The prognostic significance of histomorphometry and immunohistochemistry in giant cell tumors of bone

Giant Cells of Various Lesions Are Characterised by Different Expression Patterns of HLA-Molecules and Molecules Involved in the Cell Cycle, Bone Metabolism, and Lineage Affiliation: An Immunohistochemical Study with a Review of the Literature

Giant cells (GCs) are thought to originate from the fusion of monocytic lineage cells and arise amid multiple backgrounds. To compare GCs of different origins, we immunohistochemically characterised the GCs of reactive and neoplastic lesions (n = 47). We studied the expression of 15 molecules including HLA class II molecules those relevant to the cell cycle, bone metabolism and lineage affiliation. HLA-DR was detectable in the GCs of sarcoidosis, sarcoid-like lesions, tuberculosis, and foreign body granuloma. Cyclin D1 was expressed by the GCs of neoplastic lesions as well as the GCs of bony callus, fibroid epulis, and brown tumours. While cyclin E was detected in the GCs of all lesions, p16 and p21 showed a heterogeneous expression pattern. RANK was expressed by the GCs of all lesions except sarcoid-like lesions and xanthogranuloma. All GCs were RANK-L-negative, and the GCs of all lesions were osteoprotegerin-positive. Osteonectin was limited to the GCs of chondroblastoma. Osteopontin and TRAP were detected in the GCs of all lesions except xanthogranuloma. RUNX2 was heterogeneously expressed in the reactive and neoplastic cohort. The GCs of all lesions except foreign body granuloma expressed CD68, and all GCs were CD163- and langerin-negative. This profiling points to a functional diversity of GCs despite their similar morphology.

Nuclear β-catenin translocation plays a key role in osteoblast differentiation of giant cell tumor of bone

Denosumab is a game-changing drug for giant cell tumor of bone (GCTB); however, its clinical biomarker regarding tumor ossification of GCTB has not been elucidated. In this study, we investigated the relationship between Wnt/β-catenin signaling and the ossification of GCTB and evaluated whether endogenous nuclear β-catenin expression predicted denosumab-induced bone formation in GCTB. Genuine patient-derived primary GCTB tumor stromal cells exhibited osteoblastic characteristics. Identified osteoblastic markers and nuclear β-catenin translocation were significantly upregulated via differentiation induction and were inhibited by treating with Wnt signaling inhibitor, GGTI-286, or selective Rac1-LEF inhibitor, NSC23766. Furthermore, we reviewed the endogenous ossification and nuclear β-catenin translocation of 86 GCTB clinical samples and elucidated that intra-tumoral ossification was significantly associated with the nuclear translocation. Three-dimensional quantitative analyses (n = 13) of tumoral CT images have revealed that the nuclear β-catenin translocation of naïve GCTB samples was significantly involved with the denosumab-induced tumor ossification. Our findings suggest a close relationship between the nuclear β-catenin translocation and the osteoblastic differentiation of GCTB. Investigations of the nuclear β-catenin in naïve GCTB samples may provide a promising biomarker for predicting the ossification of GCTB following denosumab treatment.

Histopathological, immunohistochemical, and image analytic parameters characterizing the stromal component in primary and recurrent giant cell tumor of bone

Giant cell tumor (GCT) of bone is a benign locally aggressive tumor whose biological behavior is unpredictable. Currently, there are no definitive clinical, histological, biochemical, or immunological parameters that can predict its behavior. This study was undertaken to examine whether delineation of reactive and neoplastic stromal component of GCT can help in this regard. 55 cases of GCT (30 primary, 25 recurrent) were subjected to histopathological grading, immunohistochemistry, and image analysis. Spindling of stroma was more frequent in recurrent GCT with 64% cases having more than 50% spindled stroma (p < 0.001). Number of mitosis/10 HPF and higher grade were more in recurrent GCT. Mean percentage positivity for CD68 (38.36%) and α1-ACT (70.86%) was higher in primary than recurrent GCT. PCNA and MiB-1 labeling indices were higher in recurrent (42.62% and 9.18%, respectively) than in primary group (24.75% and 7.7%, respectively). A single numerical parameter encompassing stromal cell population and its proliferation was derived as ratio of PCNA/CD68 and PCNA/α1-ACT. Both ratios were higher in recurrent (0.81 ± 0.38; 1.58 ± 1.50) than in primary GCT (0.58 ± 0.62; 0.34 ± 0.29) (p = 0.002; 0.01). On image analysis, parameters significantly different between the two groups were nuclear area and nuclear integrated optical density. It was thus concluded that recurrent GCT shows higher grade, increased mitosis, more spindling, fewer reactive components, and higher proliferation than primary GCT. Delineation of reactive component (α1-ACT positive) and proliferating component (PCNA positive cells) using immunohistochemistry with calculation of the PCNA/ACT ratio delivers more information than image analysis.

Expression of IMP3 and IGF2 in giant cell tumor of spine is associated with tumor recurrence and angiogenesis

PURPOSE

Giant cell tumor (GCT) of bone is a vessel-rich and infiltrative tumor, but the fundamental knowledge of its biological behavior remains unknown now.

METHODS

In this study, we evaluated the expression levels of Insulin-like growth factor 2 mRNA-binding protein 3 (IMP3), Insulin-like growth factor 2 (IGF2) and CD105 in 38 patients with GCT of spine by Immunohistochemical staining. Additionally, we also analyzed their correlations with clinicopathological factors of giant cell tumor of spine.

RESULTS

The results showed that positive expression of IMP3 and IGF2 was tightly related to the tumor extension and local recurrence of GCT (P < 0.05), but it did not indicate any association with patients' age, gender, tumor location and size. The mean microvessel densities (MVDs) of IMP3 and IGF2 were significantly higher in positive group than negative group (P < 0.05). Moreover, a significant correlation was found between IMP3 and IGF2 expression (r = 0.355, P = 0.029). The log-rank test revealed that local recurrence-free survival time was significantly shorter in the IMP3 positive group (P = 0.004), and the difference in the IGF2 positive group and negative group was also statistically significant (P = 0.008).

CONCLUSION

IMP3 and IGF2 might be potential biomarkers for GCT of spine in regulating the angiogenesis of giant cell tumor of bone and predicting the patients' prognosis.

A review of the chemistry and uses of crocins and crocetin, the carotenoid natural dyes in saffron, with particular emphasis on applications as colorants including their use as biological stains

The perennial flowering plant, saffron crocus (Crocus sativus L.), is the source of the most expensive spice in the world. The dried stigmas of saffron flowers are the source of a natural dye, saffron, which has been used from ancient times for dyeing silk and fabric rugs, and for painting; it also has been used for cooking and in medicine. The yellow compounds present in the dye include crocins, which are 20-carbon water soluble glycosyl derivatives of the carotenoid, crocetin, and the dicarboxylic acid itself. We review the chemistry of these compounds and discuss various applications of saffron as a natural dye. We review in particular the use of saffron or its constituents in histopathologic techniques.

Myofibroblastic differentiation of stromal cells in giant cell tumor of bone: an immunohistochemical and ultrastructural study

The nature of the mononuclear stromal cells (MSCs) in giant cell tumor of bone (GCTB) has not been thoroughly investigated. The purpose of this study was to evaluate the degree and significance of myofibroblastic differentiation in 18 cases of GCTB by immunohistochemistry (IH) and/or electron microscopy (EM). All immunostained cases were found positive for smooth muscle actin (SMA) and/or muscle specific actin (MSA), most in 1-33% of the MSCs. Ultrastructurally, most MSCs were fibroblasts, and a significant number of cells displayed myofibroblastic differentiation. Myofibroblasts are an important component of MSCs in GCTB. The myofibroblastic population may be responsible in part for the production of matrix metalloproteinases (MMPs), which probably play a role in bone destruction, tumor aggression, and recurrence.

Denosumab induces tumor reduction and bone formation in patients with giant-cell tumor of bone

PURPOSE

Giant-cell tumor of bone (GCTB) is a locally aggressive, benign osteolytic tumor in which bone destruction is mediated by RANK ligand (RANKL). The RANKL inhibitor denosumab is being investigated for treatment of GCTB. We describe histologic analyses of GCTB tumor samples from a phase II study of denosumab in GCTB.

EXPERIMENTAL DESIGN

Adult patients with recurrent or unresectable GCTB received subcutaneous denosumab 120 mg every 4 weeks (with additional doses on days 8 and 15). The primary histologic efficacy endpoint was the proportion of patients who had a 90% or more elimination of giant cells from their tumor. Baseline and on-study specimens were also evaluated for overall tumor morphology and expression of RANK and RANKL.

RESULTS

Baseline tumor samples were typically composed of densely cellular proliferative RANKL-positive tumor stromal cells, RANK-positive rounded mononuclear cells, abundant RANK-positive tumor giant cells, and areas of scant de novo osteoid matrix and woven bone. In on-study samples from 20 of 20 patients (100%), a decrease of 90% or more in tumor giant cells and a reduction in tumor stromal cells were observed. In these analyses, thirteen patients (65%) had an increased proportion of dense fibro-osseous tissue and/or new woven bone, replacing areas of proliferative RANKL-positive stromal cells.

CONCLUSIONS

Denosumab treatment of patients with GCTB significantly reduced or eliminated RANK-positive tumor giant cells. Denosumab also reduced the relative content of proliferative, densely cellular tumor stromal cells, replacing them with nonproliferative, differentiated, densely woven new bone. Denosumab continues to be studied as a potential treatment for GCTB.

Epidermal growth factor receptor signalling contributes to osteoblastic stromal cell proliferation, osteoclastogenesis and disease progression in giant cell tumour of bone

AIMS

Epidermal growth factor receptor (EGFR) is implicated in bone remodelling. The aim was to determine whether EGFR protein expression contributes to the aggressiveness and recurrence potential of giant cell tumour of bone (GCTB), an osteolytic primary bone tumour that can exhibit markedly variable clinical behaviour.

METHODS AND RESULTS

Immunohistochemical analysis on tissue microarrays (TMA) of 231 primary, 97 recurrent, 17 metastatic and 26 malignant GCTBs was performed using TMA analysis software and whole digital slides allowing validated scoring. EGFR expression was restricted to neoplastic stromal cells and was significantly more frequent in recurrent (71 of 92; 77%) than in non-recurrent GCTBs (86 of 162; 53%) (P = 0.002); and in clinicoradiologically aggressive (31 of 43; 72%) than latent (27 of 54; 50%) cases (P = 0.034). Detecting phosphotyrosine epitopes pY1068 and -pY1173 indicated active EGFR signalling, and finding EGFR ligands EGF and transforming growth factor-α restricted to cells of the monocytic lineage suggested paracrine EGFR activation in stromal cells. In functional studies EGF supported proliferation of GCTB stromal cells, and the addition of EGF and macrophage-colony stimulating factor promoted osteoclastogenesis.

CONCLUSION

In GCTB, EGFR signalling in neoplastic stromal cells may contribute to disease progression through promoting stromal cell proliferation and osteoclastogenesis.

Giant Cell Tumor of Bonelike Lesion in a Trp53 Mutant Mouse

Giant cell tumor of bone (GCTB) is a common primary neoplasm of bone characterized by distinctive clinicopathological features. GCTB is exceedingly rare in nonhuman species, and it has been sporadically reported in cats, dogs, rats, and birds. This report describes a primary murine bone tumor that shares striking clinicopathological similarities with human GCTB. The neoplasm occurred in a 71-week-old C57BL/6 mouse heterozygous for the specific Trp53 R172H point mutation. Grossly, the tumor presented as a mono-ostotic nodular mass arising from the distal metaphysis of the right femur. Microscopically, the affected bone was effaced by an osteolytic neoplasm with focal infiltrations into the surrounding tissues. Similarly to what was reported for human GCTB, the murine neoplasm consisted of 3 main cell populations: (1) bundles of pleomorphic spindle-shaped mononuclear cells displaying an indefinite mesenchymal histogenesis with immunohistochemical expression of vimentin and smooth muscle actin, (2) scattered multinucleated giant cells exhibiting osteoclast differentiation with prominent tartrate-resistant acid phosphatase activity and immunoreactivity for monocyte/macrophage markers including CD45 and lysozyme, and (3) scattered round mononuclear cells consistent with activated macrophages and expressing CD45, lysozyme, and F4/80. Based on these morphological and immunohistological results, the murine bone tumor described in this study has been putatively classified as GCTB.

Clinicopathologic profile of 470 giant cell tumors of bone from a cancer hospital in western India

Over 20 years, 470 cases of giant cell tumor of bone diagnosed at a tertiary cancer hospital were analyzed. Male predominance (57%), predilection for bones around the knee joint (42%), and occurence in the 21- to 30-year-old age group (49.1%) with 6% being in the immature skeleton are well known facts. Accurate diagnosis was possible in 66% and 88% of cases on radiology and biopsy, respectively. Tumors measured 6 to 20 cm and, in 402 cases, showed "usual" histology comprising uniformly scattered multinucleate giant cells amidst mononuclear stromal cells, together imparting a syncitium-like appearance. Presence of osteoid, hemorrhage, and aneurysmal bone cyst-like areas; spindle cells in sheets (devoid of giant cells); or storiform pattern and intravascular osteoclasts were less common. The less common histologic features posed diagnostic difficulty in the setting of a small biopsy. Treatment included intralesional curettage (33.19%), marginal excision (4.2%), wide excision (31%), or radical surgeries (14.25%). Recurrences seen in 170 cases were multiple in 47 cases. Metastases largely to the lung were recorded in 24 cases. The histology of all the tumors, namely, primary, recurrent, or metastatic was identical. Statistical analysis using the computer software SPSS (SPSS Inc, Chicago, Ill)was performed with particular reference to the unusual histologic features vs recurrence and metastasis by chi(2) test. The only statistically significant factors were occurrence in the axial skeleton vs appendicular skeleton (P = .001) and primary treatment elsewhere vs at this hospital (P = .045), each of these being associated with increased frequency for local recurrence but not metastasis.

Giant cell reparative granuloma of the temporal bone: neuroradiological and immunohistochemical findings

A 38-year-old man presented with a giant cell reparative granuloma (GCRG) of the left temporal bone. Computed tomography showed a osteolytic middle cranial mass lesion. Magnetic resonance (MR) imaging showed the lesion as low intensity with heterogeneous enhancement by gadolinium on the T1-weighted images, and extremely low intensity on the T2-weighted images. Angiography showed the lesion as highly vascular and fed by branches of the left external carotid artery. After preoperative embolization, gross total removal of the tumor was performed. The postoperative course was uneventful and no evidence of recurrence has been found for more than 4 years. Histological examination revealed GCRG with multinucleated giant cells in the fibrous background, abundant collagen bundles, hemosiderin deposits, and trabeculae of reactive bone. Some of the mononuclear stromal cells and almost all of the giant cells were positive for CD68, suggesting histiocytic differentiation. These histological features reflect the marked decrease in signal intensity on T2-weighted MR images.

Primary giant cell tumor of soft tissue

BACKGROUND

Primary giant cell tumor of soft tissue, also known as soft tissue giant cell tumor of low malignant potential, is a rare soft tissue tumor located in both superficial and deep soft tissue. Histologically, these lesions bear a close resemblance to their bony counterparts, giant cell tumor of bone, with round to spindle-shaped cells intimately admixed with uniformly scattered osteoclast-like multinucleated giant cells. In 1989 in the dermatology literature, two malignant giant cell tumors of soft parts were described that filled the dermis and extended into the subcutaneous tissue.

METHODS

The authors report the rare occurrence of a giant cell tumor of soft tissue occurring primarily in the dermis that lacks overtly malignant features and clinically was thought to be an epidermal inclusion cyst.

RESULTS

Light microscopy revealed a non-encapsulated cellular dermal tumor containing numerous osteoclast-like giant cells. Cytologic atypia was minimal and the mitotic count averaged 2-3/10 HPF. The histologic differential diagnosis is also discussed.

CONCLUSION

Giant cell tumor of soft tissue is a rare neoplasm of the skin, however, recognition of this tumor is important due to its behavior as a low-grade malignancy.

Primary giant cell tumor of soft tissues similar to bone giant cell tumor: A case report and literature review

In this report we describe a primary giant cell tumor (GCT) of soft tissues located in the left dorsal wrist of a 52-year-old man. Plain radiographs did not reveal any lesion in his carpal or hand bones. Although the tumor was clinically considered a ganglion initially, the microscopic features were identical to those found in classic GCT of bone. Light microscopy showed a lesion composed of a homogeneously mixed proliferation of spindle and polygonal mononucleated stromal cells and evenly distributed multinucleated, osteoclast-like giant cells. Whereas most bone tumors have an extraosseous counterpart, only 13 cases of GCT in soft tissues had been published until 1998. Moreover, 64 new cases have been reported in three series. Nevertheless, most major reviews and textbooks do not consider this tumor as a specific entity and regard it as a low grade variant of malignant GCT of soft tissue. We describe the clinical, histologic, and immunohistochemical features of this rare benign neoplasm emphasizing the differential diagnosis with its malignant soft tissue counterpart, an ominous tumor.

Primary giant cell tumor of soft tissues: a study of 22 cases

Twenty-two cases of giant cell tumor of soft tissues (GCT-ST) identified in the Mayo Clinic files and the consultation files of two of the authors (A.G.N., C.D.M.F.) were analyzed clinicopathologically. Age at presentation ranged from 5 to 80 years (median, 43 years), and there was no sex predilection (12 male, 10 female). Duration of symptoms ranged from 2 to 12 months (median, 4.5 months), and a painless growing mass was the most common complaint. The lower limbs were the most frequent location (50%), followed by the trunk (31.8%) and the upper limbs (13.6%). The size of the tumors ranged from 1 to 10 cm, and they tended to be superficial (86.4%), forming well-circumscribed (72.7%), multinodular (86.4%) masses. Histologically, all tumors consisted of a mixture of mononuclear cells showing vesicular, round to oval nuclei and osteoclastlike, multinucleated giant cells distributed uniformly throughout the tumors. Foci of stromal hemorrhage were observed in 11 tumors (50%); nine tumors (40.1%) showed metaplastic bone formation and six (27.2%) showed aneurysmal bone cystlike areas. Necrosis was absent in all but one tumor. Mitotic figures were present in all but one tumor, ranging from two to more than 30 mitoses per 10 high-power fields (HPFs; median, 9.5 mitoses per 10 HPFs) and were typical in aspect. Vascular invasion was identified in seven tumors (31.8%), and none of the tumors showed marked cellular atypia or pleomorphism. The tumors were treated surgically, and follow-up information was available for 16 patients (duration of follow-up, 2 to 130 months; median, 51 months). Only one of the 16 patients (6.2%) had local recurrence and lung metastases; this patient died of the tumor. In conclusion, GCT-ST occurs as a primary soft-tissue neoplasm and is identical clinically and morphologically to giant cell tumor of bone. Provided that GCT-ST is treated adequately by complete excision, a benign clinical course is expected because episodes of distant metastasis and tumor-associated death seem to be exceedingly rare.

Telomeric fusion is a major cytogenetic aberration of giant cell tumors of bone

Giant cell tumor of bone (GCT) is regarded as a rare primary bone neoplasm derived from stromal cells, which have the ability to recruit and harbor macrophage and multinucleated osteoclast-like giant cells. Despite being often considered benign, GCT is a problematic neoplasm in that it is aggressive, unpredictable and difficult to treat effectively. Cytogenetically GCT is characterised by a high frequency of telomeric fusion, a process which has been implicated in the production of chromosome instability and tumorigenesis. To extend our knowledge of the significance of telomere association in GCT, the cytogenetics of cell lines derived from spindle-shaped stromal-like mononuclear cells (the tumor cells) of GCT was investigated. Cell lines from three different patients showed telomeric association in all passages. The rate of telomeric association varied from line to line and from passage to passage, but there was no particular pattern to the variations. Many other cytogenetic abnormalities were seen as well as telomeric association, but these were rarely clonal. The nature of most of the other abnormalities seen, such as deleted chromosomes and chromosomes with additional unidentifiable material, was consistent with their being formed as a result of breakage of the dicentric fused chromosomes at a telophase. Chromosomes 13, 14 and 21 were most commonly involved in telomeric fusion. It appears that telomeric association persists in long-term cultures of GCT and is responsible for the accumulation of other associated cytogenetic aberrations. Telomeric reduction and telomerase activity may act as oncogenic events, promoting and sustaining the transformed GCT phenotype.