Chondromyxoid fibroma of the lumbar facet joint: A case report

Chondromyxoid fibroma (CMF) is a rarely documented benign osseous neoplasm, particularly with respect to its incidence in the lumbar spinal region. CMF predominantly manifests in vertebral bodies, exhibiting atypical emergence in ancillary anatomical sites. The present report describes, to the best of our knowledge, the second documented instance of CMF originating from the lumbar facet joint. The present case provides an example of CMF in the lumbar facet joint precipitating spinal canal stenosis, thereby engendering neurological manifestations in the lower extremities due to neoplastic proliferation through the intervertebral foramen. The present therapeutic intervention entailed surgical excision of the neoplasm concomitant with facet joint arthrodesis, with the objective of achieving comprehensive neoplasm eradication, ameliorating the symptomatology and safeguarding the spinal structural integrity of the patient. The present study aimed to illustrate the clinical implications of this rare neoplasm, thereby elucidating the diagnostic quandaries and therapeutic complexities associated with CMF in the lumbar facet joint. In addition, the present study aimed to augment the existing knowledge for the diagnosis and clinical management of CMF.

GRM1-Rearranged Chondromyxoid Fibroma With FGF23 Expression: A Potential Pitfall in Small Biopsies

The clinical, radiological, and histopathological features of chondromyxoid fibroma can sometimes resemble those of other benign or malignant tumors. Recently, recurrent GRM1 rearrangements have been identified in chondromyxoid fibroma, and GRM1 positivity by immunohistochemistry has emerged as a dependable surrogate marker for this molecular alteration. Phosphaturic mesenchymal tumor is a rare tumor that often exhibits overexpression of fibroblastic growth factor 23 (FGF23) through various mechanisms. In this report, we present a case of GRM1-rearranged chondromyxoid fibroma that also exhibited FGF23 expression via in situ hybridization, posing significant diagnostic challenges during workup of the initial core biopsy. We hope that this case can serve as an educational resource, shedding light on a rare diagnostic pitfall.

Chondromyxoid Fibroma of the Distal Tibia: A Rare Case Report

Chondromyxoid fibroma is one of the rarest bone tumours, occurring most frequently in adult men in their second and third decades. It generally affects the metaphysis of long bones, particularly the femur and tibia. Diagnosis can pose differential challenges with various tumor types, particularly chondrosarcoma, requiring separate management. We present a case of chondromyxoid fibroma of the distal tibia detected by soft tissue swelling. Clinical, epidemiological and radiological aspects will be discussed.

Chondromyxoid fibroma: A rare benign tumor with potential for local recurrence

Chondromyxoid fibroma is one of the rarest benign cartilaginous tumors accounting for less than 0.5% of bone tumors and mostly found in the metaphysis of long bones. Diagnosis is by histology showing lobular pattern with stellate-shaped cells in a myxoid or chondroid background. Often they can be misdiagnosed as chondrosarcomas. Recommended treatment approach is surgically excision due to the high risk of malignancy. Although benign, local recurrence is common as presented from this case report.

GRM1 Immunohistochemistry Distinguishes Chondromyxoid Fibroma From its Histologic Mimics

Chondromyxoid fibroma (CMF) is a rare benign bone neoplasm that manifests histologically as a lobular proliferation of stellate to spindle-shaped cells in a myxoid background, exhibiting morphologic overlap with other cartilaginous and myxoid tumors of bone. CMF is characterized by recurrent genetic rearrangements that place the glutamate receptor gene GRM1 under the regulatory control of a constitutively active promoter, leading to increased gene expression. Here, we explore the diagnostic utility of GRM1 immunohistochemistry as a surrogate marker for GRM1 rearrangement using a commercially available monoclonal antibody in a study of 230 tumors, including 30 CMF cases represented by 35 specimens. GRM1 was positive by immunohistochemistry in 97% of CMF specimens (34/35), exhibiting moderate to strong staining in more than 50% of neoplastic cells; staining was diffuse (>95% of cells) in 25 specimens (71%). Among the 9 CMF specimens with documented exposure to acid decalcification, 4 (44%) exhibited diffuse immunoreactivity (>95%) for GRM1, whereas all 15 CMF specimens (100%) with lack of exposure to decalcification reagents were diffusely immunoreactive ( P =0.003). High GRM1 expression at the RNA level was previously observed by quantitative reverse transcription polymerase chain reaction in 9 CMF cases that were also positive by immunohistochemistry; low GRM1 expression was observed by quantitative reverse transcription polymerase chain reaction in the single case of CMF that was negative by immunohistochemistry. GRM1 immunohistochemistry was negative (<5%) in histologic mimics of CMF, including conventional chondrosarcoma, enchondroma, chondroblastoma, clear cell chondrosarcoma, giant cell tumor of the bone, fibrous dysplasia, chondroblastic osteosarcoma, myoepithelial tumor, primary aneurysmal bone cyst, brown tumor, phosphaturic mesenchymal tumor, CMF-like osteosarcoma, and extraskeletal myxoid chondrosarcoma. These results indicate that GRM1 immunohistochemistry may have utility in distinguishing CMF from its histologic mimics.

Chondromyxoid Fibroma of the Rib: A Rare Benign Tumor With Potential for Local Recurrence

Chondromyxoid fibroma (CMF) is a benign cartilaginous tumor that typically occurs in the long bones of young adult males, with the clinical presentation varying from asymptomatic to localized pain, swelling, and movement restriction. We report an unusual presentation of CMF involving a rib, along with a literature review of the management of CMF. Although benign, local recurrence is not uncommon, and malignant transformation has been reported on rare occasions. En bloc surgical excision, with adequate tumor-free resection margins, of radiologically suspected chondromyxoid fibroma is crucial for the treatment and confirmation of diagnosis. A high index of suspicion, adequate treatment, and follow-up are critical for the successful management of these uncommon benign chondroid tumors.

Craniofacial Chondromyxoid Fibromas: A Systematic Review and Analysis Based on Anatomic Locations

BACKGROUND

Craniofacial chondromyxoid fibromas (CMF) are a rare benign tumor of cartilaginous origin. They are commonly misdiagnosed due to the paucity of information on tumor characteristics. We performed a systematic review to characterize CMF located in different regions of the craniofacial skeleton.

METHODS

A search of the literature was executed using the search phrase "chondromyxoid fibroma" and included articles from 1990 - 2020. Sixty-eight articles met the inclusion criteria, with a total of 91 patients with analyzable data (22 with calvarial and 69 with sinonasal tumor locations). Descriptive analyses were performed to compare pre-selected characteristics between the two groups.

RESULTS

Sinonasal CMF frequently presented with cranial nerve palsy and expectedly had a high rate of nasal symptoms. Calvarial tumors frequently presented with an external mass and headache. Gross total resection (GTR) was achieved in a higher proportion of cases in the calvarial group versus the sinonasal group (83.3% vs 53.1%). Overall recurrence rate at 17.7% was higher in sinonasal CMF compared to the calvarial tumors at 8.3%. Recurrences after GTR were similar in the sinonasal and calvarial groups (9.7% vs 9.1%). In patients who did not achieve GTR, recurrence was higher in the sinonasal compared to the calvarial group (27.6% vs 0%).

CONCLUSION

Craniofacial CMF in calvarial and sinonasal locations have distinct clinical characteristics and response to treatment. Sinonasal lesions tend to have higher recurrence compared to calvarial CMF. Performance of GTR is associated with decreased recurrence in all CMF.

[Retrofacial approach to remove a rare chondromyxoid fibroma of the infralabyrinthine space]

A very rare case of 46-yaer-old woman with chondromyxoid fibroma (CMF) of infralabyrinthine area of temporal bone was described in this article. The only manifestation of this disease was a severe temporary pain in the postauricular area with irradiation in the occipital bone and headache during the last 3 months. A detail description of the CT scan and MRI data was presented. Tumor removing was performed through the retrofacial approach with combination of the microscopic and endoscopic assistance technique, which allows to had a good visualization and controlling of tumor separation from the vital structures with hearing and facial nerve function preserve. Also, we presented a brief review of literature with differential diagnosis of the CMF of the temporal bone, which conducted to minimize the diagnosis mismatches in the otologic and head and neck practice and to optimize the treatment of patients with such tumor.

Chondromyxoid Fibroma of the Sacral Spine

Background and Importance. Chondromyxoid fibromas are rare tumors of cartilaginous origin typically found in long bones. They usually present during the second and third decades of life. In this case report, we describe the case of a 60-year-old male who presented with back pain and was later found to have a sacral mass. Further immunohistochemical analysis determined that the mass was a chondromyxoid fibroma. Clinical Presentation. A 60-year-old male presented with worsening lower back pain over the course of 2 years. Magnetic resonance imaging demonstrated a destructive mass centered at S4 with heterogeneous enhancement. The patient underwent an S3-to-Co1 laminectomy for gross total resection of the tumor. Histology demonstrated a biphasic, lobulated appearance, characteristic of a chondromyxoid fibroma. The tissue stained faintly positive for multicytokeratin, and it was negative for markers S-100 protein and brachyury, indicating that it was not a chordoma. Conclusion. Only 8 cases have documented sacral chondromyxoid fibroma. As these are exceedingly rare tumors, especially within the sacral spine, the differential diagnosis includes other malignant tumors more likely to be found in the spine, particularly chordomas and chondrosarcomas. Immunohistochemistry and histology are essential in making a definitive diagnosis. This case provides a comprehensive illustration of the clinical presentation, radiographic findings, and immunohistochemistry of sacral chondromyxoid fibroma.

Chondromyxoid Fibroma of the Mastoid: A Rare Entity with Comprehensive Literature Review

Chondromyxoid fibroma (CMF) is the least commonly occurring bone tumor of cartilaginous origin. It is usually situated in the metaphysis of long bones of the lower limbs. Localization of the tumor in the skull is extremely rare. The definitive diagnosis is challenging and depends on radiological and histological examinations. To the best of our knowledge, only 14 cases of CMF involving the temporal bone have been reported to date, 7 of which were within the mastoid. The most common clinical symptom is headache; however, these symptoms vary greatly according to site, size, and extension of the lesion. Surgical removal is the treatment of choice. A literature review of the diagnostic challenges, histological difficulties in differential diagnosis, imaging, clinical features, and recommended modalities of treatment have been discussed in the present case.Chondromyxoid fibroma (CMF) is the least commonly occurring bone tumor of cartilaginous origin. It is usually situated in the metaphysis of long bones of the lower limbs. Localization of the tumor in the skull is extremely rare. The definitive diagnosis is challenging and depends on radiological and histological examinations. To the best of our knowledge, only 14 cases of CMF involving the temporal bone have been reported to date, 7 of which were within the mastoid. The most common clinical symptom is headache; however, these symptoms vary greatly according to site, size, and extension of the lesion. Surgical removal is the treatment of choice. A literature review of the diagnostic challenges, histological difficulties in differential diagnosis, imaging, clinical features, and recommended modalities of treatment have been discussed in the present case.

Chondromyxoid Fibroma of Distal Phalanx of the Great Toe: A Rare Clinical Entity

Chondromyxoid fibroma is a rare benign tumor of cartilaginous origin with myxoid and fibrous components. It accounts for approximately 1% of bone tumors. Metaphysis of long bones is the most common location of this tumor. However, there a few case reports of this tumor arising from epiphysis of short tubular bones of the hand and feet.

An 11-year-old girl presented to our OPD with complaints of pain and a gradually progressive swelling of the right great toe. On examination, the swelling was diffuse with no signs of inflammation. X-ray examination revealed a well-defined, longitudinally oval lytic lesion in the right distal phalanx of great toe, involving the growth plate and, eroding the medial cortex. Computed tomography (CT) scan did not show any evidence of calcification, septations or involvement of soft tissue. Open biopsy and curettage was done and the specimen was sent for histopathological examination. Histopathological examination (HPE) showed a lobular pattern consisting of myxomatous stroma and immature cartilaginous cells in lacunae. The lobules were separated by fibrous septae. It was reported to be Chondromyxoid fibroma. The patient presented six months later with persisting pain and X-ray showed recurrence of the tumor. Hence, complete excision of the tumor was done and the defect was filled using synthetic bone graft. At six months follow up, the patient did not complain of pain and X-rays showed signs of bone formation with incorporation of the graft.

Chondromyxoid fibroma is a low grade tumor, which may demonstrate nuclear atypia histologically and mimic chondrosarcoma. Differentiating these two is of paramount importance to avoid over-diagnosis and aggressive treatment. Recurrence is common with marginal excision and especially in younger patients like in our case. Complete resection is the mainstay of management. Long-term follow up of patients is necessary to watch for malignant transformation, a rare complication. Chondromyxoid fibroma is an extremely rare neoplasm of bone. There are no specific radiologic features, and histopathology provides a definitive diagnosis. It should be considered in differential diagnosis of lytic lesion, and differentiated from other tumors, especially from chondrosarcoma to treat the patient appropriately.

Sinonasal Chondromyxoid Fibroma: Case Report and Literature Review

Chondromyxoid fibroma (CMF) is a rare, benign neoplasm of the chondroid, myxoid, and fibrous tissue. It characteristically affects the lower extremity long bones, although it may rarely arise within the craniofacial skeleton. We report the diagnosis and management of a 31-year-old male with a large, incidentally discovered CMF originating from the sphenoid sinus. A subsequent review of the literature reveals the need to differentiate from more aggressive neoplasms, such as chondrosarcoma and chondroma, which share radiographic features. A histopathologic examination is crucial for proper diagnosis and treatment. We discuss clinical sequelae, highlight the importance of a thorough pre-operative evaluation, and summarize previously suggested treatment paradigms.

Chondromyxoid Fibroma of the Pelvis: Institutional Case Series With a Focus on Distinctive Features

Chondromyxoid fibroma (CMF) is a relatively uncommon benign bone tumor of cartilaginous differentiation. The primary pitfall in the histopathologic diagnosis of CMF is confusion with a high-grade chondrosarcoma, owing to the atypical stellate and spindled cells set within a chondromyxoid background. CMF is particularly challenging to diagnose within the pelvis, where clinical suspicion for chondrosarcoma is high and benign lesions may grow to a large size to occupy the pelvic bones. In our practice, we noted this difficulty in several consecutive cases, especially when older patients presented with CMF within the pelvis. This prompted an institutional retrospective case review of all CMF within the pelvis. In 10 cases, we found overall that CMF of pelvis occurred in an older age range (mean age = 48.6 years), was larger in size (mean size = 6.0 cm), and showed a higher rate of soft tissue extension (50%) as compared with prior reports of nonpelvic CMF. Typical histologic features of CMF were seen in all cases; however, a high frequency of dystrophic calcification (50%) and necrosis (30%) was observed. Of interest, these aggregate demographic, radiologic, and histologic findings are all consistent with a benign neoplasm that has grown undetected within the pelvis over a long period of time. Recognition of these differences between pelvic CMF and tumors involving other sites will aid in avoiding misdiagnosis of this uncommon entity.

Treatment of cryotherapy and orthotopic transplantation following chondromyxoid fibroma of zygomatic bone: A case report

INTRODUCTION

Chondromyxoid fibrotherma (CMF) is a rare benign cartilage tumor that occurs more frequently in young males at the age of 20 to 30. It occurs more frequently on long bones, but rarely involves craniofacial bones.

CASE PRESENTATION

This study mainly introduced a 30-year-old male with CMF of zygomatic bone. Single tumor excochleation was conducted initially. However, CMF reoccurred, and then the following steps were adopted: firstly, the tumor was extensively excised; secondly, in vitro tumor excochleation was conducted; thirdly, the excised tumor bone was placed in liquid nitrogen for 3 cycles of cryoablation; finally, the orthotopic transplantation was performed to reconstruct the zygomatic appearance, with satisfactory follow-up efficacy obtained.

CONCLUSIONS

Orthotopic transplantation after tumorectomy and cryopreservation of tumor bone in liquid nitrogen could lead to excellent therapeutic efficacy and deserves to be widely applied in clinical practice in the treatment of a male patient with CMF of zygomatic bone, because it not only radically eliminates the tumor and kills tumor cells, but also provides bony skeleton for the growth of new bone, thus greatly promoting postoperative aesthetic degree and reducing the occurrence rates of complications.

Chondromyxoid fibroma of the distal fibula treated by percutaneous radiofrequency ablation

BACKGROUND

Percutaneous radiofrequency ablation (RFA) has been shown to be an effective treatment for soft tissue lesions and also benign bone tumors, especially osteoid osteoma. There are limited data regarding this technique in other bone tumors, specifically larger and more aggressive ones.

PURPOSES

To describe the use of RFA as a definitive treatment and an alternative to traditional open surgery for the treatment of chondromyxoid fibroma (CMF), a benign but locally aggressive bone tumor.

CASE PRESENTATION

An 11.5-year-old girl was diagnosed with a 4-cm lytic bone lesion of the distal fibula. Evaluation, including biopsy, revealed CMF. It was managed by fluoroscopy-guided RFA only. Six-year follow-up demonstrated complete healing without damage to the adjacent distal fibular growth plate.

DISCUSSION AND CONCLUSIONS

RFA induces local heat in the ablation field and causes tissue necrosis. The depth of heat penetration and the size of heated sphere are accurately controlled by modern types of ablation probes and accurate positioning. The current report demonstrates the ability to use this percutaneous technique for larger and more aggressive bone tumors than has been indicated previously.

Radiological presentation of chondromyxoid fibroma in the sellar region: A CARE-compliant article and literature review

RATIONALE

Chondromyxoid fibroma (CMF) is a rare benign bone neoplasm which often occurs in the lower extremities. Little is known about the radiological and histological presentation of CMF in the sellar region.

PATIENT CONCERNS

A 16-year-old Asian male presented to the hospital 12 months ago with bilateral diplopia involving right visual fields, intermittent headaches, and dizziness.

INTERVENTIONS

After the patient underwent enough examinations, the lesion was surgically removed by curettage.

DIAGNOSIS

Postoperatively, the lesion was pathologically confirmed to be CMF.

OUTCOMES

There was no recurrence at the 12-month follow-up.

LESSONS

To the best of our knowledge, this is the second reported case of CMF in the sellar region which was clinically suspected to be a pituitary macroadenoma, craniopharyngioma, or schwannoma due to its location and radiographic features. We reviewed the morbidity, symptoms, radiographic features, pathological findings, and differential diagnosis of CMF. Because of its rarity, attention should be paid to avoid misdiagnosis of this lesion.

[Chondromyxoid fibroma of the mandible: a case report]

Chondromyxoid fibroma (CMF) is a rare benign bone tumor. This tumor mostly affects the long bones of the appendicular skeleton but rarely grows in the craniofacial region. In this article, a case of CMF of the mandible was presented to enhance our understanding of CMF. Its clinical manifestations, imaging characteristics, and treatment methods were discussed by analyzing the related literature.

Chondromyxoid Fibroma: A Rare Case Report and Review of Literature

Chondromyxoid fibroma (CMF) is one of the rarest benign tumors of cartilaginous origin. It accounts for less than 0.5% of bone tumors and less than two percent of benign bone tumors. It is composed of a mixture of chondroid, myxoid, and fibrous tissues. The diagnosis of CMF depends upon its characteristic histological appearance like a lobular pattern with stellate-shaped cells in a myxoid or chondroid background. We present a case of juxtacortical CMF in a 15-year-old male involving the proximal end of the tibia, which was treated with en bloc excision and bone grafting with excellent results on final follow-up.

Chondromyxoid fibroma of zygoma in an elderly patient: A rare presentation

Chondromyxoid fibroma (CF) is a benign bone tumor of cartilaginous origin and is considered the least common of cartilage-derived neoplasms. The lesion's most frequent location is in long bones, while involvement of craniofacial skeleton is extremely unusual. It generally appears in the second and third decade of life and most frequent in men. We present the case of a 68-year-old female with a CF of the zygomatic region. The resection of the tumor and reconstruction of the defect is described.

Chondromyxoid fibroma of zygoma: A rare case report

Chondromyxoid fibroma (CMF) is a rare benign mesenchymal tumor of the bone. Clinically, it is characterized by a lobular growth pattern and histologically by chondroid and myxoid differentiation. The tumor is rare in the craniofacial bones with only 2% of all reported cases. Extragnathic location in the facial skeleton is extremely rare. Most of the cases reported either originate from gnathic sites or in the cranium. A case of CMF in a 3½-year-old male is presented here, which arose from the root of zygomatic arch. A detailed clinical history and histopathological picture of one more case is added to the literature. It is important to document such cases so that better light can be shed on future reviews and conclusions. This shall facilitate better treatment approaches and prognosis. This case is the first reported case of involvement of the zygomatic arch in a pediatric patient.

Chondromyxoid fibroma of the lumbar spine: case report and literature review

PURPOSE

Chondromyxoid fibroma (CMF) is a benign tumour of the bone that typically occurs in long bone metaphysis. Spinal involvement is uncommon, but more frequent in the cervical and thoracic segments. Lumbar involvement is extremely rare. We report the ninth case of lumbar CMF and the first one involving the articular process of the vertebra. A review of the literature is also intended making special emphasis on the differential diagnosis with other benign spinal tumours of the bone.

METHODS

A 21-year-old Caucasian male suffering from low back pain that increased with sports and interrupted sleep was diagnosed with a tumoural lesion in the right inferior articular process of L5.

RESULTS

Complete surgical excision of the tumour was accomplished. Histological diagnosis confirmed a CMF. The patient remains asymptomatic at 1-year follow-up.

CONCLUSION

Despite the low incidence of CMF in the lumbar spine, differential diagnosis must include this subtype of lesion among other benign tumours of the bone and cartilage. Histological diagnosis is essential in order to provide the patient with an accurate management of the pathology. Recurrence rate is to be considered even in the case of complete surgical excision. Radiotherapy administration is controversial due to suspicion of malignant transformation of the tumour.

Fine needle aspiration cytology in two cases of chondromyxoid fibroma of bone and review of literature

We report the cytological features of two cases of chondromyxoid fibroma (CMF) confirmed by histopathology examination. First case was a 40-year-old male who presented with a foot swelling, and the second case was a 16-year-old male with a lesion at the angle of jaw. A fine needle aspiration cytology (FNAC) was performed in both the cases. In first case, a correct diagnosis of CMF could be offered on FNAC. In the second case, though the cytology diagnosis was a sarcoma considering the cytological, radiological and clinical features, the histopathological examination confirmed the same to be a CMF. The cases are being discussed to highlight the usefulness of FNAC to diagnose these uncommon benign bone lesions and the potential pitfalls in the cytological diagnosis of chondroid lesions.

Cytodiagnosis of chondromyxoid fibroma

Chondromyxoid fibroma (CMF) is an unusual tumor that predominantly affects long bones of young adults. We present two cases of CMF that were diagnosed on cytology. The specific cytological features included varying combinations of chondroid, myxoid and fibroid elements. These features when correlated with clinico-radiological findings helped to arrive at a correct diagnosis. Thus a definitive diagnosis of CMF can be made on cytology based on which further line of treatment can be planned.

Aberrations of 6q13 mapped to the COL12A1 locus in chondromyxoid fibroma

Chondromyxoid fibroma, a rare benign bone tumor, may be mistaken for chondrosarcoma. Although cytogenetic studies of chondromyxoid fibroma are few, rearrangements of the long arm of chromosome 6, frequently expressed as an inv(6)(p25q13), are prominent. In this study, conventional cytogenetic analysis of 16 chondromyxoid fibroma samples from 14 patients revealed rearrangements of chromosome 6 in 10 of 11 clonally abnormal specimens. In addition to 6q13 rearrangements, recurrent 6p25 and 6q25 anomalies were detected. Notably, an identical t(6;9)(q25;q22) translocation was identified in two cases, suggesting that it represents a distinct translocation of chondromyxoid fibroma. In an effort to further define the aberrant 6q13 breakpoint and identify the molecular consequences, a fluorescence in situ hybridization (FISH)-based positional cloning strategy on chondromyxoid fibroma abnormal metaphase and interphase cells using a series of bacterial and plasmid artificial chromosome (BAC/PAC) probe combinations spanning a 6.1 Mb region was employed. The breakpoint on 6q13 was located within the COL12A1 gene, a collagen gene purportedly involved in another benign bone tumor, subungual exostosis. The findings of this study expand our knowledge of chromosomal alterations in chondromyxoid fibroma, identify COL12A1 as the likely gene candidate within the recurrent 6q13 breakpoint, and provide an alternative approach for detecting 6q13 anomalies in nondividing cells of chondromyxoid fibroma. The latter could potentially be utilized as an adjunct in diagnostically challenging cases.

Markers aiding the diagnosis of chondroid tumors: an immunohistochemical study including osteonectin, bcl-2, cox-2, actin, calponin, D2-40 (podoplanin), mdm-2, CD117 (c-kit), and YKL-40

Chondroid tumors comprise a heterogenous group of benign to overt malignant neoplasms, which may be difficult to differentiate from one another by histological examination. A group of 43 such tumors was stained with nine relevant antibodies in an attempt to find consistent marker profile(s) for the different subgroups. Archival material from three extraskeletal myxoid chondrosarcomas, five chordomas, five chondromyxoid fibromas, five chondroblastomas and 25 chondrosarcomas was stained with antibodies against osteonectin, bcl-2, cox-2, actin, calponin, D2-40 (podoplanin), mdm-2, CD117 (c-kit) and YKL-40. All 25 chondrosarcomas showed a positive staining reaction for D2-40, none for actin and CD117, and a partial reactivity for bcl-2 (36%). Chondroblastomas (5/5) and chondromyxoid fibromas (2/5) were the only tumors with a positive reaction for actin, and all chondroblastomas (n=5) and extraskeletal myxoid chondrosarcomas (n=3) were positive for bcl-2. In contrast to all other tumors, two of three extraskeletal myxoid chondrosarcomas were also positive for CD17 and negative for osteonectin, cox-2, mdm-2 and actin. All five chordomas were negative for D2-40 and positive for mdm-2 and YKL-40. The diagnosis of chondrosarcoma may be aided by its positivity for D2-40 and YKL-40 and its lack of reactivity for actin and CD117. This should be seen in the light of no reaction for D2-40 in chordomas and a corresponding lack of reaction for osteonectin, cox-2, mdm-2 and actin in extraskeletal myxoid chondrosarcomas. A convincing immunoreactivity for calponin and/or actin in chondromyxoid fibromas and chondroblastomas may also be helpful in differentiating these tumors from chondrosarcomas.

Chondromyxoid fibroma of the ala of the sacrum presenting as a cause of lumbar pain in an adolescent

We report a case of chondromyxoid fibroma of the ala of the sacrum: its presentation, diagnosis, treatment, and resolution. Although this tumor is admittedly rare, our case demonstrates the need for careful evaluation of pack pain in an adolescent.