Differentiation of giant cell tumours of bone, primary aneurysmal bone cysts, and aneurysmal bone cysts secondary to giant cell tumour of bone: using whole-tumour CT texture analysis parameters as quantitative biomarkers.

AIM: To determine whether computed tomography (CT) texture analysis parameters can be used as quantitative biomarkers to help differentiate giant cell tumour of bones (GCTs), primary aneurysmal bone cysts (PABCs), and aneurysmal bone cysts (ABCs) secondary to giant cell tumours of bone (GABCs). MATERIALS AND METHODS: One hundred and seven patients with 63 GCTs, 31 PABCs, and 13 GABCs were analysed retrospectively. All patients underwent preoperative CT. Two radiologists independently evaluated the qualitative features of the CT images and extracted texture parameters. Patient demographics, qualitative features, and texture parameters among GCTs, PABCs, and GABCs were compared statistically. Differences in these parameters between ABCs and GCTs were also assessed. ROC curves were obtained to determine optimal parameter values. RESULTS: The best preoperative CT parameters to differentiate GCTs, PABCs, and GABCs included one qualitative feature (location around the knee) and four texture parameters (95th percentile, maximum intensity, skewness, and kurtosis). Age and three texture parameters (5th percentile, inhomogeneity, and kurtosis) enabled statistically significant differentiation between GCTs and ABCs. Combination of the above four parameters generated the largest area under the ROC curve (AUC) for the differentiation of GCTs and ABCs. CONCLUSION: CT texture analysis parameters can be used as quantitative biomarkers for preoperative differentiation among GCTs, PABCs, and GABCs.

Incidence and progression of osteoarthritis following curettage and cementation of giant cell tumor of bone around the knee: long-term follow-up.

BACKGROUND: Giant cell tumor of bone (GCTB) is a benign locally aggressive tumor frequently treated with intralesional curettage and cementation. The aim of this study was to investigate the long-term incidence of arthritic changes following curettage and cementation of GCTB around the knee. MATERIALS AND METHODS: This study was a retrospective review of patients with GCTB around the knee treated with curettage and cementation with a minimum follow-up of 10 years. The functional results were assessed using the Musculoskeletal Tumor Society (MSTS) score. The arthritic changes were classified using the Kellgren-Lawrence (KL) classification system of osteoarthritis. RESULTS: This study included 119 patients, 54 males and 65 females, with a mean age of 29.4 ± 9.2 years. There were 35 (29.4%) patients with pathological fractures. There were 84 (70.6%) patients with de novo lesions and 35 (29.4%) with recurrent lesions. The mean follow-up period was 13.2 ± 3.16 years. The mean MSTS score was 28.5 ± 1.9. Overall, 25 (21%) patients developed variable degrees of arthritis of KL grade 1 (n = 7), KL grade 2 (n = 11), KL grade 3 (n = 4), and KL grade 4 (n = 3). Ten patients showed progression of arthritis during the follow-up period. Age at presentation, gender, presence of pathological fracture, whether the tumor was de novo or recurrent, and tumor location were not associated with arthritis incidence. CONCLUSIONS: Curettage and cementation can be used safely to treat GCTB around the knee. Arthritis of the knee is a possible complication, but mild grades are expected in most cases. There was no association between arthritis incidence and age, gender, pathological fractures, tumor location, or recurrent tumors. LEVEL OF EVIDENCE: Level IV.

Huge aneurysmal bone cyst secondary to giant cell tumor of the hand phalanx: a case report and related literature.

BACKGROUND: Aneurysmal bone cyst (ABC) secondary to Giant Cell Tumor of bone (GCT) is a rare lesion, of which the incidence is about 0.011 to 0.053 per 100,000 every year. There are only a few previous case reports, and most of them occur in the spine, long bones or flat bones. CASE PRESENTATION: We report one case of a patient who complained of "progressive enlargement of the mass on right-hand fifth finger for 5 years with ulceration for 6 months". After the imaging examination in our hospital, it was diagnosed as a "huge bone tumor on the proximal phalanx of the right-hand fifth finger", then wide excision and amputation of the fifth finger were made. The pathological examination diagnosed the mass as aneurysmal bone cyst secondary to giant cell tumor, 13 × 8 × 6 cm3, with no local infiltration observed. No recurrence and metastasis occurred 18 months after the operation, and the patient recovered well. CONCLUSION: In this report, we discuss the etiology, diagnosis, differentiation, and management of Aneurysmal bone Cyst secondary to Giant Cell Tumor of bone, and review previous case studies.

Role of (Neo)adjuvant Denosumab for Giant Cell Tumor of Bone.

OPINION STATEMENT: Denosumab is a RANK ligand inhibitor approved for the treatment of giant cell tumor of bone. While the role of denosumab in the setting of advanced and unresectable disease is well established, its role in surgically resectable disease is currently under discussion. Several prospective and retrospective series on neoadjuvant therapy in potentially resectable tumor with high morbidity surgery reported a relapse rate of 10-20% after resection and 30-40% after curettage. At the same time, less morbid surgery has obvious clinical advantages for the patient, and several studies have shown the efficacy of denosumab in downgrading of the surgical procedure. Currently, the role of neoadjuvant denosumab in operable GCTB is limited to selected cases in which a diffuse reactive bone formation and peripheral ossification can make an easier surgical procedure, for example, in tumors with a large soft tissue component. A planned resection may become less morbid when preoperative denosumab is administered. Whenever a segmental resection is thought to be indicated at diagnosis, denosumab may be considered in the neoadjuvant setting. A preoperative course of 6 months is considered safe and effective. Two case scenarios are presented and critically discussed. Because of the high recurrence rates after denosumab treatment followed by curettage, we discourage the use of denosumab when curettage is considered feasible. In this setting, a short course of preoperative denosumab (2-6 months) may be considered for highly selected cases, for example in pathological fractures. The role of adjuvant denosumab needs further investigation. Long-term disease control has been reported in case of non-surgical lesions, even after treatment interruption, but there is no consensus on ideal treatment duration and dosage for these scenarios. In all cases, multidisciplinary discussion with oncology, pathologist, radiologist, and surgeons is mandatory. Patient's comorbidities, dental conditions, and preferences, including family planning, should always be taken into account.

Residual bone fragments in tibiofibular joint and postoperative local recurrence: an analysis of 21 cases of proximal fibular giant cell tumour.

BACKGROUND: Currently, there are no known reports on the aetiology of local giant cell tumour (GCT) recurrence in the proximal fibula following en bloc resection. We analysed 21 cases of proximal fibular GCT, focusing on the presence of residual bone in the tibiofibular joint, its causes and its impact on postoperative recurrence. METHODS: We retrospectively analysed 21 cases with proximal fibular GCT occurring between 2000 and 2017. RESULTS: There were 14 males and 7 females. The average patient age was 25.0 years. Seventeen patients were diagnosed and treated at our facility, while 4 were referred after local recurrence. Six patients presented with residual bone fragments in the tibiofibular joint during their first month of follow-up. Patients with residual bone fragments had a higher local recurrence rate (83.3%) than those without (0%, p = 0.0003). Upon further analysis, patients with a preoperative Campanacci grade III tumour (p = 0.0055) and pathological fractures (p = 0.0109) were at a higher risk of exhibiting postoperative residual bone fragments. CONCLUSIONS: The presence of residual bone fragments in the tibiofibular joint was the main cause of postoperative local recurrence. The presence of residual bone fragments may be related to the preoperative Campanacci grade and pathological fractures. Therefore, close attention should be paid to postoperative follow-up examinations, and if recurrence is suspected, surgical resection should be planned.

Use of warm Ringer's lactate solution in the management of locally advanced giant cell tumor of bone.

BACKGROUND: This study was conducted to discover the effectiveness and safety of using warm Ringer's lactate solution (RLS) as a local treatment in the management of locally advanced giant cell tumor of bone with marked soft tissue invasion, including nearby neurovascular bundles. PATIENTS AND METHODS: This was a longitudinal cohort study with an average follow-up period of 4.6 ± 0.3 years, ranging from 4.2 to 5.9 years. There were 21 patients (9 male and 12 female), with the ages of subjects ranging from 12 to 64 years. Eight patients (38 %) were tumor recurrence cases. Pathological fracture was found in 15 patients (71 %). After extended curettage, warm RLS (50 °C) was locally applied for 20 min. Bone stabilization and reconstruction were then performed. RESULTS: All patients survived the operation. No additional neurovascular injury resulting from the use of warm RLS was found. Patients who had neurological deficit before the operation experienced significant improvement in motor and sensory function during the follow-up period. Complication was found in one patient (5 %). Two patients (9.5 %), had tumor recurrence and 19 patients (90.5 %) were tumor-free with good to acceptable function. CONCLUSION: Use of warm Ringer's lactate solution as an adjunctive local treatment during intra-lesional curettage of giant cell tumor with locally soft tissue extension was found to be safe with relatively low recurrence rate. However, additional studies to identify the optimum thermoablation dose at each part of the body should be undertaken before this technique can be used as a standard treatment.

Surgery methods and soft tissue extension are the potential risk factors of local recurrence in giant cell tumor of bone.

BACKGROUND: Various treatments of giant cell tumor of bone (GCTB) included in curettages and resections and with adjuvant are exerted, but the best treatment is controversial. The aim of the study was the identification of individual risk factors after various treatments in GCTB. METHODS: A total of 179 patients treated for GCTB between 1998 and 2010 were concluded in the retrospective study. All patients were treated with intralesional curettage, extensive curettage, or wide resection. Mean follow-up was 60.2 ± 18.7 months (36~112 months). Age, gender, tumor location, Campanacci grade, soft tissue extension, pathological features, and surgical methods were performed to univariate Kaplan-Meier survival analysis and multivariate Cox regression analysis. RESULTS: The local recurrence rates of intralesional curettage (41.9%) and extensive curettage (19.0%) were significantly higher than that of wide resection (7.7%). The higher risk of local recurrence was found for soft tissue extension (hazard = 7.921, 95% CI 1.107~56.671), compared with no statistical significances between gender, location, Campanacci grade, pathologic fracture, and local recurrences, which were shown by Kaplan-Meier analysis. However, recurrence-free survival (RFS) of patients younger than 30 was significantly lower than that of patients older than 30. The RFS of pathologic fracture patients with soft tissue extension was significantly lower than that of pathologic fracture patients without soft tissue extension. Multivariate Cox regression analysis indicated that the independent variable that contributed to recurrence-free survival was soft tissue extension and surgical methods. The RFS of extensive curettage had no statistically significant difference with wide resection and was significantly higher than that of intralesional curettage. Use of high-speed burring and bone cement significantly decreased the local recurrence rate. CONCLUSIONS: Age (below 30 years), gender, tumor location, Campanacci grade, and pathologic fracture have no statistically significant influence on local recurrences. Soft tissue extension and intralesional curettage of surgical methods increased the RFS. The results of the present study suggested that compared with curettage and wide section, treatment of GCTB by extensive curettage could provide the favorable local control and functional recovery.

Significance of ß-catenin expression for the incidence of pathological fractures in giant cell tumors of bone.

Aim of the study is to determine the possible roles of p53, cyclin D1, ß-catenin and Ki-67 in the increase in risk of fractures in patients with giant cell tumor of bone. The study included a total of 164 patients with giant cell tumor of bone (GCTB), 21 (12.8%) with and 143 (87.2%) without fracture. The samples were analyzed immunohistochemically for expression of Ki-67, p53, cyclin D1 and ß-catenin. According to the immunohistochemical expression of p53 and Ki 67 in mononuclear stromal cells, as well as of cyclin D1 in multinuclear giant cells, there was no significant association with immunopositivity and risk of fractures. However, our research revealed that patients with cytoplasmic expression of b-catenin in stromal cells had three times more frequent occurrence of pathological fractures, which was highly statistically significant (χ2 = 7.065; p = 0.008). Moreover, a highly statistically significant correlation between the nuclear expression of ß-catenin in giant cells and the incidence of pathological fractures was also found (χ2 = 8.824; p = 0.003). The study showed that ß-catenin expression highly correlates with the incidence of pathological fractures in patients with GCTB. Taking into account that ß-catenin is closely linked to activation of the Wnt signaling pathway in GCTB pathogenesis, one could postulate that activation of the Wnt pathway is one of the contributing factors to locally destructive behavior of this tumor, as well as to the incidence of pathological fractures.

Prognostic value of p53 protein expression in giant cell tumor of bone.

Giant cell tumor of bone (GCTB) is a benign tumor with a tendency for local recurrence. GCTB may cause lung metastases, and secondary malignant GCTB is rare. Its histological appearance does not predict local aggressiveness and/or the metastatic potential of the tumor. We aimed to investigate the prognostic value of the Ki-67 proliferative index and p53 protein expression in GCTB in predicting local recurrence, lung metastasis, and malignant transformation. We retrospectively reviewed 42 cases of GCTB. The p53 expression was positive in 20 cases. We used 10% as a cut-off value for p53 expression. In 10 cases, there were local recurrences. Lung metastases were found in three cases and malignant transformation was found in one case with classical GCTB located in the sacrum three years following diagnosis. The Ki-67 index was higher in cases with recurrence, but this difference was not statistically significant. Of the recurrent cases, two had no p53 staining while eight had moderate-to-strong staining. The staining was usually weakly positive in the non-recurrent cases. In conclusion, we believe that p53 may be used as a marker for the biological behavior of GCTB.

Effects of denosumab on pain and analgesic use in giant cell tumor of bone: interim results from a phase II study.

BACKGROUND: Giant cell tumor of bone (GCTB) is an aggressive primary osteolytic tumor. GCTB often involves the epiphysis, usually causing substantial pain and functional disability. Denosumab, a fully human monoclonal antibody against receptor activator of nuclear factor κΒ ligand (RANKL), is an effective treatment option for patients with advanced GCTB. This analysis of data from an ongoing, open-label study describes denosumab's effects on pain and analgesic use in patients with GCTB. MATERIAL AND METHODS: Patients with unresectable disease (e.g. sacral or spinal GCTB, or multiple lesions including pulmonary metastases) were enrolled into Cohort 1 (N = 170), and patients with resectable disease whose planned surgery was associated with severe morbidity (e.g. joint resection, limb amputation, or hemipelvectomy) were enrolled into Cohort 2 (N = 101). Patients received denosumab (120 mg) subcutaneously every four weeks, with additional doses on study days 8 and 15. Patients assessed worst pain severity with the Brief Pain Inventory - Short Form (BPI-SF) at baseline, at each visit for the first six months, and every three months thereafter. RESULTS: Clinically relevant pain improvement was reported by 29% of patients in Cohort 1 and 35% in Cohort 2 during week 1 and by ≥ 50% of patients in each cohort at each study visit from months 2-30. Median time to clinically relevant improvement was 30 (95% CI 16, 57) days in Cohort 1 and 15 (95% CI 15, 29) days in Cohort 2. Results in patients with moderate/severe pain at baseline were similar. Fewer than 30% of patients in Cohort 1 and 10% in Cohort 2 experienced clinically relevant pain worsening at any visit through 27 months. Most patients had no/low analgesic use during the study. CONCLUSION: Most patients treated with denosumab experienced clinically relevant decreases in pain within two months.

Giant cell tumor of bone with secondary aneurysmal bone cyst-like change producing ß-human chorionic gonadotropin.

Giant cell tumor of bone is a benign, locally aggressive neoplasm that is composed of sheets of neoplastic mononuclear cells interspersed amongst non-neoplastic, uniformly distributed, osteoclast-like giant cells. They represent approximately 4-5% of primary bone tumors. Rarely, bone tumors have been noted to produce human chorionic gonadotropin, a finding most often reported in osteosarcoma. We present the case of a young woman who presented with a low-level human chorionic gonadotropin level which, after resection of her recurrent giant cell tumor of bone with secondary aneurysmal bone cyst-like change, became undetectable in her blood. Furthermore, cells within the aneurysmal bone cyst component were immunohistochemically positive for ß-human chorionic gonadotropin. This is the first report of such a finding in the literature.

[Opioid combination of transdermal fentanyl and oral oxycodone for pain in a patient with giant-cell tumor of the sacrum].

We describe successful pain control in a patient suffering from severe pain, using an opioid combination of transdermal fentanyl and oral oxycodone. A woman in her 40s with a giant-cell tumor of the sacrum suffered from refractory 4-5/5 pain on the Wong-Baker faces pain rating scale in her sacrum, feet and legs. Despite administration of fentanyl (2,520 microg day(-1)), she could not sleep in the supine position due to pain and dysesthesia. We gradually changed her medication from transdermal fentanyl to oral oxycodone. However, the patient complained of constant drowsiness after the complete switch to oral oxycodone (120 mg x day(-1)). Hence, we reduced the oral oxycodone dose and began a combination of transdermal fentanyl and oral oxycodone in addition to increasing doses of pregabalin. With the combination of transdermal fentanyl (25 microg x hr(-1)) and oral oxycodone (60 mg x day(-1)) her pain decreased to 1-3/5 on the faces pain rating scale. Our experience suggests that an opioid combination may provide favorable pain control in patients with severe pain, while minimizing the side effects of each drug.

Giant cell tumor of bone: review, mimics, and new developments in treatment.

Giant cell tumor (GCT) of bone is generally a benign tumor composed of mononuclear stromal cells and characteristic multinucleated giant cells that exhibit osteoclastic activity. It usually develops in long bones but can occur in unusual locations. The typical appearance is a lytic lesion with a well-defined but nonsclerotic margin that is eccentric in location, extends near the articular surface, and occurs in patients with closed physes. However, GCT may have aggressive features, including cortical expansion or destruction with a soft-tissue component. Fluid-fluid levels, consistent with secondary formation of aneurysmal bone cysts, are seen in 14% of cases. GCT can mimic or be mimicked by other benign or malignant lesions at both radiologic evaluation and histologic analysis. Rarely, GCT is associated with histologically benign lung metastases or undergoes malignant degeneration. In the past, the mainstay of treatment was surgical, primarily consisting of curettage with cement placement, with recurrence rates of 15%-25%. Recurrence is suggested by development of progressive lucency at the cement-bone interface. Other complications include pathologic fracture and postoperative infection. Denosumab, a monoclonal antibody that targets the osteoclastic activity of GCT, has produced 90% tumor necrosis in early studies, results indicative of promise as a potential adjuvant therapy.

Giant cell tumor with pathologic fracture: should we curette or resect?

BACKGROUND: Approximately one in five patients with giant cell tumor of bone presents with a pathologic fracture. However, recurrence rates after resection or curettage differ substantially in the literature and it is unclear when curettage is reasonable after fracture. QUESTIONS/PURPOSES: We therefore determined: (1) local recurrence rates after curettage with adjuvants or en bloc resection; (2) complication rates after both surgical techniques and whether fracture healing occurred after curettage with adjuvants; and (3) function after both treatment modalities for giant cell tumor of bone with a pathologic fracture. METHODS: We retrospectively reviewed 48 patients with fracture from among 422 patients treated between 1981 and 2009. The primary treatment was resection in 25 and curettage with adjuvants in 23 patients. Minimum followup was 27 months (mean, 101 months; range, 27-293 months). RESULTS: Recurrence rate was higher after curettage with adjuvants when compared with resection (30% versus 0%). Recurrence risk appears higher with soft tissue extension. The complication rate was lower after curettage with adjuvants when compared with resection (4% versus 16%) and included aseptic loosening of prosthesis, allograft failure, and pseudoarthrosis. Tumor and fracture characteristics did not increase complication risk. Fracture healing occurred in 24 of 25 patients. Mean Musculoskeletal Tumor Society score was higher after curettage with adjuvants (mean, 28; range, 23-30; n = 18) when compared with resection (mean, 25; range, 13-30; n = 25). CONCLUSIONS: Our observations suggest curettage with adjuvants is a reasonable option for giant cell tumor of bone with pathologic fractures. Resection should be considered with soft tissue extension, fracture through a local recurrence, or when structural integrity cannot be regained after reconstruction. LEVEL OF EVIDENCE: Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Clival giant cell tumor presenting with isolated trigeminal nerve involvement.

Giant cell tumour (GCT) constitutes about 5 % of all skeletal tumors. They rarely occur in the skull. When involved, they preferentially involve the sphenoid or temporal bones. Skull-base GCTs generally present with multiple cranial nerves involvement, most commonly sixth followed by the third cranial nerve. We describe a case of clival GCT presenting with an isolated trigeminal nerve involvement in a 19-year-old man which was managed by surgery and adjuvant radiation. At 18 months of follow-up, the patient is clinically asymptomatic. Clival GCT should also be considered in the differential diagnosis of any isolated trigeminal nerve palsy. Adjuvant radiation has an important role to play in managing this tumour.

[Surgical treatment for long bone giant cell tumor of extremity with pathologic fracture].

OBJECTIVE: To identify the clinical features of patients with giant cell tumors (GCT) of long bones in extremities presented with pathological fracture (PF), and discuss the surgical strategy with retrospective analysis and literature review. METHODS: We searched medical electronic records from January 1999 to December 2011 in our hospital to identify patients with definite diagnosis of extremity GCT presented with PF. Clinical data including gender, tumor site, age, surgical treatment option, postoperative complication, limb function, local recurrence and pulmonary metastasis were collected and analyzed statistically. The t-test and chi-square test were used for continuous and dichotomous variables, respectively. RESULTS: Between 1999 and 2011 we treated 201 patients with GCT in extremities (long bone only: femur, tibia, fibula, humerus, ulna, and radius), 33 of whom presented with a PF. The gender ratio was 1.06 for a male predominance. The median age was 33 (15-62), and the most common site of pathologic fractures was distal femur (n=17), followed by proximal tibia (n=5), proximal femur (n=5), proximal humerus (n=4), and distal radius (n=2). Nine fractures were intra-articular. The tumors were treated by extended curettage (n=11) or en bloc excision (n=22), and the fractures were reconstructed by endoprosthesis (n=20), autologous iliums graft combined with synthetic bone substitutes (n=7), acrylic cementing (n=3), autologous fibula graft (n=2), or allograft (n=1). Ten operations were followed by complications of any kind, where implant failure and recurrence were the commonest, and re-operation rate was 27.3%. The mean functional score according to the scoring system of the Musculoskeletal Tumor Society (MSTS) was 81% in patients who received endoprosthesis replacement and 82% in other reconstruction options. CONCLUSION: Extended curettage and en bloc resection were all considered to be the effective treatment options for patients with extremity GCT presented with PF. However, local recurrence and implant related complication were the major concern for joint reservation and prosthetic replacement, respectively.

Microwave in situ inactivation in the treatment of bone giant cell tumor: a mid-term descriptive study.

AIM: To evaluate the mid-term clinical efficacy of microwave in situ inactivation combined with bone grafting or polymethyl methacrylate (PMMA) filling in the treatment of giant cell tumor of bone (GCTB). METHODS: This is a retrospective, descriptive, and analytical study. A total of 30 GCTB patients received microwave in situ inactivation from January 2012 to January 2020, whose clinical recurrence rate was evaluated at the last follow-up after microwave in situ inactivation surgery. The Musculoskeletal Tumor Society (MSTS) function score was used to evaluate the postoperative clinical panoramic results. RESULTS: All patients were followed up for 21 to 110 months, with an average of 63.79 months. Distal femur (40%) and proximal tibia (28%) had a higher rate of GCTB incidence. Seventeen percent of tumor patients suffered from associated pathologic fracture. The rate of Campanacci classification stage III was 60%. The average MSTS score was evaluated as 27.53 points overall at the last follow-up. In terms of complications, three, two, two and one cases developed fat liquefaction, controllable tissue rejection reaction, incision infection and degenerative changes around lesion joint, respectively, without in situ recurrences and reoperation as well as distant lung metastasis. CONCLUSIONS: The method of microwave in situ inactivation combined with bone grafting or PMMA filling is prudently recommended as one of the options for the limb salvage treatment of giant cell tumor of long and periarticular bone. LEVEL OF EVIDENCE: IV: case series.

Brown tumor of the cervical spine with primary hyperparathyroidism: A case report and literature review.

RATIONALE: Brown tumor (BT), an uncommon focal lytic bone tumor, is a non-neoplastic and reactive process caused by increased osteoclastic activity and fibroblastic proliferation in primary or secondary hyperparathyroidism. Vertebral tumor causing neural compression is relatively rare, especially in the cervical spine. PATIENT CONCERNS: A 29-year-old man developed neck pain and arm radicular pain 4 months ago, with the level of serum calcium significantly higher than normal. Computed tomography scan of the cervical spine revealed an expansile lytic lesion occupying the C6 body, left pedicle, and left lamina of C5-6. DIAGNOSES: Osteoclastoma according to imaging and histopathological results. INTERVENTIONS: A laminectomy of C5-6 was performed. OUTCOMES: One month later, he was re-hospitalized due to nausea and vomiting and the serum calcium, was still, kept at a high level. Additionally, the parathormone (PTH) was greatly higher than normal. BT with primary hyperparathyroidism due to the parathyroid tumor was considered. After the surgery of the right parathyroid gland was performed, serum calcium and PTH both decreased, and computed tomography showed good recovery. LESSONS: BTs might be misdiagnosed as other giant cell tumors, thus when giant cell tumors are considered, serum calcium and PTH examination may be needed to exclude BTs.

[Giant cell tumor of the ribs that required emergency surgery due to massive hemothorax; report of a case].

A 63-year-old man with a left rib tumor, which had been diagnosed as a giant cell tumor 2 years previously, had been followed up at another hospital after embolization of a feeding artery of the tumor. He was admitted to the emergency room of our hospital with complaints of breathing difficulties. A chest computed tomography (CT) revealed a left chest wall tumor, about 11 cm in size, originating from the 8th rib and a massive left hemothorax. Emergency operation was performed to releave hemorrhagic shock. Bleeding from the tumor was confirmed at thoracotomy. Tumor was removed with combined resection of the adjacent chest wall and diaphragm. His postoperative course was uneventful and he was discharged on the 8th postoperative day.

Articular degeneration after subchondral cementation for giant cell tumors at the knee.

PURPOSE: To quantify joint degeneration and the clinical outcome after curettage and cementation in subchondral giant cell tumors of the bone (GCTB) at the knee. METHODS: We conducted a retrospective analysis of 14 consecutive patients (seven female, seven male) with a mean age of 34 years (range 19-51) who underwent curettage and subchondral cementation for a biopsy-confirmed GCTB at the distal femur or the proximal tibia between August 2001 and August 2017, with a mean follow-up period of 54.6 months (range 16.1-156 months). The Whole-Organ Magnetic Resonance Imaging Score (WORMS), Kellgren-Lawrence (KL) classification, and Musculo-Skeletal Tumor Society (MSTS) score were assessed. RESULTS: Radiological degeneration progressed from preoperative to the latest follow-up, with a median WORMS from 2.0 to 4.0 (p = 0.006); meanwhile, the median KL score remained at 0 (p = 0.102). Progressive degeneration (WORMS) tended to be associated with the proximity of the tumor to the articular cartilage (mean 1.57 mm; range 0-12 mm) (p = 0.085). The most common degenerative findings were cartilage lesions (n = 11), synovitis (n = 5), and osteophytes (n = 4). Mean MSTS score increased from 23.1 (preoperatively) to 28.3 at the latest follow-up (p < 0.01). Seven patients (50%) were treated for a local recurrence, with six revision surgeries performed. Removal of the cement spacer and filling of the cavity with a cancellous autograft was performed in seven patients. Conversion to a total knee arthroplasty was performed in one patient for local tumor control. CONCLUSIONS: Cementation following the curettage of GCTB around the knee is associated with slight degeneration at medium-term follow-up and leads to a significant reduction in pain. Removal of the cement and reconstruction with an autograft may be beneficial in the long term.