Comprehensive review of undifferentiated carcinoma of the pancreas: from epidemiology to treatment

Undifferentiated carcinoma (UC) of the pancreas is a rare subtype of pancreatic cancer displaying no definitive direction of differentiation. UC has been reported as a highly aggressive malignant neoplasm, with a median overall survival of <1 year, except for several surgical series. On the other hand, UC tissue sometimes contains non-neoplastic osteoclast-like giant cells (OGCs), and such cases have been reported to have relatively longer survival. Thus, the World Health Organization (WHO) classification histologically distinguishes UC with OGCs (UCOGCs) from UC, and UCs were subclassified into three subtypes: anaplastic UC, sarcomatoid UC and carcinosarcoma. However, still less is known about UC due to its rarity, and such situations lead to further difficulties in treatment for UC. To date, only surgical resection can offer curative treatment for patients with UC, and no clear evidence for chemotherapy exists for them. However, a retrospective cohort study and case reports showed that relatively promising results paclitaxel-containing regimens for treatment of patients with unresectable UC. Furthermore, high programmed cell death protein 1 expression has been reported in sarcomatoid UCs and UCOGCs, and promising responses to anti-programmed death-ligand 1 therapy have been described in case reports of UCOGCs. Recent advances in chemotherapeutic agents and molecular technologies are opening up the possibilities for expanded treatments.

Undifferentiated carcinoma with osteoclast‑like giant cells of the pancreas: A case report

Undifferentiated carcinoma with osteoclast-like giant cells of the pancreas (UCOGCP) is a rare pancreatic tumor that accounts for <1% of all primary pancreatic malignant tumors. Although the tumor is considered a variant of pancreatic ductal adenocarcinoma, there are substantial differences in the clinicopathological characteristics between UCOGCP and pancreatic ductal adenocarcinoma. Imaging examinations are useful in making a correct diagnosis, and providing a reasonable and effective surgical treatment regimen; however, the imaging characteristics of UCOGCP require further investigation. The present report describes a rare case of UCOGCP with rapid progression and poor prognosis. The patient could not undergo surgery and received chemotherapy drugs only. Chemotherapy did not markedly improve the outcome, and a follow-up 6 months after discharge showed that the patient had died. The present report describes this case and summarizes the available imaging findings to increase awareness, and to improve early diagnosis of this rare disease and therapeutic outcomes.

Significance of Histone H3.3 (G34W)-Mutant Protein in Pathological Diagnosis of Giant Cell Tumor of Bone

OBJECTIVE

This study aimed to examine the expression of Histone H3.3 glycine 34 to tryptophan (G34W) mutant protein in Giant Cell Tumor of Bone (GCTB).

METHODS

This analytic observation research used a cross-sectional study design on 71 bone tumors. The cases involved 54 tissue samples diagnosed as GCBT. It was divided into GCTB primer (n=37), recurrent GCTB (n=5), GCTB with metastasis (n=9), and malignant GCTB (n=3). There were 17 samples mimics of GCTB also tested, including chondroblastoma (n=1), giant cell reparative granuloma (n=2), giant cell of tendon sheath (n=7), chondromyxoid fibroma (n=2), aneurysmal bone cyst (n=2), and giant cell-rich osteosarcoma (n=3). The Immunohistochemistry was used to evaluate the expression of G34W-mutated protein in these bone tumors.

RESULT

The representation H3.3 (G34W) was expressed in the nuclei of mononuclear stromal cells but not stained on osteoclast-like giant cells. This study was analyzed by the Chi-square test, Fisher's test, specificity test, and sensitivity test. We obtained p = 0.001 for Histone H3.3 (G34W) mutant expression in GCTB vs Non-GCTB. Statistically, there was no significant difference in the expression level of Histone H3.3 (G34W) in the GCTB and its variants p-value = 0.183. We also obtained that the specificity of Histone H3.3 expression on GCTB was 100% and the sensitivity of Histone H3.3 on GCTB was 77.8%.

CONCLUSION

Histon H3.3 mutant as a mutated driver gene in an Indonesian GCTB can assist to diagnose GCTB and compare it from other bone tumors.

Osteoclast-like giant cells in hepatocellular carcinoma case description and review of the literature

BACKGROUND

The presence of osteoclast-like giant cells (OGC) in hepatocellular carcinoma (HCC) is rare and literature on this topic is scarce. In this article, we report on a case of a 77-year-old male patient with HCC with OGC and provide an overview of the current literature.

METHODS

We conducted a systematic search to find all available literature on OGC in HCC. The electronic databases PubMed, Web of Science, Embase and CENTRAL were searched from inception until October 2020.

RESULTS

Thirteen articles on this topic were identified and were included in this review. Data on 14 patients were available, described in twelve case reports, one patient in a patient series and the present case. Median age of included patients was 68 years. Two patients underwent neoadjuvant therapy prior to surgery. Of the 14 cases, eight tumours with OGC arose in a cirrhotic liver. Oncological outcome in this series was unfavourable, even after surgical resection, with a median disease-free survival of 75 d.

CONCLUSIONS

The presence of OGC in HCC is rare. Current literature is scarce, and suggests an unfavourable outcome in regard to overall survival of HCC.

[Undifferentiated pancreatic carcinoma with osteoclast-like giant cells]

In the structure of malignant oncological diseases of the Russian population, pancreatic cancer (PCa) occupies the 10th place with a high mortality rate in case of late diagnosis, which is primarily due to the minimal clinical manifestations of this pathology and the absence of precancer as a potential substrate for screening. Undifferentiated pancreatic carcinoma with osteoclast-like giant cell (UC-OGC) is a rare histological variant of PCa with discussed bidirectional histogenesis (epithelial and mesenchymal), epithelial-mesenchymal transition in the tumor and variable prognosis depending on the predominant cellular component. A review of the literature reflecting debatable issues of origin, clinical and pathological characteristics and prognosis of UC-OGC, as well as a description of a clinical case is relevant due to the rare occurrence of this tumor in the routine work of pathologists and oncologists.

Case report: Pathological and genetic features of pancreatic undifferentiated carcinoma with osteoclast-like giant cells

Objectives: Pancreatic undifferentiated carcinoma accounts for 2%-7% of pancreatic carcinomas. We aimed to investigate the pathological and genetic characteristics of pancreatic undifferentiated carcinoma with osteoclast-like giant cells and the key points of treatment. Methods: The clinical data and follow-up results of four patients diagnosed with pancreatic undifferentiated carcinoma with osteoclast-like giant cells between May 2015 and May 2020 at the First Affiliated Hospital of Xi'an Jiaotong University were retrospectively analyzed. Results: Chief complaints included "pain and discomfort in the upper abdomen" (2/4), "nausea and vomiting" (1/4) or no symptoms (1/4). Preoperative mildly elevated tumor markers included carcinoembryonic antigen (1/4) and CA19-9 (1/4). The tumors were located in the tail of the pancreas in three patients and the head and neck in one patient. Tumor metastasis was found in pancreatic adipose tissue in two patients and lymph node metastasis in one patient, with microscopic heterogeneous mononuclear cells and scattered osteoclast-like giant cells of various sizes. One patient (1/4) had a mucinous cystic tumor of the pancreas, and two patients (2/4) had adenocarcinoma of the pancreatic duct. Only one patient received postoperative gemcitabine combined with albumin-bound paclitaxel chemotherapy. Conclusion: Currently, treatment guidelines are lacking for PUC-OGC, and prognosis varies markedly. More cases must be reported to clarify its origination. The long-term follow-up of diagnosed patients and genetic mutation testing can also contribute to improving treatment and prognosis of this disease.

A case of osteoclastic variant of anaplastic thyroid carcinoma: Diagnostic and prognostic marker studies by cytology

Anaplastic thyroid carcinoma is an infrequent, but aggressive fatal subtype of thyroid cancer. The osteoclastic variant of anaplastic carcinoma is a rare subtype of anaplastic carcinoma with rare cases reported in the literature. Molecular targeted therapies have emerged for the anaplastic carcinoma, necessitating accurate pathologic diagnosis with additional ancillary testing for directing clinical management. We present here the cytological diagnosis of an anaplastic thyroid carcinoma-osteoclastic variant on fine-needle aspiration (FNA), with emphasis on the novelty of utilizing the least invasive procedure (aspiration cytology) for rendering pathological diagnosis as well as identifying potential prognostic markers for targeted immunotherapy.

Cutaneous atypical fibroxanthoma with osteoclast-like giant cell: a rare phenomenon

Atypical fibroxanthoma with osteoclast-like giant cells is a rare entity. We present the case of an elderly woman who presented with a pink-purple dome-shaped nodule with central hyperkeratotic crust. Biopsy revealed a cellular, dermal based tumor comprised of spindle, oval, and osteoclast-like giant cells with pleomorphism. The immunohistochemistry profile supported a diagnosis of atypical fibroxanthoma (AFX) with osteoclast-like giant cells. We performed a literature review through PubMed and Google Scholar for AFX with osteoclast-like giant cell formation and found 16 previously reported cases. We aim to provide a review and discuss features of these cases. We also discuss the pathogenesis of these osteoclast-like cells as well as potential pitfalls in diagnosis. This article is protected by copyright. All rights reserved.

Sequencing of an Undifferentiated Carcinoma with Osteoclast-Like Giant Cells of the Pancreas: A Case Report

Background: Undifferentiated carcinoma with osteoclast-like giant cells/osteoclast-like giant cell reaction (UC-OGC) is a rare form of pancreatic cancer historically associated with a poor prognosis. Molecular tumor profiling provides new information about tumor origins and a more nuanced understanding of the potential efficacy of different chemotherapeutic agents.

Presentation: A 69-year-old man presented with a 13-cm periampullary pancreatic mass. Biopsy of a neighboring lymph node was consistent with adenocarcinoma. After neoadjuvant chemoradiation, the patient underwent resection and the tumor was consistent with UC-OGC. Next-generation sequencing was performed with genomic and proteomic analyses analyzed by a molecular tumor board review. These analyses revealed genetic alterations similar to those seen in pancreatic ductal adenocarcinoma, as well as potential therapeutic targets for the patient's subsequent therapy.

Conclusions: Understanding a tumor's genetic changes allows for better understanding of its biology and may improve treatment efficacy. We believe that future study in tumor profiling will improve our understanding of rare cancers such as UC-OGC and also pave the way for the use of novel therapies to specifically target mutations in a broad range of more common tumors.

Giant cell tumor of soft tissue: FNA cytopathology of 4 cases, review of the literature, and comparison with giant cell tumor of bone

BACKGROUND

The cytopathology of a giant cell tumor of soft tissue (GCT-ST), a fibrohistiocytic neoplasm distinct from other giant cell-rich soft tissue tumors, is rarely reported. The authors report their experience with a series of 4 GCT-ST fine-needle aspiration (FNA) biopsy cases and compare them with a set from giant cell tumors of bone (GCTBs).

METHODS

The authors' cytopathology files were searched for GCT-ST examples with histopathologic confirmation. FNA biopsy smears were performed and examined with standard techniques.

RESULTS

Four cases of GCT-ST presenting as a primary soft tissue mass from 4 patients (3 males and 1 female; age range, 28-75 years, mean age, 53 years) were retrieved. FNA sites included the anterior tibia, buttock, shoulder, and upper back. Three cases were interpreted as suspicious for sarcoma radiographically. The specific diagnoses were atypical giant cell tumor of tendon sheath, suspicious for GCT-ST, atypical myxoid lesion with giant cells, and benign with osteoclast-like giant cells (OLGCs). No case was interpreted as malignant. Aspirates consisted of mononuclear polygonal cells, spindled fibroblast cell clusters, and large OLGCs to the near exclusion of other cell types. OLGCs possessed 10 or more nuclei per cell. A comparison with GCTB aspirates and single case reports from the literature showed comparable cytomorphology.

CONCLUSIONS

GCT-ST FNA smears mimic those of GCTBs containing a limited population of uniform spindle cell clusters, single dispersed polygonal cells, and cytologically banal OLGCs. GCT-ST should be considered in the differential diagnosis of aspirates containing numerous osteoclast-like giant cells.

Undifferentiated Pancreatic Carcinoma With Osteoclast-Like Giant Cells and Associated Ductal Adenocarcinoma With Focal Signet-Ring Features

Undifferentiated pancreatic carcinoma with osteoclast-like giant cells (UPC-OGC) is a unique and rare tumor characterized by the presence of highly atypical carcinoma cells and non-neoplastic osteoclast-like giant cells. The histogenesis of this tumor is unclear and data on its prognosis remain controversial. Some data show poor clinical outcomes in affected patients while other more recent studies report a better outcome especially for cases with pure UPC-OGC. There are currently no established reliable management guidelines for UPC-OGC partly because of its rarity and presence of conflicting data in the literature. Hence the need for continued reporting and further research on this neoplasm. We report an incidental finding of UPC-OGC with associated ductal adenocarcinoma and focal signet ring features in an elderly male patient who presented with symptoms of urinary tract infection (UTI).

Undifferentiated Pancreatic Carcinoma With Osteoclast-Like Giant Cells: What Do We Know So Far?

Undifferentiated carcinoma of the pancreas is an aggressive but rare tumor for which several other terms have been used to describe its histological appearance. In addition, as osteoclast-like giant cells may accompany undifferentiated carcinoma of the pancreas, the WHO Classification distinguishes undifferentiated carcinoma with osteoclast-like giant cells (UC-OGC) from plain undifferentiated carcinoma since there are a few histopathological and clinical differences. UC-OGC was initially thought to be associated with worse prognosis compared to invasive ductal pancreatic adenocarcinoma, since it is often unresectable at diagnosis and tends to recur rapidly even if completely resected. When true UC-OGGs are carefully dissected out from other anaplastic carcinomas, it becomes, however, clear that UC-OGCs do have more indolent behavior, especially the pure UC-OGCs. This mini-review summarizes the current knowledge on UC-OGC.

Invasive Ductal Breast Cancer with Osteoclast-Like Giant Cells: A Case Report Based on the Gene Expression Profile for Changes in Management

We report the case of a 49-year-old woman diagnosed with a rare histotype of early breast cancer (BC), invasive ductal carcinoma with osteoclast-like giant cells (OGCs), from the perspective of gene profile analysis tests. The patient underwent a quadrantectomy of the right breast with removal of 2 cm neoplastic nodule and three ipsilateral sentinel lymph nodes. The Oncotype Dx gave a recurrence score (RS) of 23, and taking into account the patient's age, an RS of 23 corresponds to a chemotherapy benefit of 6.5%. After a multidisciplinary collegial discussion, and in consideration of the patient's age, the absence of comorbidity, the premenopausal state, the rare histotype and the Oncotype Dx report, the patient was offered adjuvant chemotherapy treatment followed by hormone therapy. This case may be an example of the utility of integrating gene expression profiling tests into clinical practice in the adjuvant treatment decision of a rare histotype BC. The Oncotype Dx test required to supplement the histological examination made us opt for the proposal of a combined treatment of adjuvant chemotherapy followed by adjuvant hormone therapy. It demonstrates the importance of considering molecular tests and, in particular, the Oncotype Dx, in estimating the risk of disease recovery at 10 years in order to identify patients who benefit from hormone therapy alone versus those who benefit from the addition of chemotherapy, all with a view toward patient-centered oncology. Here, we discuss the possible validity and limitations of the Oncotype Dx in a rare luminal A-like histotype with high infiltrate of stromal/inflammatory cells.

Seven-year disease-free survival in a patient with osteoclast-like giant cell-containing pancreatic undifferentiated carcinoma: a case report and literature review

BACKGROUND

Undifferentiated carcinoma with osteoclast-like giant cells (UCOGC) of the pancreas is a very rare variant of pancreatic malignant neoplasm. It is regarded as a highly aggressive tumor with a worse prognosis than conventional pancreatic ductal adenocarcinoma.

CASE PRESENTATION

A 54-year-old male patient presented with 3-month recurrent epigastric distress. Computed tomography of the abdomen showed a large cystic mass in the distal pancreas. On macroscopic examination, the lesion had numerous multiloculated cystic cavities. Microscopically, the tumor predominantly comprised a considerable number of evenly distributed non-neoplastic osteoclast-like giant cells and a few neoplastic pleomorphic cells. Although extensive histologic sampling was conducted, a classic ductal adenocarcinoma component was not identified. The patient received no further treatment after his surgery and has been doing well with no evidence of recurrence or metastasis for >7 years.

CONCLUSIONS

Our results suggest that pure UCOGC has a significantly better prognosis and supports that pure UCOGC may represent a biologically distinct variant of pancreatic carcinoma and it should be separated from other undifferentiated pancreatic carcinomas.

Leiomyosarcoma with osteoclast-like (LMS-OGC) giant cells the breast: A report of a rare case

Leiomyosarcoma with osteoclast‐like giant cells (LMS‐OGC) has seldom been reported clinically. LMS‐OGC of the breast is extremely rare according to the literature. Here, we report a case of LMS‐OGC leiomyosarcoma with osteoclast‐like giant cells of the breast. A 51‐year‐old female patient presented with a breast mass which was treated surgically and the pathological examination of the tumor indicated LMS‐OGC. Microscopically, the tumor was composed of spindle cells arranged in bundles or spokes with giant tumor cells and mitosis. Eosinophilic cytoplasm and morphologically benign osteoclast‐like cells were mixed together. Immunohistochemistry examination revealed SMA and desmin were positive with a Ki‐67 proliferation index of 40%. However, CK (AE1/AE3), E‐cadherin, ER, PR, CD34, S‐100 and CD10 were negatively expressed in the tumor tissue. LMS‐OGC is a soft tissue malignant tumor which develops extremely rarely in the breast. It should be differentiated and diagnosed according to the history, histological characteristics and immunohistochemical staining.

Two Cases of Rare Pancreatic Malignancies

Background: Pancreatic adenocarcinoma remains one of the most lethal malignancies with little treatment advancements. Other less common pancreatic cancer histologies have different outcomes and disease course. In this article, we report two cases of rare pancreatic tumors.

Presentation: The first case is a 59-year old, who was undergoing surveillance of a known pancreatic cyst, which eventually enlarged. The mass was resected and pathology revealed undifferentiated carcinoma with osteoclast-like giant cells. The patient did not receive any adjuvant therapy and has had no recurrence. The second case is of a 60-year-old patient who presented with signs and symptoms of pancreatic insufficiency and was found to have clear cell adenocarcinoma of the pancreas. She received neoadjuvant chemoradiotherapy followed by surgical resection without complications.

Conclusion: Our article presents these rare malignancies, which had outcomes that are more encouraging than typical adenocarcinomas. Genomic sequencing can provide more insight into these tumors and potentially provide targets for therapy.

Denosumab as a potential therapeutic option for leiomyosarcoma with osteoclast-like giant cells: A case report

Bone leiomyosarcoma is a rare primary osseous malignant tumor with a high metastatic potential. Similar to other bone sarcomas, high histological grade and tumor stage are predictive of a poor outcome. We herein present our experience with treating a 64-year-old woman with bone leiomyosarcoma accompanied by multiple bone metastases. A biopsy revealed occasional osteoclast-like giant cells. In addition to radiation therapy, the osteoclastogenesis inhibitor denosumab was administered but the patient did not undergo adjuvant chemotherapy or surgery. Good clinical and short-term radiological responses to denosumab have been observed for 2 years. Therefore, denosumab may represent a viable treatment option without the need for adjuvant chemotherapy.

Squamous cell carcinoma of lung associated with osteoclast-like giant cells: report of a case

Resently, we treated a 69-year-old patient with squamous cell carcinoma of lung with osteoclast-like giant cells which were similar with the giant cell tumor of bone. The clinical and pathological characteristics of this case were presented, and the literatures were reviewed. The tumor differed histologically from the pleomorphic carcinoma, which occurs most commonly in the lung and showed diverse pleomorphic manifestation with benign looking osteoclast-like multinucleated cells and bizarre giant cells. In addition, undifferentiated carcinoma with a sarcoma-like appearance containing small areas of papillary adenocarcinoma was evident in the tumor. Histological features and immunohistochemical staining could be helpful in differential diagnosis.

Giant cell rich osteosarcoma of the mandible with abundant spindle cells and osteoclast-like giant cells mimicking malignancy in giant cell tumor

Giant cell rich osteosarcoma is a relatively unusual histological form of osteosarcoma, common lesion usually presenting in the long bones of the appendicular skeleton. The occurrence in the mandible is exceptional rare. Histologically, this tumor tends to be a highly anaplastic, pleomorphic tumor in which the tumor cells may be: plasmacytoid, fusiform, ovoid, small round cells, clear cells, mono-or multinucleated giant cells, or, spindle cells. Herein, we present a case with the sternum and first thoracic vertebra metastasis from primary giant cell rich osteosarcoma of the mandible in a 28 year-old Chinese female. The tumor was predominantly composed of abundant spindle cells with marked atypia and numerous osteoclast-like giant cells reminiscent of malignancy in giant cell tumor. The unusual histological appearance can pose a great diagnostic challenge. It may be easily misdiagnosed, especially if the specimen is limited or from fine-needle aspiration.

Squamous cell carcinoma of the uterine cervix associated with osteoclast-like giant cells: A case report and review of the literature

Squamous cell carcinoma is a common malignant tumor of the uterine cervix. The present study reports the case of squamous cell carcinoma of the uterine cervix with osteoclast-like giant cells (OGCs) in an 84-year-old female who had suffered from irregular vaginal bleeding for one month. Colposcopy was performed and a cauliflower-like mass was identified in the front lip of the uterine cervix. Biopsy was then performed, and the tumor was found to be composed of epithelial cell nests, ranging in size. The neoplastic cells exhibited unclear boundaries and eosinophilic cytoplasm. Additionally, the nuclei were atypical and mitosis was observed. Among the epithelial nests, there were numerous OGCs with abundant eosinophilic cytoplasm, as well as multinucleation with bland nuclei. By immunohistochemical staining, the epithelial cells were positive for cytokeratin, while negative for CD68 and vimentin. By contrast, the immunophenotype of the OGCs was the exact opposite. Based on the histological characters, a diagnosis of squamous cell carcinoma of the uterine cervix associated with OGCs was made. Considering the age of the patient, radiotherapy was administered. The patient succumbed to brain metastasis of the tumor after eight months of follow-up.

Long-term survivor of a resected undifferentiated pancreatic carcinoma with osteoclast-like giant cells who underwent a second curative resection: A case report and review of the literature

An undifferentiated carcinoma with osteoclast-like giant cell tumors (UC-OGC) is a rare type of tumor, which predominantly occurs in the pancreas. Due to the rarity of UC-OGC, sufficient clinical data are not available and its prognosis following surgical resection remains unclear. In the current report the case of a 37-year-old female is presented, in whom an UC-OGC of the pancreas was removed and following this, a second carcinoma of the remnant pancreas was removed during a second surgical procedure. At the patient’s initial admission, the preoperative images demonstrated a well-demarcated mass with a marked cystic component at the pancreatic head. The patient underwent a pylorus-preserving pancreaticoduodenectomy. The final pathological diagnosis was UC-OGC of the pancreas and the tumor was considered to have been curatively resected based on the histopathological findings. Four years after the initial surgery, a small mass was detected in the remnant pancreas and a partial resection of the remnant pancreas was subsequently performed. Histopathologically, the tumor consisted of a poorly differentiated tubular adenocarcinoma. A retrospective pathological analysis showed a segment of a poorly differentiated tubular adenocarcinoma in the initial resected specimen. Therefore, the final diagnosis was considered to be an intra-pancreatic recurrence of UC-OGC. The patient survived 66 months following the initial surgery and 18 months since the second resection. A meta-analysis was performed in the current study by comparing UC-OGC patients who survived more than two years following surgical resection (long-term survivors) with those who succumbed less than one year following surgical resection (short-term survivors). The characteristics of the short-term survivors were patients of an older age, males, and those exhibiting smaller tumors, positive lymph node metastasis, and concomitant components of ductal adenocarcinoma, as well as pleomorphic giant cell carcinoma. The concomitant component of mucinous cystic neoplasm was not considered to be a prognostic factor. To the best of our knowledge, the patient in the current report is the first five-year survivor following a curative second resection.

Numerous osteoclast-like giant cells in metastases from lung adenocarcinoma, but absent from primary tumor

We report a rare case of lung adenocarcinoma in a 54-year-old man, in whom osteoclast-like giant cells (OCGCs) were found only in metastases. Autopsy revealed that metastases involving the tongue, gallbladder, stomach, intestines, right adrenal gland, and bones contained numerous OCGCs. Some metastases to the lungs and liver also contained OCGCs, but the primary tumor and metastases to the right atrium, spleen, left adrenal gland, and lymph nodes did not. Primary lung carcinoma cells were positive for cytokeratin 7 (CK7), epithelial membrane antigen (EMA), thyroid transcription factor 1 (TTF-1), and Napsin A, but were negative for vimentin and CD68. Frequently poorly cohesive metastatic carcinoma cells admixtured with OCGCs showed weak CK7/EMA positivity, no TTF-1/Napsin A staining, and newly expressed vimentin. OCGCs were positive only for CD68 and vimentin, implying reactive cells. OCGCs can develop only in metastatic lesions, possibly associated with their anaplastic changes or epithelial mesenchymal transition.

Receptor activator of NF-kappaB ligand (RANKL) is expressed in chondroblastoma: possible involvement in osteoclastic giant cell recruitment

AIMS

Chondroblastoma is a rare, locally aggressive bone tumour that causes osteolytic destruction at the epiphyseal end of the affected bone. It is possible that tumour cells may stimulate osteoclastogenesis and osteolytic destruction through the production of receptor activator of NF-kappaB ligand (RANKL), which is a key molecule essential for regulating osteoclast formation and activity. Therefore, the expression of RANKL at both the mRNA and the protein level was investigated in chondroblastoma tumour tissue obtained from patients.

METHODS

The expression of RANKL gene transcripts was analysed by the reverse transcription-polymerase chain reaction (RT-PCR), and the cellular localisation of RANKL mRNA and protein was demonstrated by means of in situ hybridisation and immunohistochemistry.

RESULTS

RT-PCR analysis indicated that RANKL mRNA was present in all chondroblastoma specimens and normal cancellous bone samples, but not in normal articular cartilage and chondrosarcoma tissues. In contrast, gene transcripts of osteoprotegerin (OPG), the decoy receptor of RANKL, were detected in all types of tissues. The chondroid origin of neoplastic mononuclear cells in chondroblastoma was confirmed by positive S-100 immunohistochemical staining. Both RANKL mRNA and protein were exclusively expressed in these neoplastic mononuclear cells.

CONCLUSIONS

These findings suggest that RANKL may be involved in the tumour cell induced recruitment of osteoclast-like cells and consequent osteolytic bone destruction in chondroblastoma.