Ossifying fibromyxoid tumor of soft parts. Cytogenetic findings

Malignant Ossifying Fibromyxoid Tumor of the Chest Wall Metastasized to the Lung Even After Complete Resectioning of the Primary Tumor - A Case Report and a Comprehensive Review

An ossifying fibromyxoid tumor is a soft tissue neoplasm with ambiguous differentiation and low metastatic potential. Most cases involve the lower extremities, followed by the trunk, the upper extremities, and the head and neck region. It mainly arises in 40-70 years of age, and men dominate the disease's gender distribution. In the described types of ossifying fibromyxoid tumors, there are three variants: one is benign (typical), the second is malignant, which carries the risk of disease recurrence or metastases, and the third is atypical, which does not meet the criteria of either typical or malignant. Here, we present an interesting case of a malignant ossifying fibromyxoid tumor of the chest wall that metastasized to the lungs even after complete resection of the primary tumor. A 64-year-old man had a 4.0 cm malignant ossifying fibromyxoid tumor in his chest wall two years ago, and at that time, the tumor was removed entirely. On pathology review, it was noted to have 20 mitotic figures per 50 high-power fields, but no actual grade was given. He was given postoperative radiation. His recent computed tomography (CT) chest with contrast showed a new right upper lung lobe nodule measuring 0.78 cm compared to the previous contrast-enhanced CT chest six months ago. It was worrisome for metastasis. F-18 FDG positron emission tomography scan revealed sub-centimetric pulmonary nodules in the right upper lobe. Right upper lobe lung biopsy showed spindle cell neoplasm morphologically consistent with the patient's known history of malignant ossifying fibromyxoid tumor. Biopsy demonstrated fragments of the bronchial wall and alveolated lung parenchyma with a focal spindle cell proliferation demonstrating a fibromyxoid matrix. The patient was referred to the oncologist for further management. In conclusion, aggressive malignant ossifying fibromyxoid tumors can be found in atypical locations, e.g., the chest wall. Therefore, early diagnosis is crucial because of the high chances of metastasis to distant organs (including the lung) even after complete resection of the primary tumor. Even in asymptomatic patients, it is necessary to complete long-term follow-up for recurrence and metastasis surveillance of ossifying fibromyxoid tumors. Early recognition of recurrence or metastasis can decrease morbidity and mortality and improve overall organ function and patient survival.

Ossifying Fibromyxoid Tumor: A Review With Emphasis on Recent Molecular Advances and Differential Diagnosis

CONTEXT.—

Ossifying fibromyxoid tumor (OFMT) is a rare, slow-growing mesenchymal neoplasm of uncertain histogenesis with intermediate malignant potential.

OBJECTIVE.—

To highlight the most important diagnostic features, including morphologic, immunohistochemical, and molecular findings; to provide comparisons to other entities in the differential diagnosis; and to provide a summary of the clinical features and outcomes in cases reported to date.

DATA SOURCES.—

The data sources include recently published literature encompassing OFMT and tumors in the histologic differential diagnosis, and cases from institutional files.

CONCLUSIONS.—

Ossifying fibromyxoid tumor is important to recognize because of its low-grade morphology but potential for recurrence and metastasis. Recent molecular analysis has expanded the morphologic spectrum of OFMT, with additional cases discovered that are enriched for aggressive behavior. The diagnosis can often be rendered through a combination of morphology and coexpression of S100 protein and desmin, although only a minority of cases described contain all of these primary features. In cases that do not have all of these features, a high index of suspicion guided by morphology and exclusion of other tumors in the histologic differential diagnosis can lead to the correct diagnosis. Growing access to molecular genetic testing will become increasingly important for correct diagnosis of tumors at the ends of the morphologic spectrum.

Ossifying fibromyxoid tumor: a study of 6 cases of atypical and malignant variants

Ossifying fibromyxoid tumors (OFMT) of soft parts are rare, slow-growing tumors that have potential for local recurrence and may metastasize. While OFMT originally was considered benign, several cases of malignant OFMT have been documented. There is no universally accepted risk stratification, although this study emphasizes the importance of utilizing histology, immunohistochemistry and FISH in establishing the diagnosis. Herein, we describe six cases of atypical and malignant OFMT with differences in morphologic features, 5 of which display the proposed morphological criteria for malignancy. The patients were mostly male (M=5, F=1) with an age range of 33-69 years. The tumors arose from the extremities (3 cases), the shoulder (1 case), the head and neck area (1 case), and the paraspinal area (1 case). One tumor had high grade and overtly sarcomatous changes, while another invaded the underlying clavicle. Two cases showed cytological atypia and necrosis. Fluorescence in situ hybridization (FISH) detected rearrangement of the PHF1 gene in 5 cases. All cases were positive for EAAT4 and actin by immunohistochemistry, while negative for desmin. Three tumors were immunoreactive for S100 protein. INI-1 immunohistochemical staining was conserved in all but 2 cases in which a mosaic loss of expression was noted. All but two patients are currently alive and free of disease.

Expanding the molecular signature of ossifying fibromyxoid tumors with two novel gene fusions: CREBBP-BCORL1 and KDM2A-WWTR1

Ossifying fibromyxoid tumor (OFMT) is an uncommon mesenchymal neoplasm of uncertain differentiation and intermediate malignant potential. Recurrent gene fusions involving either PHF1 or BCOR have been found in 85% of OFMT, including typical and malignant examples. As a subset of OFMT still lack known genetic abnormalities, we identified two OFMTs negative for PHF1 and BCOR rearrangements, which were subjected to transcriptome analysis for fusion discovery. The RNA sequencing found a novel CREBBP-BCORL1 fusion candidate in an axillary mass of a 51 year-old male and a KDM2A-WWTR1 in a thigh mass of a 36 year-old male. The gene fusions were validated by RT-PCR and FISH in the index cases and then screened by FISH on 4 additional OFMTs lacking known fusions. An identical CREBBP-BCORL1 fusion was found in an elbow tumor from a 30 year-old male. Both OFMTs with CREBBP-BCORL1 fusions had areas of typical OFMT morphology, exhibiting uniform round to epithelioid cells arranged in cords or nesting pattern in a fibromyxoid stroma. The OFMT with KDM2A-WWTR1 fusion involved dermis and superficial subcutis, being composed of ovoid cells in a fibromyxoid background with hyalinized giant rosettes. The S100 immunoreactivity ranged from very focal to absent. Similar to other known fusion genes in OFMT, BCORL1, CREBBP and KDM2A are also involved in histone modification. In summary, we expand the spectrum of molecular abnormalities in OFMT with 2 novel fusions, CREBBP-BCORL1 and KDM2A-WWTR1, further implicating the epigenetic deregulation as the leading pathogenetic mechanism in OFMT. © 2016 Wiley Periodicals, Inc.

Ossifying Fibromyxoid Tumor May Express CD56 and CD99: A Case Report

Ossifying fibromyxoid tumor (OFMT) is an uncommon soft tissue neoplasm characterized by a combination of myxoid and/or fibrous stroma with areas of ossification. Although most authors postulate a neuroectodermal origin for this peculiar tumor, there is no agreement in the literature regarding its histogenesis. In this article, we present the immunohistochemical findings of a case of a 39-year-old white male with an OFMT of the soft tissue in the mandibular region. The tumor was positive to S-100 protein, glial fibrillary acidic protein, CD99, CD56 and negative to smooth muscle actin, cytokeratins AE1/AE3, epithelial membrane antigen, and CD68. To the best of our knowledge, this is the first case reported to be positive to CD56 and CD99. Immunoreactivity to these two antibodies, together with reactivity for S-100 protein and glial fibrillary acidic protein, suggests that OFMT is of a neuroectodermal origin. In our opinion, in the absence of reactivity to at least one neuroectodermal marker one should seriously question a diagnosis of OFMT.

Diagnostically Challenging Epithelioid Soft Tissue Tumors

In this article, we focus on the histologic features, differential diagnosis, and potential pitfalls in the diagnosis of epithelioid sarcoma, alveolar soft part sarcoma, clear-cell sarcoma, ossifying fibromyxoid tumor, and malignant extrarenal rhabdoid tumor. Numerous other soft tissue tumors also may have epithelioid variants or epithelioid features. Examples include epithelioid angiosarcoma, epithelioid malignant peripheral nerve sheath tumor, epithelioid gastrointestinal stromal tumor, and perivascular epithelioid cell tumor, among others.

Ossifying Fibromyxoid Tumor: An Update

Ossifying fibromyxoid tumor (OFMT) is a rare soft tissue neoplasm of uncertain differentiation, initially described by Enzinger and colleagues. Until now, nearly 300 such cases have been reported worldwide. The histogenesis of these tumors remains controversial. These tumors show characteristic imaging findings and exhibit a spectrum of histopathologic features, including classical and atypical subtypes. Local recurrences and, occasionally, distant metastases have also been reported. A complete tumor resection forms the preferred treatment modality for these tumors, along with follow-up, as these tumors have an uncertain malignant potential. Lately, certain “molecular signatures” underlying OFMTs have been described that can further aid in reaching an accurate diagnosis for these tumors and unraveling their pathogenesis. This article is a review of the clinical, radiologic, histopathologic, and molecular features of OFMTs.

Ossifying fibromyxoid tumor: morphology, genetics, and differential diagnosis

Ossifying fibromyxoid tumor (OFMT) is a soft tissue neoplasm of uncertain differentiation and intermediate (rarely metastasizing) biologic potential, with typical morphologic features, of an encapsulated, lobulated tumor comprising uniform polygonal cells within fibromyxoid stroma, which is surrounded by or contains metaplastic bone, classically as a peripheral rim of lamellar bone. Ossifying fibromyxoid tumor can arise at almost any site, although most frequently occurs within the extremities and trunk. Although most behave in a benign fashion, tumors can rarely show atypical or malignant features. It is now established that OFMTs represent translocation-associated tumors, with up to 85% associated with recurrent gene rearrangements, mostly involving the PHF1 gene (including in typical, atypical, and malignant neoplasms), with EP400-PHF1 in approximately 40% of tumors, and ZC3H7B-BCOR, MEAF6-PHF1, and EPC1-PHF1 fusions also described. Correct diagnosis is clinically important to ensure correct treatment and prognostication, both to avoid overdiagnosing OFMT as a malignant neoplasm such as osteosarcoma and also because of the propensity for aggressive behavior in a small number of OFMT. We review OFMT, with emphasis on the morphologic spectrum, recent molecular genetic findings, and the differential diagnosis.

Imaging findings of ossifying fibromyxoid tumor with histopathological correlation: A case report

Ossifying fibromyxoid tumor (OFMT) is a soft tissue tumor of uncertain lineage that most often arises in the extremities of adults. Imaging findings of this uncommon tumor are rare. We, herein, present a case of OFMT occurring in the left thigh of a 36-year-old male. Radiological examinations revealed a well-circumscribed subcutaneous mass with an incomplete shell of peripheral ossification, suggesting a benign condition. Following complete excision, the mass was histopathologically diagnosed as an OFMT. The patient demonstrated no evidence of local recurrence within 11 months of follow-up. We describe the clinicopathological and radiological features, and review the relevant literature.

Updates on the cytogenetics and molecular cytogenetics of benign and intermediate soft tissue tumors

SOFT TISSUE TUMORS ARE CLASSIFIED ACCORDING TO THEIR HISTOLOGICAL RESEMBLANCE TO NORMAL ADULT TISSUES AND CAN BE GROUPED INTO THE FOLLOWING CATEGORIES BASED ON METASTATIC POTENTIAL: benign, intermediate (locally aggressive), intermediate (rarely metastasizing) and malignant. Over the past two decades, considerable progress has been made in our understanding of the genetic background of soft tissue tumors. Traditional laboratory techniques, such as cytogenetic analysis and fluorescence in situ hybridization (FISH), can be used for diagnostic purposes in soft tissue pathology practice. Moreover, cytogenetic and molecular studies are often necessary for prognostics and follow-up of soft tissue sarcoma patients. This review provides updated information on the applicability of laboratory genetic testing in the diagnosis of benign and intermediate soft tissue tumors. These tumors include nodular fasciitis, chondroid lipoma, collagenous fibroma (desmoplastic fibroblastoma), giant cell tumor of tendon sheath (GCTTS)/pigmented villonodular synovitis (PVNS), angiofibroma of soft tissue, myxoinflammatory fibroblastic sarcoma (MIFS) and ossifying fibromyxoid tumor (OFMT).

Ossifying fibromyxoid tumor of soft parts: a clinicopathologic, proteomic, and genomic study

Ossifying fibromyxoid tumor (OFMTs) of soft parts is a rare soft tissue and bone tumor of borderline malignancy displaying an uncertain line of differentiation. The existence of fully malignant OFMT is controversial. To better understand the natural history and line of differentiation taken by OFMT, we studied 46 cases by light microscopic, immunohistochemical (IHC), genomic, proteomic, and fluorescence in situ hybridization (FISH) methods. Cases were classified according to the 2003 Folpe and Weiss system. Clinical and follow-up information was obtained. IHC for S-100 protein, desmin, epithelial membrane antigen (EMA), cytokeratins, smooth muscle actin (SMA), INI-1, neurofilament protein (NFP), CD56d excitatory amino acid transporter-4 (EAAT4), and MUC4 was performed on formalin-fixed, paraffin-embedded (FFPE) tissues. Gene expression profiling and proteomic studies were conducted on FFPE tissues from 13 and 5 cases, respectively. FISH for INI-1 was performed on 10 cases. The 46 tumors arose in 29 men and 17 women (median age, 52 y; range 39 to 63 y) and involved the proximal (N=17) and distal extremities (N=13), head and neck (N=9), and trunk (N=5). Median tumor size was 5.4 cm (range, 1.0 to 21.0 cm). Cases were classified as typical OFMT (26 of 46, 57%), atypical OFMT (5 of 46, 11%), and malignant OFMT (15 of 46 cases, 32%). Clinical follow-up (27 cases, median 55 months' duration) showed all patients with typical and atypical OFMT to be alive without disease. Adverse events, including 3 local recurrences, 3 metastases, and 3 deaths, were seen only in malignant OFMT. IHC results were as follows: S-100 protein (30 of 41, 73%), desmin (15 of 39, 38%), cytokeratin (4 of 35, 11%), EMA (5 of 32, 16%), SMA (2 of 34, 6%), INI-1 (lost in mosaic pattern in 14 of 19, 74%), EAAT4 (31 of 39, 80%), MUC4 (3 of 14, 21%), NFP (8 of 10, 80%) and CD56 (6 of 14, 43%). Gene expression profiling showed typical and malignant OFMTs to cluster together, distinct from schwannian tumors. Proteomic study showed expression of various collagens, S-100 protein, and neuron-related proteins. FISH showed INI-1 deletion in 5 of 7 (71%) cases. We conclude that malignant OFMTs exist and may be recognized by the previously proposed criteria of Folpe and Weiss. Expression of neuron-related markers, in addition to Schwann cell and cartilage-associated markers, suggests a "scrambled" phenotype in OFMTs. Loss of INI-1 or other genes on 22q is likely important in the pathogenesis of these rare tumors.

Paraspinal malignant ossifying fibromyxoid tumor with spinal involvement

Ossifying fibromyxoid tumors (OFT), first described in 1989 by Enzinger et al., are rare lesions; malignant OFT (MOFT) are even rarer. We report a large recurrent paraspinal MOFT invading the spine and causing epidural compression in a 70-year-old male, despite prior debulking and radiotherapy. Paraspinal involvement of these tumors has been reported only twice before. We describe its imaging, pathology, and also review the pertinent literature.

Ossifying fibromyxoid tumour of the sphenoid sinus

INTRODUCTION

Ossifying fibromyxoid tumour is a recently described, rare but morphologically distinctive soft tissue neoplasm characterised by a combination of myxoid and/or fibrous stroma with areas of ossification. Although most authors postulate a neuroectodermal origin for this peculiar tumour, there is no agreement in the literature regarding its histopathogenesis. To our knowledge, this is the first reported case of ossifying fibromyxoid tumour involving the sphenoid sinus. HISTOLOGICAL FINDINGS: Tumour of low cell density, composed of small, spindle-shaped or stellate cells with small, irregular nuclei set in a fibromyxoid stroma.

MANAGEMENT

Following discussion at the skull base multidisciplinary team meeting, a combined surgical team including an otorhinolaryngologist and a neurosurgeon carried out resection of the lesion, using an endoscopic transnasal approach, followed by reconstruction of the defect.

CONCLUSIONS

An awareness of the distinctive histopathological features of ossifying fibromyxoid tumour, and of its clinical effects, is crucial to establishing a definitive diagnosis and thereby instituting appropriate management. This case report also reinforces the evolving role of the endoscopic transnasal approach in the management of inflammatory and neoplastic disease involving the skull base. This is increasingly being made possible by close collaboration between multiple surgical specialties, including otorhinolaryngology and neurosurgery.

Ossifying fibromyxoid tumor in the mandibular gingiva: case report and review of the literature

BACKGROUND

Ossifying fibromyxoid tumors (OFTs) are uncommon soft tissue neoplasms. Only one case arising in the gingiva has been described.

METHODS

A 21-year-old woman presented with a painless exophytic mass located in the right posterior mandibular gingiva, which was identified 6 months earlier. Radiographs showed irregular calcifications inside the lesion, discrete irregularity of alveolar bone, and integrity of buccal and lingual cortical bone. An incisional biopsy was performed based on the clinical diagnostic hypothesis of peripheral ossifying fibroma or peripheral giant cell granuloma. Microscopic features were compatible with the diagnosis of ossifying fibroma. The entire mass was excised and submitted to histopathologic and immunohistochemical analysis.

RESULTS

Histopathologic analysis revealed proliferation of round to spindle-shaped cells arranged in cords and nests and embedded in a fibromyxoid matrix. An incomplete shell of bone trabeculae located beneath the fibrous pseudocapsule was observed at the periphery. Immunohistochemical analysis showed positivity for vimentin and S-100 protein and negativity for smooth muscle actin, muscle-specific actin, and glial fibrillary acidic protein. The definitive diagnosis was OFT. The patient showed no clinical signs of recurrence 7 months after surgical excision.

CONCLUSIONS

OFTs located in the gingiva are extremely rare. At this site, these tumors are clinically indistinguishable from other reactive or neoplastic lesions. Although many cases present an indolent biologic behavior, the local recurrence of OFTs has been reported; therefore, long-term follow-up is mandatory.

Ossifying Fibromyxoid Tumor: Modified Myoepithelial Cell Tumor? Report of Three Cases with Immunohistochemical and Electron Microscopic Studies

Ossifying fibromyxoid tumors (OFMT) are rare soft tissue tumors of uncertain histogenesis and clinical behavior. Since Enzinger, Weiss, and Liang first described 59 examples in 1989 (Am Surg Pathol. 13:817-827), approximately 150 cases have been reported. Their clinicopathologic features are fairly well characterized and their histogenesis remains unknown. Three examples of soft tissue tumors with typical histopathologic characteristics of OFMT were studied: case 1, a 43-year-old female with a 2.5-cm tumor of the back; case 2, a 56-year-old man with an 8-cm thigh mass; and case 3, an 81-year-old female with a 13.5-cm buttock tumor. For immunohistochemistry, formalin-fixed, paraffin-embedded tissue sections were stained with antibodies against cytokeratin, smooth muscle actin, desmin, vimentin, S-100 protein, EMA, and collagen type IV using standard ABC-peroxidase methods. For electron microscopy, tissue samples fixed in EM-grade buffered formalin were processed according to routine methods. Immunohistochemistry showed that the tumor cells were positive for vimentin and S-100 protein in all 3 cases. Stains for collagen type IV revealed diffusely positive staining in the stroma with a tendency for stronger staining around the cell borders in 2 out of 3 cases. Desmin was positive in one and actin was positive in one other case. By electron microscopy, tumor cells were characterized by centrally located round to oval nuclei with varying amounts of cytoplasm containing scanty cytoplasmic organelles. There were rare profiles of rough-surfaced endoplasmic reticulum (RER) and rare mitochondria with areas of condensed intermediate filaments. No tonofilaments or actin filaments were present. There were multiple short web-like processes, some of which were attached to that of neighboring cells by primitive cell junctions. In all 3 cases, lesional cells showed external lamina (EL), which was abundant in case 1, forming redundant scrolls frequently. In case 2, EL was less prominent and incomplete, and interrupted portions of EL were present only along the periphery of cell columns or nests bordering the stroma. In case 3, which behaved as a malignant tumor, the tumor cells were less differentiated spindle cells with primitive cellular features, and EL was rarely found along the short span of tumor cell borders. In this study, tumor cells in OFMT were polygonal to stellate often with multiple short cytoplasmic processes. The tumor cells were found to form cell clusters attached by primitive intercellular junctions between cytoplasmic processes forming intercellular bridges. The cell borders facing the stroma around cell clusters tended to be flat and had incomplete EL, while no EL was present along the cell borders facing the inner aspect of cell clusters. These ultrastructural findings together with immunophenotypic expression of S-100 protein presented closer resemblance to those of modified myoepithelial cells in pleomorphic adenomas of salivary glands and skin appendages rather than peripheral nerve sheath tumors. The authors conclude that these findings render more support to the hypothesis of myoepithelial histogenesis of OFMT. They also conclude that ultrastructural study not only helps accurate diagnosis, but also may aid in predicting malignant behavior by the degree of deviation from the typical examples of OFMT.

Ossifying fibromyxoid tumor of soft parts with clonal chromosomal aberrations

Ossifying fibromyxoid tumor (OFMT) is a rare but morphologically distinctive soft-tissue tumor. The histologic origin of this tumor is not clearly known, but its various features suggest a schwannian, neuronal, or chondroid origin. We herein report a case of a typical OFMT that occurred in the shoulder of a 65-year-old man. The karyotype exhibited the following complex numeric and structural aberrations: 42 approximately 46,XY,-Y,add(1)(q42),add(6)(p21),t(10;18)(q26;q11),der(11)t(11;15)(q23;q15),add(12)(q13),ins(14;?)(q13;?),-15,+mar. Combined with several previously reported studies, these aberrations could not identify a common cytogenetic abnormality in OFMT.

An unusual presentation of ossifying fibromyxoid tumor of the mandible: a case report

A 13-year-old boy who complained rapid swelling on the left side of mandible is presented. Histopathological examination revealed ossifying fibromyxoid tumor (OFMT). OFMT is a rare soft-tissue neoplasm that occurs usually in the subcutaneous tissue of the extremties. Head and neck involvement is relatively rare. In this case, we present the diagnosis, surgical treatment and long-term follow-up of an OFMT due to its unusual site of occurrence. The precise clinical behavior of atypical and malignant types of OFMTs is still unclear. Thus, histopathology report is important, leading surgeon to decide how often and how long to follow-up patient with OFMT.

Subcutaneous ossifying fibromyxoid tumor

Ossifying fibromyxoid tumor (OFMT) is an uncommon neoplasm occurring predominantly in the deep soft tissues of the trunk and proximal extremities. The lineage of this rare tumor to date is still uncertain. We present a case of a subcutaneous OFMT that recurred 8 years after initial resection. The histological findings of the primary and recurrent lesions are compared along with the histologic features possibly associated with aggressiveness. Dermatopathologists should consider OFMT in the differential diagnosis of subcutaneous neoplasms with a myxoid matrix.

Ossifying fibromyxoid tumor of soft parts presenting as a scalp cyst

BACKGROUND

Ossifying fibromyxoid tumor of soft parts (OFMT) is a rare mesenchymal neoplasm of intermediate malignant potential. The tumor most commonly occurs on the extremities with a male predominance. We present an unusual case of OFMT occurring as a cystic lesion on the scalp of a female.

CASE HISTORY

A 67-year-old woman presented with a 6-year history of a well demarcated cystic scalp mass. Physical examination revealed a slightly movable, multilobular mass of the left parietal scalp which was subsequently excised. Histological evaluation revealed an OFMT comprised of bland, small cells and a thick collagenous capsule containing an incomplete rim of lamellar bone.

CONCLUSION

OFMT is an unusual tumor which can usually be considered as having an intermediate risk of malignancy. It generally occurs in the extremities with a male predominance. The clinical differential for a cystic mass on the scalp is broadened by this unusual case of an OFMT.

Mediastinal and Pulmonary Metastases of Malignant Ossifying Fibromyxoid Tumor

Ossifying fibromyxoid tumor is usually a benign tumor. However some of these tumors with histologic and clinical evidence of malignancy have also been reported and little information is available regarding surgery for metastatic ossifying fibromyxoid tumor. We present a case involving extensive excision of a huge metastatic ossifying fibromyxoid tumor occupying the upper mediastinum and upper half of the right hemithorax.

Ossifying fibromyxoid tumor of the nasal septum

The fibromyxoid tumor is quite a rare soft tissue tumor and typically presents as an ossifying fibromyxoid tumor (OFMT) in the subcutis of the extremities of adults. Most authors favour schwannian or chondroid origin of this lesion with somehow uncertain biologic dignity. Local recurrence is seen in 27% of patients after primary excision. We present a case of a fibromyxoid tumor of the nasal septum in a 49-year-old female who complained of nasal airway obstruction and enlargement of the right contour of the nose. Endonasal, endoscopic tumor excision was performed. The tumor contained spindle-shaped and polygonal cells, mucoid pseudocysts and a fibromyxoid stroma with local calcifications. The clinical behaviour of OFMT in general is benign but some reports have documented atypical tumors with histologic signs of malignancy. Complete local resection is the treatment of choice. Because of the high rate of local recurrence, clinical follow-up examinations are necessary.

Ossifying fibromyxoid tumor of the ethmoid sinus in a newborn: report of a case and literature review

Ossifying fibromyxoid tumor (OFT) of soft parts is a benign soft tissue tumor commonly located in the extremities. In this paper, a 3-week-old boy presented with left nasal mass at birth. He was found to have an OFT involving the ethmoid sinus. To the best of our knowledge, this is the first reported case of OFT in a newborn with involvement of the sinuses. This rare tumor should alert Pediatric Otolaryngologists to include it in the differential diagnosis of pediatric soft tissue tumors in sinuses.

Ossifying fibromyxoid tumor of soft parts: a clinicopathologic study of 70 cases with emphasis on atypical and malignant variants

The ossifying fibromyxoid tumor of soft parts (OFMT) is an uncommon soft tissue neoplasm of uncertain lineage. Approximately 100 cases of OFMT have been reported. Although the majority behave in a benign fashion, very rare tumors with histologic and clinical evidence of malignancy have been reported. Criteria for malignancy in OFMT have not as yet been defined. Seventy cases of OFMT were retrieved from our consultation archives and studied with respect to patient age and sex, tumor site and size, growth pattern, percentage of typical OFMT, cellularity and nuclear grade, mitotic figures (MF)/50 high power fields (HPF), atypical mitoses, necrosis, vascular invasion, and the presence of bone. Immunohistochemistry for pancytokeratin, S-100 protein, smooth muscle actin, desmin, and collagen II was performed on a subset of cases. Follow-up information was obtained from the submitting pathologists and clinicians. The Fisher exact test was used for statistical analysis. Patients (39 male, 31 female) ranged in age from 14 to 83 years (median 49 years). The tumors occurred primarily as subcutaneous or deeply seated masses in the trunk and proximal extremities and ranged from 1 to 14 cm (median 4.0 cm). The percentage of typical OFMT present in each case ranged from 0% to 100% (median 70%), and bone was present in 44 cases (63%). Mitotic activity ranged from 0 to 40 MF/50 HPF (median 2 MF/50 HPF), necrosis was present in 12 cases (17%), and vascular invasion was seen in 8 cases (11%). High cellularity or high nuclear grade was seen in 14 and 13 cases, respectively. Immunohistochemical results were as follows: S-100 protein (33 of 55, 60%), pancytokeratin (5 of 48, 10%), smooth muscle actin (2 of 44, 5%), desmin (5 of 39, 13%), and collagen II (1 of 26, 4%). Follow-up (51 cases, mean 54 months, median 36 months, range 5-151 months) showed local recurrences in nine patients and metastases in eight patients. Currently, 41 patients are disease free, 6 are alive with disease, 4 are dead of disease, and 1 died of other causes. The presence of high cellularity (p = 0.002), high nuclear grade (p = 0.001), or >2 MF/50 HPF (p = 0.004) were significantly associated with the development of metastatic disease and local recurrence. Infiltrative growth was also associated with increased risk of local recurrence (p = 0.03). We conclude that the histologic spectrum of OFMT is broader than previously appreciated, as many clinically benign cases display moderate cellularity, nuclear enlargement, or have identifiable mitotic figures. Our results strongly suggest that OFMT with 1) high nuclear grade or 2) high cellularity and mitotic activity of >2 MF/50 HPF should be regarded as sarcomas with significant potential for metastasis and untoward outcome ("malignant OFMT"). The remainder can be considered within the spectrum of OFMT, recognizing that even these lesions possess a risk, albeit very low, of metastasis. Consequently, OFMT should be considered tumors of intermediate malignancy. Their line of differentiation remains unclear, although we suggest they may belong to the category of translocation-associated sarcomas, not all of which recapitulate a normal line of differentiation.