Clonal chromosome abnormalities in a so-called Dupuytren's subungual exostosis

Identification of COL1A1/2 Mutations and Fusions With Noncoding RNA Genes in Bizarre Parosteal Osteochondromatous Proliferation (Nora Lesion)

Bizarre parosteal osteochondromatous proliferation (BPOP) (Nora lesion) is a benign bone surface lesion, which most commonly occurs in the digits of young patients and has a high rate of recurrence. Histologically, it is composed of a mixture of disorganized bone, cartilage, and spindle cells in variable proportions and characterized by amorphous "blue bone" mineralization. Recurrent chromosomal abnormalities, including t(1;17)(q32-42;q21-23) and inv(7)(q21.1-22q31.3-32), have been reported in BPOP. However, the exact genes involved in the rearrangements remain unknown. In this study, we analyzed 8 BPOP cases affecting the fingers, toe, ulna, radius, and fibula of 5 female and 3 male patients, aged 5 to 68 years. RNA sequencing of 5 cases identified genetic fusions between COL1A2 and LINC-PINT in 3 cases and COL1A1::MIR29B2CHG fusion in 1, both validated using fluorescence in situ hybridization and reverse transcription (RT)-PCR. The remaining fusion-negative case harbored 3 COL1A1 mutations as revealed by whole-exome sequencing and confirmed using Sanger sequencing. All these genetic alterations were predicted to cause frameshift and/or truncation of COL1A1/2. The chromosomal locations of COL1A2 (7q21.3), LINC-PINT (7q32.3), COL1A1 (17q21.33), and MIR29B2CHG (1q32.2) were consistent with the breakpoints identified in the previous cytogenetic studies. Subsequent screening of 3 BPOPs using fluorescence in situ hybridization identified 1 additional case each with COL1A1 or COL1A2 rearrangement. Our findings are consistent with reported chromosomal abnormalities and implicate the disruption of type I collagen, and perhaps of either noncoding RNA gene as a tumor suppressor, in the tumorigenesis of BPOP. The prevalence and tumorigenic mechanisms of these COL1A1/2 alterations in BPOP require further investigation.

Some Reactive Lesions of Bone Are Probably Neoplasms: A Review

CONTEXT.—

A number of fibro-osseous and osteocartilaginous lesions, especially common in the small bones of hand and feet, pose a diagnostic challenge and have historically been thought to be reactive lesions. However, modern molecular techniques when supplementing clinical, radiographic, and histologic evaluation suggest they may, in fact, be neoplasms.

OBJECTIVE.—

To review the clinical presentation and histopathologic, molecular, and radiologic features of selective bone lesions, focusing most specifically on subungual exostosis, florid reactive periostitis, and bizarre periosteal osteochondromatous proliferation.

DATA SOURCES.—

Literature review and personal experience are the source of this review.

CONCLUSIONS.—

Some lesions previously thought to be reactive are locally aggressive and demonstrate reproducible molecular abnormalities, and thus may be neoplasms. Although most common in the bones of the fingers and toes, these lesions also occur in long and other bones. The clinical presentations, radiologic appearances, and histopathologic features often overlap, making the diagnosis challenging, and these lesions may require molecular evaluation to maximize accurate prognostication.

Subungual exostosis - treatment results with preservation of the nail bed

Subungual exostosis is a rare benign osteocartilaginous tumor, of unknown etiology, that affects the subungual part of the distal phalanx and predominantly affects adolescent females. The objective of this study is to evaluate the results of surgical treatment of subungual exostosis in pediatric patients by means of surgical excision and nail preservation. We present a retrospective study, including pediatric patients with subungual exostosis who underwent surgical treatment in a single institution, over a 6-year period, We describe the surgical technique used, the characteristics of the patients and lesions, and evaluate the results obtained in terms of function, satisfaction and complications. Thirteen patients were included in this study, seven female (54%) and six male (46%), median age 11 years old. The most common location was the hallux, in eight patients (73%). Patients had good functional results with a median American Orthopedic Foot & Ankle Society score of 100 [80; 100] and a median personal satisfaction score of 9. The median follow-up was 30 [3;68] months. In our patients, subungual excision with nail bed preservation, allows a good balance between the radical excision of the exostosis and the preservation of the natural protection granted by the native nail, yielding good functional results and patient satisfaction.

Subungual Exostosis Systematic Review and Meta-Analysis

BACKGROUND

The coexistence of deformity of the nail bed and subungual exostosis (SE) is a frequent finding in podiatric practice in the fourth and fifth decades of life. However, it has been described by other specialists as being an uncommon osteocartilaginous tumor most prevalent during the second and third decades of life. This study attempts to determine the causes of this discrepancy.

METHODS

Two authors independently conducted a systematic bibliographic review in multiple databases, podiatry sources and others, and key words were chosen to achieve a broad search strategy. Studies reporting on epidemiology and treatment of SE lesions in lower extremities in ten or more patients were selected. Initially, 197 articles were identified through database screening, with 23 meeting all inclusion and exclusion criteria. Seven articles with the ages of all of the patients were included in the analysis of age data. A comparison was then made between the diagnostic criteria for the selected 23 articles.

RESULTS

Model results reveal that, although there are some significant differences between individual studies, the main factor tested (patient's age) was clearly significant ( F_1,5.2 = 78.12, P < .001), showing that studies coming from the podiatry speciality were conducted on individuals with a mean age of 37 years higher than in studies from other specialties. Clinical and radiologic characteristics and treatment described in the podiatry literature also contrast with those in other specialties.

CONCLUSIONS

The SE described by podiatrists, in accordance with the parameters of true exostosis, is different from Dupuytren's SE and should be considered as a different pathologic entity. The authors are working on its histologic identification.

Conditions Simulating Primary Bone Neoplasms

A number of nonneoplastic conditions can mimic tumors of bone. Some of the more common mimics of primary bone tumors include infectious, inflammatory, periosteal, and degenerative joint disease-associated lesions that produce tumorlike bone surface-based or intraosseous lesions. This article considers a spectrum of reactive and nonreactive processes including stress fracture, subchondral cysts, osteonecrosis, heterotopic ossification, osteomyelitis, sarcoidosis, and amyloidoma that can present in such a way that they are mistaken for a tumor arising primary in bone.

Subungual exostosis of the toes: a systematic review

BACKGROUND

Subungual exostosis is a relatively common benign bone tumor that occurs in the distal phalanges of the toes and can be a source of pain and nail deformity. There is controversy about the treatment of these lesions and there are few studies that have synthesized what is known and provided meaningful information on treatment.

QUESTIONS/PURPOSES

We performed a systematic review to address the following questions: (1) What is the best surgical approach for excising these lesions? (2) What is the age range, sex distribution, and presenting symptoms of subungual exostoses and which toe is most frequently affected? (3) What complications arise from treatment?

METHODS

Two authors independently searched multiple databases (Medline, 1950-May 2013; Cochrane EBM database, and EMBASE, 1980-May 2013 provided by OVID; ACP Journal Club, 2003-May 2013; CINAHL by EBSCO, 1937-May 2013; and PubMed by NLM, 1940-May 2013), and key words were chosen to achieve a broad search strategy. We included studies on the management of toe exostoses with > 10 cases and we excluded studies that reported on upper extremity exostoses or osteochondromas. Demographic and treatment data were collected from each article by two independent authors and collated. A total of 124 abstracts were screened, and 116 articles were reviewed in full, of which 13 met the inclusion criteria.

RESULTS

Complete marginal excision through a fish mouth incision protecting the nail led to a recurrence rate of 4% and satisfactory clinical results, defined as no requirement for postoperative intervention and a satisfactory clinical appearance in 73%. Most studies provided incomplete descriptions of specific surgical techniques used. Fifty-five percent of the patients were younger than 18 years of age. A history of toe trauma before diagnosis was present in approximately 30% of the cases. Delayed diagnosis occurred in approximately 10% of the cases and onychodystrophy occurred in more than 10%.

CONCLUSIONS

There is weak evidence to guide management of subungual exostosis. Adequate wound management postexcision aiming to minimize disruption to the nail bed and matrix may prevent onychodystrophy, which is a common complication of treatment.

Advances in the identification of molecular markers for bone neoplasia

IMPORTANCE OF THE FIELD

Bone tumors represent a heterogeneous and poorly understood group of neoplasms affecting patients of all ages. This review is intended to highlight recent advances in the identification of diagnostically relevant molecular biomarkers.

AREAS COVERED IN THIS REVIEW

This review offers a summary of basic techniques in molecular pathology. In the case of primary bone tumors with diagnostically applicable molecular markers, an overview of the tumor is provided incorporating the germane background and advances in the identification of molecular markers.

WHAT THE READER WILL GAIN

The reader will gain an understanding of the techniques governing the discovery of biomarkers, and their applicability in diagnostic bone pathology.

TAKE HOME MESSAGE

Molecular analysis has identified key diagnostic biomarkers in only a small proportion of bone tumors. Many of these findings owe their existence to earlier karyotype-based cytogenetic studies. In cases where characteristic cytogenetic findings are absent, there remains a tremendous need to interrogate rigorously these lesions using emerging techniques such as whole genome sequencing. It is assumed that with a more precise understanding of the tumor genetic code, more accurate diagnostic, prognostic and therapeutic markers will emerge.

No gene copy number changes in Dupuytren's contracture by array comparative genomic hybridization

Dupuytren's contracture (DC), a benign disease of unknown origin, is characterized by abnormal fibroblast proliferation and matrix deposition within the palmar and plantar faciae, causing contracture of the digits. Conventional cytogenetic studies of cultured fibroblast cells from DC nodules have revealed nonrecurrent, but usually normal, clonal (mainly +7, +8, and -Y, plus structural changes) and sporadic (nonclonal) numerical/structural rearrangements. No unique cytogenetic features of DC are known so far. We used 44K oligonucleotide-based array comparative genomic hybridization to obtain a wide pattern of chromosomal imbalances in 18 patients with DC. The genome-wide analysis revealed no changes of DNA copy number sequences. Accordingly, gene amplifications or deletions are apparently not involved in the progression of abnormal fibroblast proliferation and matrix deposition that lead to DC.

50 years experience with Dupuytren's contracture in the Erlangen University Hospital--a retrospective analysis of 2919 operated hands from 1956 to 2006

Background

Dupuytren's disease (DD) is a hand disorder mainly among the northern population. In contrast it is rare in the mediterranean population. Therefore typical habits and dietetic influences have been discussed as well as genetic predisposition. Still, since the first description by Dupuytren in 1834 only little is known about the etiology and pathogenesis of this disease. Some hints were found for a higher prevalence among people with diabetes, alcohol abuse or smoking. Also, intensive manual work or hand injuries have been discussed to have an influence on DD. To our knowledge this is the largest retrospectively evaluated series of symptomatic patients published to date. The study includes patients from the last 50 years. It was performed to show possible correlations between DD and typical risk factors such as diabetes, alcohol consumption, and smoking.

Methods

We retrospectively analysed all patient records with DD documented between 1956 and 2006 in the Surgical University Hospital in Erlangen. Data acquisition was conducted by reviewing the medical records from 1956 to 2006 including data from all patients who were surgically treated because of DD.

Results

We reviewed 2579 male and 340 female surgically treated patients with DD. More than 80% of the patients were between 40 and 70 years old. In 28.9% only the right hand was effected by DD, in 25.3% only the left hand and in 45.8% both hands. In 10.3% of all Patients suffered from Diabetes mellitus. Statistical analysis revealed no significant correlation between diabetes, alcoholism or smoking on the degree of DD in our patients.

Conclusion

Most data are consistent with previously published results from smaller, comparable retrospective studies with regard to right- or left handedness. We could not confirm a statistically significant correlation of DD with diabetes mellitus, severe alcohol consumption, heavy smoking or epilepsy and the stage of the disease as described in other studies. However, in the whole cohort of our operated patients during the last 50 years the prevalence of the above mentioned risk factors is slightly higher than in the normal population.

Rearrangement of the COL12A1 and COL4A5 genes in subungual exostosis: molecular cytogenetic delineation of the tumor-specific translocation t(X;6)(q13-14;q22)

Subungual exostosis is a benign bone- and cartilage-producing tumor occurring in the hands and feet of children and young adults. The recent identification of a recurrent chromosomal translocation t(X;6)(q24-q26;q15-21) in short-term-cultured tumor cells strongly suggests that subungual exostosis is a neoplastic lesion caused by rearrangement of genes in the two breakpoints. To identify the genes that are critical for neoplastic transformation, we have studied five subungual exostoses by interphase or metaphase FISH. The results of these analyses demonstrated a clustering of the breakpoints to the regions harboring the collagen genes COL12A1 and COL4A5 in chromosome bands 6q13-14 and Xq22, respectively. Furthermore, in all but one case, these two genes were shown to colocalize on the derivative chromosomes X and 6, strongly suggesting that at least one of them is consistently involved in the formation of a chimeric fusion gene or in the exchange of regulatory sequences. Because collagen molecules are important for tissue remodeling during physiologic growth and differentiation, both COL12A1 and COL4A5 constitute good candidate target genes in the pathogenesis of subungual exostosis. Further investigations on the transcript level are required to elucidate the functional outcome of the t(X;6) translocation in subungual exostoses.

Bizarre parosteal osteochondromatous proliferation with a t(1;17) translocation

Bizarre parosteal osteochondromatous proliferation (BPOP) is a benign lesion that tends to recur repeatedly. Histologically, BPOP contains three components (cartilage, bone, and spindle cells) in differing amounts. The histological findings of BPOP are similar to those of florid reactive periostitis (FRP) and subungual (Dupuytren's) exostosis. Some authors have postulated that all of these conditions are reactive proliferative lesions representing different phases of reactive processes. Whether BPOP is a reactive proliferative lesion or a neoplastic lesion, however, remains controversial. Recently, a t(1;17)(q32;q21) translocation in BPOP was detected using chromosome banding and fluorescence in situ hybridization (FISH) analyses. Here, we describe a 39-year-old Japanese female with BPOP arising in the proximal phalanx of her third toe. A cytogenetic analysis revealed a t(1;17)(q 42;q23) translocation. The breakpoints in this case are located close to those of previously reported cases. These results suggest that t(1;17) is a distinct translocation of BPOP and that BPOP is a neoplastic lesion, rather than a reactive proliferative process.

Distinct Chromosomal Rearrangements in Subungual (Dupuytren) Exostosis and Bizarre Parosteal Osteochondromatous Proliferation (Nora Lesion)

BACKGROUND

Proliferative lesions of the bone surface, such as subungual (Dupuytren) exostosis and bizarre parosteal osteochondromatous proliferation (BPOP, Nora lesion) are currently classified as reactive, proliferative processes that mimic primary neoplasms of bone.

METHODS

Cytogenetic analysis was performed on 3 subungual exostoses of the great toe and 2 BPOP lesions of the radius and ulna.

RESULTS

A balanced translocation t(X;6) was identified in all cases of subungual exostoses. The chromosomal rearrangements observed in 1 case of BPOP differed from those seen in subungual exostosis.

CONCLUSIONS

The presence of chromosomal abnormalities in subungual exostosis and BPOP suggests that these lesions are neoplastic, with a different molecular pathogenesis, and that each is a distinct clinicopathologic entity.

Subungual Osteochondroma: Clinical and Radiologic Features and Treatment

BACKGROUND

Subungual osteochondromas are relatively rare.

OBJECTIVE

The objective was to evaluate the clinical, histologic, radiologic, and therapeutic features of subungual osteochondroma.

METHODS

We retrospectively analyzed 27 cases of subungual osteochondroma evaluating the clinical manifestations, the radiologic and histologic features, and the treatment.

RESULTS

There were 20 females and 7 males. The first toe was the most commonly involved. Previous trauma was recalled in 40.7% of the cases. Subungual osteochondromas appeared as firm, exophytic tumors beneath the ungual plate. Twenty-five patients had pain. The radiologic films demonstrated the presence of a juxtaephiphyseal radiodense cap surrounded in some cases by cortical bone. A Dubois-like excision was performed to expose the tumor and cut it through the base, followed by curettage of the bony bed. Radiologic controls were taken 30 and 60 days after surgery and in cases of symptomatology. There were three cases of recurrence and two cases of incomplete excision.

CONCLUSIONS

Subungual osteochondroma should be distinguished from other subungual masses. The diagnosis of subungual osteochondroma is clinicoradiologic.

Recurring breakpoints of 1p13 approximately p22 in osteochondroma

Cytogenetic studies of osteochondromas are scarce but have previously shown recurring clonal aberrations involving chromosome 8. We have studied a series of eight tumors and have found recurring aberrations not only involving chromosome 8, but also chromosome 1 in five of the seven abnormal tumors. Surprisingly, three of the chromosome 1 aberrations involved pericentric inversions. Four tumors showed aberrations involving the region 1p13 approximately p22 by mechanisms including inversion, insertion, and translocation. These findings indicate that aberrations of chromosome 1p, in a region spanning 1p13 approximately p22, may be nonrandomly involved in the cytogenetic progression of osteochondroma.