Structural chromosome aberrations in an adamantinoma

Unraveling molecular signatures in rare bone tumors and navigating the cancer pathway landscapes for targeted therapeutics

Rare cancers (RCs), which account for over 20% of cancer cases, face significant research and treatment challenges due to their limited prevalence. This results in suboptimal outcomes compared to more common malignancies. Rare bone tumors (RBTs) constitute 5-10% of rare cancer cases and pose unique diagnostic complexities. The therapeutic potential of anti-cancer drugs for RBTs remains largely unexplored. Identifying molecular alterations in cancer-related genes and their associated pathways is essential for precision medicine in RBTs. Small molecule inhibitors and monoclonal antibodies targeting specific RBT-associated proteins show promise. Ongoing clinical trials aim to define RBT biomarkers, subtypes, and optimal treatment contexts, including combination therapies and immunotherapeutic agents. This review addresses the challenges in diagnosing, treating, and studying RBTs, shedding light on the current state of RBT biomarkers, potential therapeutic targets, and promising inhibitors. Rare cancers demand attention and innovative solutions to improve clinical outcomes.

Osteofibrous dysplasia and adamantinoma: A summary of diagnostic challenges and surgical techniques

Osteofibrous dysplasia is an indolent benign fibro-osseous tumor, while adamantinoma is a locally aggressive biphasic malignancy with epithelial and fibro-osseous components. Predominantly arising in the tibial diaphysis of children and young adults, both tumors are resistant to chemotherapy and radiation. Wide surgical resection is regarded as the mainstay of therapy for adamantinoma, and limb-salvage reconstructive procedures can achieve good functional outcomes, albeit with non-negligible rates of complications. This review discusses emerging advances in the pathogenesis, histogenesis, and diagnosis of these entities and presents advantages and limitations of the most common surgical techniques used for their management.

Clonality assessment in a case of multifocal adamantinoma and a review of the literature

Adamantinoma is a low-grade, malignant biphasic bone tumour predominantly located in the tibia. In up to 50% of all cases this is combined with one or more lesions in the ipsilateral fibula. Whether these lesions represent regional metastases or arise de novo is not yet exactly known. In order to address this question, we extracted DNA from the respective fresh frozen tumour tissues in a case of a young woman with a multifocal adamantinoma of both the tibia and ipsilateral fibula. Afterwards the X inactivation pattern was studied by means of methylation-sensitive polymerase chain reaction and primers that target the polymorphic CGG trinucleotide repeat of FMR1 gene and the polymorphic CAG repeat, on exon 1 of the human androgen receptor gene (AR). The analysis of the AR was homozygous and not informative. Studying the FMR1 gene, we detected a 100% skewing of the X inactivation pattern of both locations and found that the same allele was methylated. Even if the fibula lesion arose de novo there would have been a 50 : 50 chance that the same allele was methylated. As this methylation pattern was found we cannot provide a valid explanation for the origin of the fibula lesion. Analysis of X inactivation patterns in future cases of polyfocal adamantinoma might provide further evidence for one of the two theories.

Adamantinoma with plasmacytoid features: expanding the spectrum of a diagnostically challenging entity

Adamantinoma is a rare neoplasm that characteristically involves the tibia. In many instances, typical location within the tibia, very slow course, and a typical radiographic appearance can strongly suggest the correct diagnosis. We present a case that has both unusual radiographic findings and uncharacteristic histology. In this case, radiologic imaging showed a poorly defined lytic lesion within the distal, lateral tibia extending to the joint with central necrosis, overlying periosteal reaction and possible tumor spread into soft tissue. The histology of this lesion showed pronounced vascularity and surrounding large neoplastic cells with plasmacytoid morphology. The combination of these features led to an initial misdiagnosis as metastatic carcinoma from unknown primary.

Osteofibrous dysplasia and adamantinoma in children and adolescents: a clinicopathologic reappraisal

Osteofibrous dysplasia (OFD) and adamantinoma are rare and most commonly arise in the tibia of young individuals. Although OFD has typical histopathologic features, areas resembling OFD have often been noted at the periphery of otherwise classic adamantinomas, and some have suggested that OFD may be either a precursor to or a regressive phase of adamantinoma. The so-called OFD-like adamantinoma encompasses some features of both OFD and adamantinoma. We studied the clinical, imaging, histopathologic, immunohistochemical, ultrastructural, and molecular features of 16 OFD and 8 adamantinomas (5 OFD-like and 3 classic) in an attempt to further define their morphology, clinical course, and relationship. Patients with OFD were generally younger than those with adamantinoma. Osteoblastic and osteoclastic activity was more prominent in OFD than in OFD-like adamantinoma. In addition to the inconspicuous small clusters of epithelial cells in OFD-like adamantinoma, isolated keratin-positive cells with a unique ultrastructural hybrid fibroblastic-epithelial phenotype were found in the stroma of all OFD and OFD-like adamantinomas. Fluorescence in situ hybridization analysis revealed trisomies 7, 8, and/or 12 in the spindle cell stroma of OFD, OFD-like, and classic adamantinoma, supporting a neoplastic origin of OFD and a common histogenesis for all 3 lesions. Trisomies were not observed in osteoblasts or osteoclasts suggesting that the osseous component is reactive and non-neoplastic. Of the 11 OFD patients with follow-up (median, 4.5 y), all 3 who underwent incisional biopsy had persistent, nonprogressive disease and 2 of 8 who underwent curettage or wide excision had recurrence; none developed adamantinoma. All 6 adamantinoma patients with follow-up (3 classic and 3 OFD-like) were treated with wide excision. One with classic adamantinoma died of pulmonary metastases 9 years after presentation; the other 5 were free of disease with a median follow-up of 12 years. None of the classic adamantinomas evolved into OFD-like adamantinoma or OFD. Although the histopathology, immunohistochemistry, ultrastructure, and cytogenetics indicate that these lesions are closely related, our data and the literature suggest that only classic adamantinoma has malignant potential. OFD, OFD-like adamantinoma, and classic adamantinoma appear to show a progressive complexity of cytogenetic aberrations, perhaps indicative of a multistep neoplastic transformation.

Adamantinoma: a clinicopathological review and update

Adamantinoma is a primary low-grade, malignant bone tumor that is predominantly located in the mid-portion of the tibia. The etiology of the tumor is still a matter of debate. The initial symptoms of adamantinoma are often indolent and nonspecific and depend on location and extent of the disease. Histologically, classic adamantinoma is a biphasic tumor characterized by epithelial and osteofibrous components that may be intermingled with each other in various proportions and differentiating patterns. To assure the histological diagnosis, pathologists should employ immunohistochemistry for demonstrating the sometimes sparse epithelial cell nests when the radiological features are suggestive of adamantinoma. There is paucity of compiled data over adamantinoma in the literature, hence authors tried to make a comprehensive review which must be of use to beginners and trained pathologists. Our objective is to further define the clinicoradiologic features and pathologic spectra of adamantinoma.

Adamantinoma in childhood: report of six cases and review of the literature

BACKGROUND

Adamantinoma is a rare slow-growing malignant bone tumour.

OBJECTIVE

To describe the imaging appearances of six childhood cases and review the published literature.

MATERIALS AND METHODS

The database of the Working Group on Paediatric Oncology, Academic Medical Centre/Emma Children's Hospital Amsterdam, was searched for cases of adamantinoma. Additionally a literature study was performed to identify cases of adamantinoma in childhood.

RESULTS

We identified six local cases of adamantinoma of the long bones, two boys (age 3 and 8 years) and four girls (mean age 8.8 years, range 3.0-14.0 years). The location of the tumour was the tibia in five and the tibia and fibula in one patient. In two patients initially a different diagnosis was made, which led to a delay in appropriate treatment. None of the children showed pulmonary metastases and all underwent total gross resection. On follow-up (mean 6.1 years, range 1.6-12.0 years) all children remained disease-free. Besides a discussion of our six patients, imaging features, histopathology, surgical approach and a literature review of childhood adamantinomas is presented.

CONCLUSION

Although the incidence of adamantinoma is low, it is important to recognize this rare bone tumour, since in the early stages of the disease adequate treatment will result in an excellent prognosis.

Adamantinoma of tibia: A study of 12 cases

BACKGROUND

Adamantinoma is a rare tumor of long bones that can be mistaken for a carcinoma, and numerous other lesions such as myoepithelial tumor, malignant mixed tumor of bone, fibrous dysplasia/osteofibrous dysplasia, and vascular tumors.

METHODS

The histology and clinical features of 12 cases accrued from the surgical pathology files over a period of 23 years were analyzed.

RESULTS

Of the 12 cases, 4 were men and 8 women, with a mean age of 30 years. Radiologically the tumor presented as a lytic, eccentric, intracortical lesion in the tibia. The histology revealed epithelial islands with basaloid, spindle, and squamous features on a background of fibrotic stroma. Three patients came back with local recurrences, and one of them developed pulmonary metastasis.

DISCUSSION

In this article, an attempt is made to study the morphology, biology, and the differential diagnoses of adamantinoma of long bones.

Extra copies of chromosomes 7, 8, 12, 19, and 21 are recurrent in adamantinoma

Adamantinoma of long bones is a rare neoplasm predominantly involving the tibia. Cytogenetic studies of adamantinoma are few. Cytogenetic or molecular cytogenetic analysis of four adamantinomas, and a review of eleven cases in the literature reveals extra copies of chromosomes 7, 8, 12, 19, and 21 as recurrent in this neoplasm. Adamantinoma may be confused with a variety of primary and metastatic epithelial and mesenchymal neoplasms. Observation of these aneuploidies may be useful in establishing the diagnosis of adamantinoma.

Current trends in the management of adamantinoma of long bones. An international study

BACKGROUND

Adamantinoma of long bones is a rare tumor. Published reviews of the orthopaedic management of adamantinoma have involved limited follow-up of small numbers of patients. The oncological aggressiveness of this tumor is unknown. Limb salvage is currently the treatment of choice for most adamantinomas. The purpose of this study was to evaluate the characteristics of adamantinoma of long bones as well as the oncological outcome and the complications of limb salvage operations.

METHODS

A retrospective study was designed to evaluate the clinical outcomes of limb salvage operations for the treatment of adamantinoma. Data on seventy biopsy-proven cases of adamantinoma treated between 1982 and 1992 at twenty-three different cancer centers in Europe and North America were obtained.

RESULTS

The median duration of follow-up was 7.0 years. The male:female ratio was 3:2, and the mean age was thirty-one years. Limb salvage was attempted in 91 percent (sixty-four) of the seventy patients, and the final rate of limb preservation was 84 percent (fifty-nine of seventy). Wide operative margins were obtained in 92 percent (fifty-eight) of sixty-three patients. An intercalary allograft was used to reconstruct the segmental bone defect in 51 percent (thirty-six) of the seventy patients. Reconstruction-related complications occurred in 48 percent (thirty) of sixty-two patients. Nonunion and fracture were the most common complications, occurring in 24 percent (fifteen) and 23 percent (fourteen) of sixty-two patients, respectively. Kaplan-Meier analysis demonstrated a rate of local recurrence of 18.6 percent at ten years. Wide operative margins were associated with a lower rate of local recurrence than marginal or intralesional margins were (p < 0.00005). Kaplan-Meier analysis showed a survival rate of 87.2 percent at ten years. There were no significant relationships between survival and the stage of the tumor (p = 0.058), duration of symptoms (p = 0.90), gender (p = 0.79), or wide operative margins (p = 0.14).

CONCLUSIONS

Current treatment of adamantinoma, including en bloc tumor resection with wide operative margins and limb salvage, provides lower rates of local recurrence than has been previously reported. In the present study, the limb preservation rate was 84 percent (fifty-nine of seventy), and the survival rate was 87.2 percent at ten years. The rate of complications related to the limb reconstruction was high.

Expression of growth factors and their receptors in adamantinoma of long bones and the implication for its histogenesis

Adamantinoma of long bones is a rare bone tumour with (immuno-) histological features of epithelial cells, surrounded by various amounts of osteofibrous tissue. Recent studies have indicated that cells with an epithelial phenotype are most probably the malignant element. There is still debate as to whether the fibrous part should be designed as a benign neoplastic element of a biphasic tumour or as a reactive non-neoplastic tissue next to an epithelioid bone tumour. The expression of fibroblast growth factor type 2 (FGF-2), epidermal growth factor (EGF), and their respective receptors FGFR-1 and EGFR, as well as the proliferation marker Ki-67, was studied in both constituents of adamantinoma in serial sections of 25 cases by immunohistochemistry. Expression of FGF-2 and its receptor was present in both constituents of adamantinoma, but predominated in the epithelial component. Expression of EGF and its receptor was restricted to the epithelial component of adamantinoma. Comparing osteofibrous dysplasia (OFD)-like adamantinoma with classic epithelial cell-rich adamantinoma, the expression of FGF-2, EGF, and EGFR was more intense and in a higher percentage of cells in classic adamantinoma. Proliferative activity was found nearly exclusively in the epithelial component. These data further substantiate the hypothesis that epithelial cells constitute the proliferating tumour cell population responsible for the malignant behaviour of adamantinoma. The data indicate that during progression, the epithelial cells acquire expression of FGF-2, EGF, and EGFR, accompanied by a higher proliferative activity. Within the epithelial cell population, there exists an autocrine pathway of growth stimulation. Furthermore, these data point to an interaction between the epithelial and fibrous components, in which the epithelial cells additionally stimulate fibrous cell growth via a paracrine pathway involving FGF-2.

Cytogenetic analysis of adamantinoma of long bones: further indications for a common histogenesis with osteofibrous dysplasia

Five adamantinomas of long bones were cytogenetically characterized to investigate the role of chromosomal aberrations in their histogenesis, as well as a putative relationship between adamantinoma and osteofibrous dysplasia (OFD). Three tumors had a classic histologic subtype, with abundant epithelium. Two of them revealed trisomies 7, 8, 12, and 19, combined with a balanced translocation, t(10;12), with centromere breakpoints in one tumor. The third showed a karyotype 51,XY, +X, +7, +12, +19, +21. The fourth tumor, of OFD-like subtype, showed trisomies 7, 8, and a small marker chromosome in a low percentage of cells. The fifth tumor, also of OFD-like subtype, displayed only a few keratin-positive cells from the multiple tissue blocks investigated. This latter tumor revealed a clonal abnormality with a karyotype 46,XX,t(2;11)(p23;q14)inv(11)(p14q14), which was confirmed with fluorescence in situ hybridization (FISH), using chromosome-specific library probes and chromosome 11 locus-specific probes. The trisomies 7, 8, and 12 also were described in OFD, which suggests a common histogenesis of OFD and adamantinoma. Our findings further support the probability of clonal origin of OFD. The OFD-like component may be an integral element of adamantinoma, rather than a tissue reaction to epithelial tumor cells.

Adamantinoma of the appendicular skeleton in children

The 260 cases of adamantinoma described in the world literature have been reviewed. Case histories of 60 patients up to the age of 16 years mirror those of adults. The mortality rate is 20% in children and adults. Wide excision with bone grafting is the ideal treatment for patients under 16 years.

Clonal chromosomal abnormalities in osteofibrous dysplasia. Implications for histopathogenesis and its relationship with adamantinoma

BACKGROUND

The pathogenesis of osteofibrous dysplasia, a rare fibroosseous lesion occurring almost exclusively in the tibia of children younger than 10 years of age, is not known. One theory is that osteofibrous dysplasia results from excessive resorption of bone with fibrous repair of the defect. Alternatively, osteofibrous dysplasia has been considered a congenital lesion or a variant of fibrous dysplasia. It has been hypothesized that osteofibrous dysplasia is a secondary reactive process to adamantinoma. Cytogenetic analysis is one form of investigation that has been instrumental in determining the origin of many disorders.

METHODS

Short-term cultures of two separate osteofibrous dysplasia specimens (approximately 1 year apart) from the tibia of an 11-year-old boy and 2 separate specimens (approximately 2 years apart) from the tibia of a 16-year-old boy were cytogenetically examined using standard procedures. Additionally, fluorescence in situ hybridization (FISH) studies were performed on uncultured cells of both specimens of the first patient using an alpha-satellite probe for chromosome 12.

RESULTS

Cytogenetic and FISH analysis revealed trisomy 12 in both specimens of the first patient. Trisomy for chromosomes 7, 8, and 22 was seen in both specimens of the second patient.

CONCLUSIONS

Osteofibrous dysplasia has not previously been subjected to cytogenetic analysis. Trisomy 7 and 12, however, have been reported in a clonally aberrant adamantinoma, potentially providing further support for a relationship between these two lesions. Most importantly, these findings demonstrate a clonal and possibly neoplastic origin for osteofibrous dysplasia of long bone.

Cytogenetic abnormalities in an ossifying fibroma from a patient with bilateral retinoblastoma

Cytogenetic analysis of a cemento-ossifying fibroma from a patient with nonfamilial bilateral multicentric retinoblastoma revealed three reciprocal translocations with the karyotype 46,XY,t(1;18)(q21;q21.3),t(3;10)(p13;q22),t(6;11)(p22;p15). Routine and high-resolution cytogenetic analysis of peripheral blood leukocytes showed an apparently normal, 46,XY chromosome pattern with no deletion of chromosome 13. Molecular analysis demonstrated no gross differences in the retinoblastoma gene or the TP53 gene between constitutional and tumor DNA. This is the first cytogenetic analysis of a cemento-ossifying fibroma and the first report of this tumor in a retinoblastoma patient. The data may be added to the small, but growing literature on cytogenetic aberrations in benign tumors and may lend insight into genes involved in cell proliferation and neoplastic transformation.