Chondroblastomas but not chondromyxoid fibromas express cytokeratins: an unusual presentation of a chondroblastoma in the metaphyseal cortex of the tibia

Periosteal chondroblastoma of the femoral neck: two cases and a review of the literature

Chondroblastoma is a rare benign cartilaginous tumor mostly confined to the epiphyses and apophyses. Cases outside the epiphyseal region are exceedingly rare. Extramedullary chondroblastomas are exceptional; to our knowledge, only two cases qualified as "periosteal chondroblastoma" have been described in the literature. We report two cases of metaphyseal periosteal chondroblastoma both located on the inferior surface of the femoral neck. Both cases were paucicellular with an unusual dense sclerotic reaction. The diagnosis of chondroblastoma was supported by the expression of histone 3.3, K36M mutant in tumor cells.

Distal Femoral Non-Epiphyseal Cortical Chondroblastoma Confirmed with H3F3B p. Lys36Met Mutation

Background: Chondroblastoma is a primary bone tumor typically arising from the intramedullary space of the epiphysis or epimetaphysis. A non-epiphyseal chondroblastoma is uncommon. Case report: An 11-year-old girl presented with an eccentric cortical osteolytic lesion in the distal femur metaphysis. The typical morphology, diffuse H3.3 K36M immunohistochemical expression and H3F3B point mutation (c. 110A > T) unequivocally supported the diagnosis of chondroblastoma. Discussion: We described a non-epiphyseal cortical-based chondroblastoma involving the distal femur harboring the typical H3F3B mutation. Non-epiphyseal chondroblastoma may harbor the H3F3B mutation.

Chondroblastomas presenting in adulthood: a study of 39 patients with emphasis on histological features and skeletal distribution

AIMS

Chondroblastomas (CB) are rare bone tumours that typically arise in the epiphysis/apophysis of long bones in skeletally immature patients. We explore the clinicopathological features of CB presenting in adults.

METHODS AND RESULTS

CB in patients ≥20 years of age were retrieved from our institutional archives. Thirty-nine CB were identified (29 male/10 female; aged 20-54 years). Twenty (51%) cases occurred in long tubular bones, 10 (26%) in small bones of the feet, five (13%) in flat bones and four (10%) in the patella. All cases showed classic cytological features of CB, and chondroid matrix was universally present. Calcification was identified in 10 cases (26%), including various combinations of serpiginous (n = 7), punctate (n = 6), classic chicken-wire (n = 4) and psammomatous (n = 2) patterns. Haemosiderin (n = 19), woven bone (n = 13), secondary aneurysmal bone cyst formation (n = 8), foamy macrophages (n = 4), hyalinised vascular spaces (n = 2) and cholesterol clefts (n = 2) were noted. Follow-up information (n = 32, 1-452 months) revealed local recurrence in three patients, all >40 years of age with flat bone origin, one of which developed pulmonary metastases 132 months after initial diagnosis.

CONCLUSIONS

CB in patients >20 years of age more frequently involves the short bones of the hands/feet and flat bones compared to those arising in their younger counterparts. A subset may harbour extensive serpiginous or psammomatous calcification rather than the classic chicken-wire pattern. Although the overall local recurrence rate in adulthood is approximately 10%, all three patients with recurrent disease had tumours involving flat bones, suggesting that tumours arising in these sites may behave more aggressively.

Selected Giant Cell Rich Lesions of the Temporal Bone

Giant cell rich lesions of the temporal bone encompass a wide spectrum of disease that includes infectious, reactive, and neoplastic processes. When dealing with any lesion that can potentially involve bone, it is important to understand both the clinical presentation and to correlate the histologic findings with the radiologic imaging. This review discusses the clinical, the pathologic features including the differential diagnosis, and the treatment of some of the more commonly encountered giant cell rich entities in this region.

Chondroblastoma of the rib in a 47-year-old man: a case report with a systematic review of literature

Chondroblastoma is an uncommon benign bone tumour arising typically in the epiphysis. Few cases of chondroblastoma of the rib have been reported in the literature. We describe a case of chondroblastoma of a 47-year-old man located in the body of the IX right rib. The patient presented a moderate right thoracic pain with an apparently palpable mass. Computed tomography (CT) scan showed a well-defined oval 49 mm × 43 mm lesion with the lytic bone destruction of the rib. A surgical resection was performed with an excellent outcome and no recurrence after 4-year follow-up. We also conducted a systematic review of literature where we evidenced that chondroblastoma could affect people of all age, but it's most common in children and young adult. Surgical resection constitutes the treatment of choice.

Surface-based chondroblastoma of the tibia: a unique presentation

BACKGROUND

Chondroblastoma is a benign tumor classically located within the epiphysis of the long bones. The tumor is believed to arise from immature cells of the epiphyseal plate. Purely metaphyseal or diaphyseal chondroblastoma is exceedingly uncommon, occurring in approximately 2% of chondroblastoma cases. In all of these non-epiphyseal-based cases, the tumor has been intramedullary.

METHODS

We describe the histologic and imaging features of the first detailed description of a surface-based chondroblastoma.

RESULTS

The tumor was located in the anteromedial midshaft of the tibia in a 47-year-old male.

CONCLUSION

We discuss the diagnostic considerations and possible etiology of chondroblastoma given this unusual location.

A fatal case of pure metaphyseal chondroblastoma

The chondroblastoma (CB) is a rare cartilaginous tumour; it represents less than 1% of all bone tumours. It is mostly localised at the level of the epiphysis of long bones. We report a fatal case of pure metaphyseal CB of the tibia in a 9-year-old boy whose pulmonary metastases developed soon after operative therapy of the primary tumour.

Primary juxtacortical myoepithelioma/mixed tumor of the bone: a report of 3 cases with clinicopathologic, immunohistochemical, ultrastructural, and molecular characterization

We describe the clinicopathological, immunohistochemical, and molecular features of 3 primary juxtacortical myoepithelioma/mixed tumor of bone. The patients were 2 males (13 and 23 years of age) and a 15-year-old female. The juxtacortical lesions were all located in the femur, and were surgically removed, 2 with wide margins and one with marginal margins. This latter tumor recurred locally 18 months later. The 3 patients were free of disease at 6 to 17 months follow-up. Histologically, all lesions showed a prominent multinodular architecture, and were formed by epithelioid and stellate elements, organized in solid sheets, or embedded in myxoid or chondroid matrix. Areas of osteoid formation were also observed. One tumor had the appearance of classical mixed tumor, showing aspects of duct formation and focal squamous differentiation. Immunohistochemically, all cases were positive for cytokeratins, epithelial membrane antigen, and S100 protein. The expression of other myoepithelial markers, including p63, glial fibrillary acid protein and calponin was more limited. No rearrangement of Ewing sarcoma region 1 (EWSR1) and fused in sarcoma (FUS) genes was observed by fluorescent in situ hybridization. To our knowledge, this is the first report of primary myoepitheliomas of bone arising at juxtacortical sites. These lesions must be distinguished from other benign and malignant bone and cartilage-forming surface tumors, including periosteal chondroma and chondrosarcoma, juxtacortical chondromyxoid fibroma, and periosteal and paraosteal osteosarcoma. The clinicoradiologic presentation and their histological and immunohistochemical features are distinctive enough to allow the separation from these entities.

Chondroblastoma in the long bone diaphysis: a report of two cases with literature review

To investigate the clinical characteristics of chondroblastoma with an emphasis on lesions located in the long bone diaphysis, we reviewed the clinical data of 7 patients with histologically proven chondroblastoma treated in Tianjin Medical University Cancer Hospital and Fudan University Cancer Hospital between January 1995 and May 2009. There were two rare cases of chondroblastoma in the long bone diaphysis. One patient with a lesion in the tibial diaphysis underwent intralesional curettage and bone grafting, and the postoperative bone function was measured as excellent according to the Enneking scoring system. The patient was still alive upon follow-up at 60 months. The other patient with a lesion in the humeral diaphysis underwent resection, and the postoperative bone function was excellent at 48 months, at which there was no evidence of recurrence or metastasis. Thus, except for the distinctive site of the long bone diaphysis, which made diagnosis difficult, the patients' ages, symptoms, X-ray and CT images, treatment, and prognosis were in accordance with typical lesions in the epiphysis and metaphysis. The diagnosis of chondroblastoma in the long bone diaphysis significantly depends on histopathologic characteristics.

Discovered on gastrointestinal stromal tumour 1 (DOG1): a useful immunohistochemical marker for diagnosing chondroblastoma

AIMS

  Cellular areas of chondroblastoma are composed of polygonal chondroblasts with indented nuclei and scattered osteoclast-type multinucleated cells. To learn more about the phenotype of chondroblasts, we investigated the expression of several established immunohistochemical markers in chondroblastomas.

METHODS AND RESULTS

  Nine chondroblastomas were analysed using immunohistochemical antibodies [CD34, α-smooth muscle actin (α-SMA), DOG1, CD117, AE1/AE3 and CD163]. Ten chondromyxoid fibromas, seven giant cell tumours of bone and four foetal proximal femurs were also analysed. The cellular areas of each chondroblastoma contained nests of DOG1(+) αSMA(+) CD117(-) CD34(-) chondroblasts, a phenotype that was not detected in chondromyxoid fibroma cases or in giant cell tumours. Although AE1/AE3 was expressed in all chondroblastomas, the staining intensity and proportion of the positive cells varied widely. Intra-lesional CD163(+) macrophages were detected in all cases of chondroblastoma, chondromyxoid fibroma and giant cell tumours.

CONCLUSIONS

  Our results demonstrated nests of membranous DOG1(+) chondroblasts located within cellular portions of chondroblastoma containing diffuse heterogeneous infiltrates of mostly DOG1(-) chondroblasts, CD163(+) macrophages and multinucleated osteoclastic giant cells. Thus, chondroblastoma can be added to the tumours that are usually positive for DOG1, alongside gastrointestinal stromal tumour (GIST), rare solid-pseudopapillary neoplasms of the pancreas and exceptional mesenchymal tumours including uterine type retroperitoneal leiomyoma, peritoneal leiomyomatosis and synovial sarcoma.

Metaphyseal and diaphyseal chondroblastomas

OBJECTIVE

Epiphyseal/apophyseal locations are important diagnostic radiological features of chondroblastomas (CB). Although the tumor may secondarily involve the metaphysis, reports of primary metaphyseal or diaphyseal CB without any epiphyseal or apophyseal involvement are exceptionally rare and frequently present as a diagnostic dilemma. The purpose of this study was to present seven cases of pure metaphyseal and/or diaphyseal CB along with a review of pertinent literature.

METHODS

A retrospective review of databases at two major referral centers revealed 390 cases of CB between 1960 and 2009. Out of these, seven histologically proven CB cases (1.8%) were found to be radiologically located in metaphysis and/or diaphysis, without involving the epiphysis and/or apophysis, and formed the study cohort.

RESULTS

There were four males and three females (age range 2-25 years). Locations included proximal femur (n = 1), distal femur (2), proximal humerus (2), clavicle (1), and proximal radius (1). All lesions showed marginal sclerosis. A periosteal reaction was seen in five cases (71%), cortical expansion in four cases (57%), and chondroid matrix in four cases (57%). A CT (two cases) demonstrated a matrix in both cases. An MR (one case) showed extensive perilesional edema. Bone scan (one case) showed intense uptake.

CONCLUSION

Pure metaphyseal and/or diaphyseal CB are exceedingly rare. A presumptive diagnosis may be considered in the appropriate age group in the presence of chondroid matrix, perilesional edema, periosteal reaction, and marginal sclerosis. Regardless of all the diagnostic possibilities, biopsy may still be required. However, knowledge of this entity will help make the final diagnosis and guide the correct treatment.

Benign cartilaginous tumors of bone: from morphology to somatic and germ-line genetics

Benign cartilaginous tumors of bones, intrinsic to their name, are tumors forming cartilaginous matrix with a clinically benign behavior. In this group, we recognize osteochondromas, (en)chondromas, chondroblastomas, and chondromyxoid fibromas. This group includes common tumors, that is, osteochondroma and (en)chondroma as well as rare tumors such as chondroblastoma and chondromyxoid fibroma. Several benign and malignant tumors may mimic benign cartilaginous tumors of bones. We reviewed the main morphologic features and the differential diagnosis is discussed. The genetics of these tumors is intriguing ranging from single gene event (ie, EXT mutation in multiple osteochondromas) to heterogeneous rearrangements with no recurrent involved chromosomal regions such as in chondroblastoma. The main genetic findings are hereby reviewed.