Cytogenetic analysis of a scapular chondromyxoid fibroma

Differential Diagnosis of Cartilaginous Lesions of Bone

CONTEXT.—

Cartilaginous tumors represent one of the most common tumors of bone. Management of these tumors includes observation, curettage, and surgical excision or resection, depending on their locations and whether they are benign or malignant. They can be diagnostically challenging, particularly in small biopsies. In rare cases, benign tumors may undergo malignant transformation.

OBJECTIVE.—

To review common cartilaginous tumors, including in patients with multiple hereditary exostosis, Ollier disease, and Maffucci syndrome, and to discuss problems in the interpretation of well-differentiated cartilaginous neoplasms of bone. Additionally, the concept of atypical cartilaginous tumor/chondrosarcoma grade 1 will be discussed and its use clarified.

DATA SOURCES.—

PubMed (US National Library of Medicine, Bethesda, Maryland) literature review, case review of archival cases at the Massachusetts General Hospital, and personal experience of the authors.

CONCLUSIONS.—

This review has examined primary well-differentiated cartilaginous lesions of bone, including their differential diagnosis and approach to management. Because of the frequent overlap in histologic features, particularly between low-grade chondrosarcoma and enchondroma, evaluation of well-differentiated cartilaginous lesions should be undertaken in conjunction with thorough review of the imaging studies.

A case report on partial scapulectomy with glenoid preservation for Chondromyxoid fibroma of scapula

Chondromyxoid fibroma is a benign bone tumour accounting for less than 1% of all primary bone tumours. It usually affects the metaphyseal region of long bones in the first or second decade of life. It rarely occurs in scapula. We present a case of 29 year old female with biopsy proven Chondromyxoid fibroma of left scapula. She underwent wide marginal excision by partial scapulectomy with preservation of glenoid. Post operatively she has stable shoulder joint with normal range of movement & no recurrence on regular follow up.

Chondromyxoid Fibroma of the Skull Base and Calvarium: Surgical Management and Literature Review

Chondromyxoid fibroma (CMF) is an exceedingly rare tumor that represents less than 1% of all primary bone neoplasms. Occurrence in the facial and cranial bones is extremely rare and frequently misdiagnosed.

Case Reports We report two cases of CMF, one in the sphenoclival skull base and the other involving the parietal bone in two young female patients. Excision was performed in both cases. Presenting symptoms, treatment, and follow-up are reported.

Methods A retrospective review of the literature on cranial CMF was performed. The location, demographics, presenting symptoms, and treatment of all calvarial and skull base CMF cases published since 1990 are summarized.

Discussion In our literature review, we found 67 published cases of cranial CMF. Mean age of all calvarial and skull base CMFs at diagnosis was 38.2 years old. Of the cases affecting the cranium, the sinonasal structures were most commonly involved. To our knowledge we report only the second case of CMF involving the parietal bone published in an English-language journal. Total resection is the best treatment, and should be the goal of surgical intervention. Curettage results in high recurrence rates. Radiotherapy in the setting of subtotal resection or recurrence cannot be definitively recommended and needs further investigation.

A t(1;9)(q10;q10) translocation with additional 6q23 and 9q22 rearrangements in a case of chondromyxoid fibroma

Chondromyxoid fibroma (CMF) is a rare cartilaginous tumor of bone. It typically presents in the long tubular bones and to a lesser extent in the small bones of the hands and feet of young adults. To date, several cytogenetic abnormalities have been described in association with CMF. We studied a phalangeal CMF from a 13-year-old female by cytogenetic methods. We found a novel unbalanced translocation between the long arms of chromosomes 1 and 9, resulting in loss of 1p. In addition, rearrangements involving the 6q23 and 9q22 regions were also observed. To our knowledge, this is the first report in the literature describing this novel chromosomal translocation in CMF.

Temporal Chondroblastoma with a Novel Chromosomal Translocation (2;5) (q33;q13)

The case of a 51-year-old man with a large temporal mass is presented. The mass eroded the floor of the middle fossa medially to the sphenoid sinus. A combined approach with neurosurgery and otolaryngology was performed to achieve maximal resection of the mass. Pathology was typical for chondroblastoma: a rare, benign but locally invasive chondroid tumor. Genetic testing revealed a translocation of (2;5) (q33;q13). This is a unique genetic mutation in all chondroid tumors to our knowledge. The diagnostic utility or role of this mutation in the pathobiology of this tumor remains to be determined.

Clonal complex chromosome aberration in non-ossifying fibroma

Cytogenetic information of non-ossifying fibromas (NOFs) is exceptionally limited. This fact relies, in part, on their benign nature but mainly because most cases evolve undetected or there is no need for surgical intervention. We report the case of a NOF arising in the left tibia of a 14-year-old male with an invariable clonal translocation. The karyotype was denoted as 42-46,XY,t(11;3;14)(q23;p21;p11). There are only two previous reported cases of clonally aberrant NOF. Records from additional cases will be essential to assess whether consistent karyotypic aberrations define this lesion.

Genome-wide analyses of gene expression during mouse endochondral ossification

Background

Endochondral ossification is a complex process involving a series of events that are initiated by the establishment of a chondrogenic template and culminate in its replacement through the coordinated activity of osteoblasts, osteoclasts and endothelial cells. Comprehensive analyses of in vivo gene expression profiles during these processes are essential to obtain a complete understanding of the regulatory mechanisms involved.

Methodology/Principal Findings

To address these issues, we completed a microarray screen of three zones derived from manually segmented embryonic mouse tibiae. Classification of genes differentially expressed between each respective zone, functional categorization as well as characterization of gene expression patterns, cytogenetic loci, signaling pathways and functional motifs both confirmed reported data and provided novel insights into endochondral ossification. Parallel comparisons of the microdissected tibiae data set with our previously completed micromass culture screen further corroborated the suitability of micromass cultures for modeling gene expression in chondrocyte development. The micromass culture system demonstrated striking similarities to the in vivo microdissected tibiae screen; however, the micromass system was unable to accurately distinguish gene expression differences in the hypertrophic and mineralized zones of the tibia.

Conclusions/Significance

These studies allow us to better understand gene expression patterns in the growth plate and endochondral bones and provide an important technical resource for comparison of gene expression in diseased or experimentally-manipulated cartilages. Ultimately, this work will help to define the genomic context in which genes are expressed in long bones and to understand physiological and pathological ossification.

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.

Juvenile juxtacortical chondromyxoid fibroma of bone: a case report

Conventional intramedullary chondromyxoid fibroma (CMF) is a rare benign tumor of bone; juxtacortical lesions are rarer still, and juxtacortical lesions occurring in children are heretofore essentially unreported. We present a case of such a lesion in a 12-year-old boy. This patient, who was previously healthy, presented with a 1-week history of poorly defined pain and mild swelling in the region of the left proximal tibia. Magnetic resonance imaging and bone scan showed changes most consistent with an aggressive biological process. However, the permanent histologic sections showed a (pseudo) lobular pattern of spindle cells with minimal pleomorphism and other features consistent with CMF. A clonal abnormality was detected in 15% of tumor cells karyotyped, characterized by a break in the long arm of chromosome 6 and a balanced Robertsonian translocation involving chromosomes 14 and 21. The patient has remained well and free of recurrence for more than 4 years. In general, CMF needs to be distinguished from its mimicker low-grade chondrosarcoma, and it must be recognized as occurring on bone surfaces among a wide age range of individuals. Juxtacortical CMF has not proven to be unusually aggressive in adults nor in this child, and marginal (en-block) resection remains the treatment of choice.

Chondromyxoid fibroma of rib with a novel chromosomal translocation: a report of four additional cases at unusual sites

BACKGROUND

Chondromyxoid fibromas (CMFs) are rare benign chondroid/myxoid matrix-producing tumors that occur in metaphyses of long tubular bones, and very rarely in small bones of hands and feet. Flat bone involvement is even more uncommon. Prior cytogenetic analyses have identified complex abnormalities involving chromosome 6 in the majority of cases.

METHODS

A search for CMF over an 8-year period (1999-2006) from the surgical pathology files of our institution yielded 16 cases. Four cases occurred in relatively unusual regions, three from the small bones of distal extremities and one from the rib. The rib lesion was submitted for routine cytogenetic analysis.

RESULTS

Radiographic studies revealed that all four lesions were well-defined expansile radiolucent lesions which expanded the bony cortices with lobulated margins, sclerotic rim, septation, and no calcification. Morphologically, all four lesions showed typical features of CMF and had low proliferative index with Ki-67. Cytogenetic analysis on the rib lesion revealed a novel chromosomal translocation, t(1;5)(p13;p13). None of the four patients had a recurrence after a mean duration of follow-up of 24 months.

CONCLUSION

CMF originating in unusual locations should be distinguished from chondrosarcomas, especially on small biopsies, and should be included in the differential diagnosis. As previously noted in the literature, the cells can be positive for actin but unlike conventional chondroid neoplasms can be negative for S-100. To our knowledge, this is the first report describing a novel chromosomal translocation, t(1;5)(p13;p13) in CMF.

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.

Chondromyxoid fibroma of the nasal cavity with an interstitial insertion between chromosomes 6 and 19

Chondromyxoid fibroma is an uncommon benign cartilaginous tumor that rarely presents in the sino-nasal region as a locally destructive, erosive lesion. Both clinically and histologically, it is a difficult diagnosis and can be confused with malignant processes such as myxoid chondrosarcoma. Histology of the tumor, especially with a small sample, can be challenging because of its heterogeneous nature showing an admixture of fibrous, myxoid, and chondroid areas. We are reporting unique cytogenetic findings in a case of chondromyxoid fibroma involving the floor of the nasal cavity with a clonal rearrangement between chromosomes 6 and 19. To our knowledge, karyotypes of 14 cases are reported in literature, with 11 cases reporting nonrandom, clonal abnormalities of chromosome 6. These results illustrate the distinctive nature of this tumor and may help identify genes involved in the pathogenesis of this tumor.

Molecular pathology of chondroid neoplasms: part 1, benign lesions

This two-part review presents an overview of the molecular findings associated with both benign and malignant chondroid neoplasms. This first part presents a brief review of methods in molecular pathology along with a review of the cytogenetic and molecular genetic findings in benign chondroid neoplasms. Clinical aspects of the various lesions are briefly discussed, and each tumor is illustrated with representative radiographic and pathologic images. Malignant chondroid neoplasms will be considered in the second part of this review.

Chondromyxoid fibroma: a rarely encountered and puzzling tumor

Chondromyxoid fibroma is an uncommon bone neoplasm, accounting in our series for less than 1% of all connective tissue tumors. The tumor is more common in males, and located mostly in the metaphyseal areas of the lower extremity. The tumor is benign and there have been no reports of metastases. The method of treatment that has been used since the initial identification of the tumor has been curettage, which has a 20-25% recurrence rate. In our 30 patients, the average length of followup was 11 years (range, 1-29 years. Most of the tumors were in the pelvis, proximal tibia, distal femur, and foot. Tumors that were treated with curettage alone did less well than those that were packed with allograft bone or polymethylmethacrylate. Tumors treated by excision did not recur. The most difficult problem with chondromyxoid fibroma is pathologic identity because it often is confused with more aggressive tumors that may metastasize.

Parathyroid hormone-related Peptide expression in cartilaginous tumors

Parathyroid hormone-related peptide is one of the most important regulators of chondrocyte proliferation. Although cartilaginous neoplasms express different collagens, including Types II and X, the pathogenesis of these tumors has not been elucidated. The current study examined the hypothesis that parathyroid hormone-related peptide is expressed in cartilaginous neoplasms and its level of expression may correlate with the proliferative rate of cartilaginous neoplasms with higher levels in more malignant tumors and lower levels in benign lesions. Two hundred thirty-four biopsy and resection specimens of benign and malignant cartilage tumors from 179 patients were retrieved from surgical pathology archival material and analyzed immunohistochemically using an antibody to human parathyroid hormone-related peptide. Most cartilaginous neoplasms had some level of expression of parathyroid hormone-related peptide, and tumors with a more proliferative phenotype had higher levels of parathyroid hormone-related peptide. Although benign lesions such as enchondromas and osteochondromas had low levels of parathyroid hormone-related peptide, malignant neoplasms such as extraskeletal myxoid chondrosarcomas, dedifferentiated chondrosarcomas, and mesenchymal chondrosarcomas expressed high levels of parathyroid hormone-related peptide. Parathyroid hormone-related peptide expression correlated with grade of malignancy in chondrosarcoma. Although there were highly significant differences between Grade I chondrosarcoma versus Grade II and Grade III lesions, the difference between Grade II and Grade III chondrosarcomas approached significance. Parathyroid hormone-related peptide may represent a new tumor marker with potential diagnostic use in classifying cartilaginous neoplasms.

Ossifying fibromyxoid tumor of soft parts: report of a case with novel cytogenetic findings

A slowly growing tumor of the left thenar region in a 40-year-old man had the classic features of an ossifying fibromyxoid tumor of soft parts, including an incomplete shell of lamellar bone; a center composed of nodular aggregates of small spindled, oval, and stellate cells in abundant myxoid stroma; and strong expression of vimentin, S-100, and neuron-specific enolase by the tumor cells. Clonal chromosomal abnormalities included loss of a chromosome 6, extra material of unknown origin attached to the long arm of chromosome 12, and an unbalanced translocation involving the short arm of a chromosome 6 and the long arm of a chromosome 14. The karyotype was interpreted as 45,XY, der(6;14)(p10;q10),add(12)(q24.3). The chromosomal abnormalities suggest osteochondroblastic rather than neuronal or schwannian lineage.

Osteoid osteomas with chromosome alterations involving 22q

Cytogenetic analysis was performed in two osteoid osteomas. In both, the modal chromosome number was 46. One of the cases presented a del(22)(q13.1) as the sole clonal chromosome alteration. The other had clonal monosomies of chromosomes 3, 6, 9, 17, 19, and 21, as well as a +del(22)(q13.1) was detected as a non-clonal chromosome alteration. There is only one osteoid osteoma reported so far showing clonal karyotypic alterations. The cytogenetic behavior of osteoid osteomas described here was different from that of the osteoid osteoma of the literature. Numerical alterations of chromosomes 3, 6, 9, 17, 19, 21 and 22 have been described in several neoplasias including bone tumors. The breakpoint of chromosome 22 involves a region where important genes for the regulation of the cell cycle have been mapped.

Murine Bv8 gene maps near a synteny breakpoint of mouse chromosome 6 and human 3p21

The genomic structure of the murine Bv8 gene was determined in 129/SvJ mouse, and the chromosomal localization was identified. Bv8 has first been characterized from skin secretion of the yellow-bellied toad, Bombina variegata. When injected into rat brain, this polypetide causes hyperalgesia. The murine Bv8 gene was shown to consist of four exons and was localized on chromosome 6 between the microsatellite markers D6Mit66 and D6Mit36 near the gene mem1, whereas the human counterpart was assigned to the non-syntenic region 3p21.1. Furthermore, the primary Bv8 transcript appeared to be alternatively spliced. The first variant contained all four exons yielding a product with a stretch highly enriched in basic amino acids in its central part. This domain is absent in the peptides from frog as well as in a splice variant expressed in mouse testis. A third variant gives rise to a truncated polypeptide.