myxoinflammatory fibroblastic sarcoma: morphologic and genetic updates

Myxoinflammatory fibroblastic sarcoma (MIFS) is a malignant mesenchymal neoplasm most frequently arising in the distal extremities of adults, which usually behaves in a low-grade manner but is capable of metastasizing to local and distant sites, rarely leading to death. It is a rare tumor whose unusual morphology can lead to erroneous histologic diagnosis, either as a nonneoplastic (infectious or inflammatory) process or as a variety of neoplastic diseases. While its exact origin is uncertain, ultrastructural studies have shown at least some of the constituent cells to be modified fibroblasts. Distinct and reproducible genetic abnormalities identified in MIFS are translocation t(1;10)(p22:q24), with rearrangements of the TGFBR3 and MGEA5 genes associated with increased levels of FGF8, and formation of marker/ring chromosome 3, with amplification of the VGLL3 locus. Because these genetic abnormalities are shared by both MIFS and hemosiderotic fibrohistiocytic lipomatous tumor, it is thought that these 2 morphologically distinct neoplasms may comprise a spectrum of disease defined by these genetics. We review the literature on MIFS and discuss morphology (including that of MIFS/hemosiderotic fibrohistiocytic lipomatous tumor hybrid lesions), immunohistochemistry, the differential diagnosis, and recent molecular genetic developments.

Myxoinflammatory fibroblastic sarcoma: a clinicopathologic analysis of 104 cases, with emphasis on predictors of outcome

In this study, we examine the clinicopathologic features of 104 cases of myxoinflammatory fibroblastic sarcoma (MIFS), a low-grade, inflammatory fibromyxoid tumor with a predilection to distal extremity soft tissue, and attempt to identify factors predictive of aggressive behavior. The study cohort consisted of 49 male and 55 female patients ranging in age from 17 to 83 (mean, 42; median, 39) years. The tumor arose primarily on the dorsal aspect of the distal extremities as a solitary and usually painless mass. Tumors ranged in size from 0.5 to 15 (mean, 3.2; median; 2.4) cm. Microscopically, tumors consisted of variably cellular and inflamed fibromyxoid tissue growing as a lobulated mass or as multiple nodules within subcutaneous tissue or along tendinofascial planes. Tumor cells ranged from plump spindled to more epithelioid cells with enlarged, vesicular nuclei. Characteristic of the process was a strikingly bizarre cell with an inclusion body-like nucleolus (85% of cases) and/or a smudgy hyperchromatic nucleus (51%) present in all but 7 cases. The mitotic rate per 50 high-power field ranged from 0 to 13 (mean, 2,9; median, 2) mitoses. Twenty-two tumors demonstrated 1 or more of the following atypical features: (1) foci with complex sarcoma-like vasculature; (2) hypercellular areas; and (3) increased mitotic activity or atypical mitotic figures. Immunohistochemically, tumor cells demonstrated immunoreactivity for vimentin (100%), D2-40 (86%), CD34 (50%), keratin(s) (33%), CD68 (27%), actin(s) (26%), desmin (9%), S-100 protein (7%), and epithelial membrane antigen (6%). Thirty of 59 patients (51%) with follow-up data suffered (at least) 1 local recurrence, and 1 patient developed metastatic disease after multiple local recurrences. Completeness of initial surgical excision was the only clinicopathologic parameter that statistically correlated with a lower incidence of recurrence (P=0.004). Histologically atypical MIFS recurred more often than conventional tumors (67% vs. 47%), but the difference was not statistically significant (P=0.35). Our study shows that histologic features often associated with more aggressive sarcomas do not substantially impact the morbidity of MIFS, and complete surgical excision provides the best chance for disease-free survival.

Myxoinflammatory fibroblastic sarcoma in children and adolescents: clinicopathologic aspects of a rare neoplasm

Myxoinflammatory fibroblastic sarcoma (MIFS), originally described as a low-grade malignant soft-tissue tumor in adults, has recently been reported in children and in non-acral sites. This report describes the clinicopathologic features of a series of 5 MIFS in children and adolescents (3 males, 2 females), ranging in age from 5 to 17 years (mean, 13 years). These tumors presented as small, superficial, slowly growing soft-tissues masses of the scalp, neck, middle finger, forearm, and thigh. Histologically, the tumors were composed of spindled and plump polygonal cells with prominent nuclear pleomorphism, nuclear pseudoinclusions; large eosinophilic nucleoli; myxoid foci intermingled with spindled foci; and an accompanying inflammatory infiltrate of lymphocytes, plasma cells, and variable neutrophils. Immunohistochemical analysis revealed variable reactivity for CD34 and smooth muscle actin in the tumor cells. Genetic analysis in 3 cases showed no rearrangements of TGFBR3 or MGEA5. Follow up in 4 cases revealed no recurrence or metastasis. These 5 cases of childhood and adolescent MIFS demonstrate an expanded age range and topographic distribution and a favorable outcome. The differential diagnosis and importance of recognizing this rare neoplasm in young patients are discussed.

A case of lung metastasis in myxoinflammatory fibroblastic sarcoma: analytical review of one hundred and thirty eight cases

PURPOSE

Myxoinflammatory fibroblastic sarcoma (MIFS) is a rare soft tissue tumour first identified at the end of the 1990s. This study presents our experience and literature reviews focusing on risk of recurrence.

METHODS

Rizzoli Orthopaedic Institute database and literature were searched for patients with MIFS observed from 1997 to 2012. Data were analysed in a new database.

RESULTS

Five patients underwent surgery at our institute, and 133 cases were retrieved from the literature. Not all clinicopathological data were available: 76/138 were men (55%), median age was 45 [interquartile range (IQR) 34-56] years, median tumour size was three (IQR two to five) centimetres. Common sites of occurrence were hand (24%), fingers (23%) and foot (20%). Pain was present at diagnosis in 14/82 patients (17%), with a median duration of seven (IQR three to 12) months. Surgery was performed for a suspected benign tumour in 88 patients (74%). Resection was incomplete in 45/71 cases (63%); re-excision was performed in 32/45 (71%). At a median follow-up of 26 months, 26/118 patients (22%) developed recurrent disease; median time to recurrence was 15 months (IQR seven to 26). Actuarial relapse-free survival (RFS) at one, three and five years was 93%, 72% and 67%, respectively. At univariate analysis, only symptom duration of six months or less was significantly associated with a worse RFS (p = 0.046). Metastatic disease to lymph nodes and/or lungs was observed in four patients (3%).

CONCLUSIONS

Clinicopathological findings confirm the low-grade nature of MIFS. However, local recurrence occurs, and patients may be affected by aggressive forms with a potential for distant metastases. Follow-up is strongly advised.

Myxoinflammatory fibroblastic sarcoma of the finger: a case report

Myxoinflammatory fibroblastic sarcoma (MIFS) is a rare low-grade sarcoma that occurs in the subcutaneous tissue of the distal extremities. MIFS was first described in 1998. There are many differential diagnoses, and it can often be mistaken for several different inflammatory and neoplastic processes, which may require different treatment. There is much literature published for pathologists, but only a few reports for orthopedic surgeons to treat such tumors. It is significant and important to report this additional case of MIFS that occurred in the right ring finger and to acknowledge the very existence of the tumor as a differential diagnosis to be made by hand surgeons. Hand surgeons need to be mindful of MIFS, its nature, and the appropriate treatment necessary for this unique tumor.

Myxoinflammatory fibroblastic sarcoma: report of a case and review of the literature

Myxoinflammatory fibroblastic sarcoma (MIFS) is a low-grade sarcoma generally arising in adults. We present a case of MIFS in a 5-year-old boy with a palpable nodule in the subcutaneous tissue of the scalp. We carried out a literature review to evaluate the diagnostic patterns based on histologic and cytologic features and possible pitfalls and misdiagnoses. A systematic search for articles of interest published between 1995 and 2011 was performed in MEDLINE and PubMed using the words "myxoinflammatory fibroblastic sarcoma," "myxohyaline tumor," and "inflammatory myxoid tumor." Histology and cytology have a pivotal role in the differential diagnosis between MIFS and other potential soft-tissue mimics, such as nodular and proliferative fasciitis and inflammatory myofibroblastic tumor. Fine-needle aspiration cytology is a safe and useful tool for the diagnosis of pediatric patients with MIFS and is important for an accurate and precise preoperative workup to optimize subsequent management and treatment.