Sonographic features of diffuse giant cell tumor of the tendon sheath in the shoulder: A case report

A middle-aged woman presented to our hospital with a chief complaint of a mass on the left shoulder for 1 year. The initial lump was small with no pain or tenderness, and the patient had not sought medical attention for numbness in the left shoulder. Clinical examination showed a mass on the left shoulder measuring 11 × 8 × 3 cm approximately with no apparent skin damage or ecchymosis. No limitations in left shoulder joint movements were observed, and the patient exhibited normal movement of the left elbow joint, wrist joint, and metacarpophalangeal joint. Moreover, the left radial artery was palpable.

Xanthogranulomatous Epithelial Tumors and Keratin-Positive Giant Cell Rich Tumors of Soft Tissue and Bone: Two Sides of the Same Coin

Xanthogranulomatous epithelial tumor is a recently described soft tissue tumor characterized by subcutaneous location, partial encapsulation, a xanthogranulomatous inflammatory cell infiltrate, and keratin-positive mononuclear cells. It shares some morphologic features with keratin-positive, giant cell-rich soft tissue tumors. Both have recently been shown to harbor HMGA2::NCOR2 fusions. The relationship between these tumors and their differential diagnosis with other osteoclast-containing soft tissue tumors is discussed.

Pigmented villonodular synovitis/giant cell tumor in the knee

PURPOSE OF REVIEW

Pigmented villonodular synovitis (PVNS) is a rare diagnosis in pediatric patients and commonly presents with symptoms of swelling and pain. Early diagnosis is important to prevent secondary degeneration into the subchondral bone. This review will analyze the etiology, clinical signs/symptoms, diagnosis, treatment, and recent literature on PVNS in the pediatric population.

RECENT FINDINGS

Many theories of PVNS etiology have been described in the literature; however, an inflammatory response has been most widely accepted. PVNS can occur in any joint, but most commonly in the knee. The most common treatment for PVNS is synovectomy, and long-term follow-up is necessary to detect disease persistence or recurrence.

SUMMARY

Although uncommon, PVNS does occur in the pediatric population and this diagnosis should be included in the differential of atraumatic joint swelling and pain.

CSF1 expression in xanthogranulomatous epithelial tumor/keratin-positive giant cell-rich tumor

"Xanthogranulomatous epithelial tumor" (XGET) and "keratin-positive giant cell-rich soft tissue tumor" (KPGCT), two recently described mesenchymal neoplasms, likely represent different aspects of a single entity. Both tumors are composed of only a small minority of tumor cells surrounded by large numbers of non-neoplastic inflammatory cells and histiocytes, suggesting production of a paracrine factor with resulting "landscape effect," as seen in tenosynovial giant cell tumor. Recent evidence suggests that the paracrine factor in XGET/KPGCT may be CSF1, as in tenosynovial giant cell tumor. We hypothesized that CSF1 is overexpressed in XGET/KPGCT. To test our hypothesis, we performed quantitative real time PCR (qPCR) for CSF1 expression and CSF1 RNAscope chromogenic in situ hybridization (CISH) on 6 cases of XGET/KPGCT. All cases were positive with CSF1 CISH and showed increased expression of CSF1 by qPCR. Our findings provide additional evidence that the CSF1/CSF1R pathway is involved in the pathogenesis of XGET/KPGCT. These findings suggest a possible role for CSF1R inhibition in the treatment of unresectable or metastatic XGET/KPGCT.

Cytomorphologic panorama of giant cell tumour of tendon sheath

BACKGROUND

Giant Cell Tumour of Tendon Sheath (GCTTS) is a slow growing benign soft tissue tumour arising from synovium of tendon sheath or joint. These tumours occur more frequently in upper limbs, especially hands. In the present study, we aimed to evaluate the cytomorphological spectrum of GCTTS.

METHODS

This retrospective study includes a total of 56 cases of GCTTS diagnosed over a period of 8 years. The clinical and radiological details of these cases were retrieved from the cytopathology records and detailed cytomorphological features were studied and analysed. Histopathological correlation was done in 16/56 cases, where follow-up was available.

RESULTS

The mean age of patients at the time of presentation was 32 years and were predominantly females (68%). The most common site of GCTTS was fingers (76%), followed by foot, wrist and toes. The most consistent finding on cytology was stromal cells (100%) of polygonal, spindle and plasmacytoid morphology with interspersed multinucleated osteoclastic giant cells (100%), followed by binucleated stromal cells (75%), xanthoma cells (61%) and hemosiderin laden macrophages (52%). Presence of proteinaceous fluid background was also observed in 50% of the cases.

CONCLUSION

GCTTS can be diagnosed with certainty on FNAC based on characteristic cytomorphological features in an appropriate clinical and radiological setting. FNAC plays a pivotal role in diagnosing GCTTS and differentiating it from other giant cell rich lesions, thus obviating the need of tissue biopsy for diagnosis, which in turn helps the clinician in timely and adequate management of the patient.

Total en bloc spondylectomy of thoracic giant cell tumor with secondary aneurysmal bone cyst: case reports and review of literature

Spinal giant cell tumor (GCT) combined with secondary aneurysmal bone cyst (ABC) is a locally aggressive primary bone tumor. Total en bloc spondylectomy has never been reported to treat thoracic GCT combined with secondary ABC. We retrospectively reviewed two cases of spinal GCT combined with secondary ABC. A 41-year-old male patient was presented with back pain due to irregular expansive bone destruction involving the T6 vertebral body and intraspinal space-occupying lesion. Total en bloc spondylectomy of T6 vertebra was performed with good neurological status after the surgery. A 29-year-old female patient was presented with right scapular region pain due to irregular expansive bone destruction involving the T5 vertebral body and intraspinal space-occupying lesion. Total en bloc spondylectomy of T5 vertebra was performed with good neurological status after the surgery. Adjuvant radiation therapy was applied after the surgery without local recurrence at the 12-month or 24-month follow-up. Spinal GCT combined with secondary ABC appears to have a high local recurrence rate. Therefore, total en bloc spondylectomy should be applied to treat thoracic GCT combined with secondary ABC.

Bone SPECT/CT in Advanced Diffuse Tenosynovial Giant Cell Tumor of the Wrist

ABSTRACT

Tenosynovial giant cell tumor, previously known as pigmented villonodular synovitis, is a benign low-grade fibrohistiocytic proliferation with hemosiderin deposits in synovial joints. Mostly affecting the knee, it can also manifest in other synovial joints, infrequently also in the wrist. Tenosynovial giant cell tumor typically causes intense radionuclide uptake in all phases in planar bone scintigraphy, making a differentiation from other bone tumors or osteomyelitis difficult, especially in cases associated with extensive bone destruction. We present a case of an unusually advanced and extended tenosynovial giant cell tumor of the wrist in bone scintigraphy, SPECT/CT, radiograph, and MRI.

Keratin-positive giant cell-rich tumors of soft tissue with HMGA2::NCOR2 fusions

BACKGROUND

Giant cell tumor of soft tissue (GCT-ST) is a rare soft tissue neoplasm that is morphologically similar to but genetically distinct from giant cell tumor of bone. A novel keratin-positive GCT-ST (KPGCT-ST) harboring HMGA2::NCOR2 fusions was recently discovered. Fewer than 30 cases have been described; herein is reported an additional seven.

METHODS

Cases diagnosed as GCT-ST were retrieved from institutional archives and consultation files. The histopathologic characteristics were assessed, and the electronic medical record was reviewed.

RESULTS

Seven tumors were identified in six women and one man with a median age of 23 years. All patients underwent excision; no recurrences or metastases were noted during a median follow-up period of 7 months. Histopathologically, the tumors were characterized by a multinodular proliferation of keratin-positive mononuclear cells with evenly admixed osteoclast-like giant cells and absent neoplastic bone. A fibrous capsule with lymphoid cuffing was frequently seen. Foamy macrophages, inflammation, hemorrhage, and hemosiderin were variably present. The HMGA2::NCOR2 fusion was detected in all cases.

CONCLUSIONS

Our findings support previously reported hypotheses that KPGCT-ST is a spectrum of the same entity as the recently described xanthogranulomatous epithelial tumor. Although follow-up data are limited, to date, KPGCT-ST appears to follow an indolent course.

Partial sternectomy with reconstruction of a giant cell tumor of the sternum, a case report, Saudi, Arabia

BACKGROUND

Giant cell tumor (GCT) is a relatively common and locally aggressive benign bone tumor that rarely affects the sternum.

CASE PRESENTATION

We report a case of giant cell tumor of the sternum in a 28-year-old Saudi with painful swelling at the lower part of the sternum. Subtotal sternectomy and reconstruction with a neosternum using two layers of proline mesh, a methyl methacrylate prosthesis, and bilateral pectoralis muscle advancement flaps were performed.

CONCLUSIONS

Giant cell tumor of the sternum is a rare diagnosis. Surgical resection with negative margins is the ideal management. To avoid defects or instability of the chest wall, reconstruction of the chest wall with neosternum should be considered.

A Mass on the Sole Revealing a Giant-Cell Tumor of the Tendon Sheath

A 61-year-old woman presented with a 3-year history of painless soft-tissue mass on the right sole. The patient reported gradual growth, with a rapid increase in size over the past few months, leading to difficulty in walking. She had no history of past trauma. Examination revealed a 4-cm ovoid mass located over the ball of the foot. It was firm in consistency, with well-defined margins, a smooth surface, and an overlying normal skin (Figure 1). An ultrasound image revealed an eccentric, hypoechoic, nonvascular subcutaneous lobular mass. A magnetic resonance imaging (MRI) of the foot revealed a well-defined mass arising from the flexor tendon sheath of the right foot. The lesion was heterogeneously hyperin-tense on T1- and T2-weighted images with an avid contrast enhancement. All of the surrounding soft tissues indicated normal signal intensity patterns. There was no associated bony destruction. Histopathologic examination after complete excision of the mass established a well-circumscribed lesion composed of osteoclast-like giant cells and mononuclear cells in a hyalinized stroma, consistent with a giant cell tumor of the tendon sheath (GCT-TS) (Figure 2). There was no recurrence during a 6-month follow-up period (Figure 3).

Outcomes of Surgery for Benign Tumours in The Upper Extremity

Benign tumours of the upper extremity are common in hand surgeons' practice. The most commonly diagnosed are giant-cell tumours of the tendon sheath and lipomas.

THE OBJECTIVE

of this study was an investigation into the distribution of tumours in the upper limb, their symptomatology and outcomes of surgery, particularly regarding the rate of recurrence.

MATERIAL AND METHODS

A total of 346 patients, 234 women (68%) and 112 men (32%), who had undergone surgery for tumours located in the upper extremity which were not ganglion cysts were enrolled into the study. The follow-up assessment was performed at a mean of 21 months (range 12-36) post-operatively.

RESULTS

The most common tumour in this study was giant cell tumour of the tendon sheath - 96 cases (27.7%), followed by lipoma - 44 cases (12.7%). Most lesions - 231 (67%) were localized in the digits. A total of 79 (23%) recurrences were noted, the most common after surgery for rheumatoid nodules - 43.3% and the giant-cell tumours of the tendon sheath - 31.3%. The independent factors increasing risk of recurrence following the tumour's resection were: histological type of the lesion - the giant-cell tumour of the tendon sheath (p=0.0086) and the rheumatoid nodule (p=0.0027), as well as a combination of incomplete (non-radical) and not "en block" resection of tumours. A brief review of the literature referring to the presented material is offered.

Giant Cell Tumors With HMGA2::NCOR2 Fusion : Clinicopathologic, Molecular, and Epigenetic Study of a Distinct Entity

Giant cell tumors (GCTs) with high mobility group AT-Hook 2 ( HMGA2 )::nuclear receptor corepressor 2 ( NCOR2 ) fusion are rare mesenchymal tumors of controversial nosology, which have been anecdotally reported to respond to CSFR1 inhibitors. Here, we performed a comprehensive study of 6 GCTs with HMGA2::NCOR2 fusion and explored their relationship with other giant cell-rich neoplasms. Tumors occurred in 4 females and 2 males ranging in age from 17 to 32 years old (median 24). Three lesions originated in subcutaneous soft tissue and 3 in bone. Tumor size ranged from 20 to 33 mm (median 27 mm). The lesions had a nodular/multinodular architecture and were composed of sheets of mononuclear "histiocytoid" cells with uniform nuclei intermingled with multinucleated giant cells. Mitotic activity was low and nuclear atypia and metaplastic bone were absent. Variable findings included necrosis, cystic degeneration, lymphocytic infiltrate (sometimes forming nodules), and xanthogranulomatous inflammation. On immunohistochemistry, all cases focally expressed pan-keratin and were negative with SATB2 and H3.3G34W. Whole RNA-sequencing was performed in all cases of GCT with HMGA2::NCOR2 fusion and a subset of giant cell-rich tumors (tenosynovial-GCT, n = 19 and "wild-type" GCT of soft tissue, n = 9). Hierarchical clustering of RNA-sequencing data showed that GCT with HMGA2::NCOR2 fusion formed a single cluster, independent of the other 2 entities. Methylome profiling showed similar results, but the distinction from "wild-type" GCT of soft tissue was less flagrant. Gene expression analysis showed similar levels of expression of the CSF1/CSFR1 axis between GCT with HMGA2::NCOR2 fusion and tenosynovial-GCT, supporting their potential sensitivity to CSFR1 inhibitors. Clinical follow-up was available for 5 patients (range: 10 to 64 mo; median 32 mo). Three patients (60%) experienced local recurrences, whereas none had distant metastases or died of disease. Overall, our study confirms and expands previous knowledge on GCT with HMGA2::NCOR2 fusion and supports its inclusion as an independent entity.

Tenosynovial giant cell tumour of the finger: a case report

Giant cell tumour most commonly occuring in epiphysis of the long bone, present and with pain, tenderness and swelling. It is a solitary lesion with restricted movement and tenderness over the lesion. The tendon sheath is where tenosynovial giant cell tumours typically develop. Because of its remarkably peculiar position, we present a case of giant cell tumour (GCT) tenosynovial of bone in the middle phalaynx in a 33-year-old female with complaints of swelling, pain in ring finger of left hand since 2 months which is rarely seen. After clinical, radiological, pathological investigations tenosynovial giant cell tumour was diagnosed. Following fine needle aspiration cytology, histopathology was utilized to confirm the tumour's diagnosis which was later treated as resection of excision of the tumour with allo/autograft reconstruction. Our case report showed no evidence of recurrence in 2 years of follow-up. Hence our case report proves that early and complete resection of the tumour shows evidence of regain of complete range of motion and decrease recurrence rate.

Giant cell tumor of tendon sheath: A report of 216 cases

BACKGROUND

In this article on giant cell tumor of tendon sheath (GCTTS), we intend to summarize and analyze the clinical and pathological features of GCTTS hoping to improve clinical management and patient treatment.

METHODS

The study retrospectively reviewed 216 patients of GCTTS, registered at the Affiliated Hospital of Southwest Medical University from January 2010 to December 2020. These cases were diagnosed by surgical excision. The clinicopathological features and the prognosis were reviewed in the light of the current literature.

RESULTS

Of these 216 GCTTS patients, 72 were males (33.3%) and 144 females (66.7%), with a ratio male-to-female of 1:2. The patients' age ranged from 5 to 82, the average being 41.5 years at diagnosis. A total of 96 cases (44.4%) occurred in the hand region, followed by 35 cases (16.2%) in the knee, 32 cases (14.8%) in the foot, 25 cases (11.6%) in the ankle, 12 cases (5.6%) in the wrist, 12 cases (5.6%) in the leg, 2 cases (0.9%) in the head, 1 case (0.5%) in the forearm, and 1 case (0.5%) inside and outside the spinal channel. Histopathology mainly revealed large synovial-like monocytes, small monocytes, and osteoclast-like giant cells.

CONCLUSION

Our results confirm that GCTTS predominantly occurs in the hands of young women. Complete surgical resection with long-term follow-up is the preferred management.

Approach to Fine Needle Aspiration of Giant Cell-rich Tumors of Soft Tissue

Giant cells may be found in a wide variety of reactive and neoplastic soft tissue lesions. Because of their distinct histomorphology, they often stand out in procured samples such as fine needle aspirates. The giant cells themselves may be benign or neoplastic. However, the presence, type, and quantity of giant cells are usually not specific and in some cases can even be misleading when making a diagnosis. The aim of this review is to guide the practicing cytopathologist in narrowing their differential diagnosis when encountering one of these challenging giant cell-rich lesions of the soft tissue.

[MULTIPLE GIANT CELL TUMOR OF TENDON SHEATH: A CASE REPORT OF THREE LESIONS ON THE SAME FLEXOR TENDON]

We present a case report of a triple location Giant Cell Tumor of tendon sheath appearance on the same flexor tendon sheath of a single digit. There have been scarce descriptions of multiple Giant Cell Tumors of tendon sheath. Multiple tumors may predispose patients to a higher recurrence rate; therefore, recognition and treatment of this rare entity is important.

Arthroscopic Management of Giant Cell Tumor of the Calcaneus

Giant cell tumor of the calcaneal bone is a very rare entity and generally seen in the 30 to 40 years age group. We report a case of a 17-year-old male with giant cell tumor of the calcaneus, presented with left heel pain without another obvious physical abnormality. Radiographs showed a lobulated, well-defined, lytic lesion of the calcaneus with narrow transitional zone without periosteal reaction, no extraosseal spread, and no lung metastases. Arthroscopic procedure was done directly for both diagnostic and curative procedures. All soft, grayish lesions were completely removed arthroscopically using direct lateral portals and the suspected reactive zones debrided using high-speed burr and injected with corticosteroid. Histopathology confirmed the suspected diagnosis. The postoperative clinical course was uneventful with immediate pain relief and full weight bearing and movement allowed soon. The patient had no recurrent pain as well as recurrent radiographic lesions, and normal joint mobility 9 months postoperatively. Considering the accessibility of the lesion, giant cell tumor of the calcaneal bone can be successfully treated arthroscopically using direct lateral approach.Levels of Evidence: Therapeutic, Level IV: Retrospective, case report.

Efficacy of Pazopanib in the Treatment of Metastatic Malignant Giant Cell Tumor of Soft Tissue: A Case Report

Giant cell tumor of soft tissue (GCT-ST), histologically resembling the GCT of the bone, is a rare tumor. The tumor has been categorized to have low malignancy. Few reports of local recurrence or distant metastasis and the use of chemotherapeutic agents for metastatic GCT-ST exist. Herein, we report the efficacy of pazopanib in a 78-year-old Japanese woman with GCT in the intrinsic back musculature with both post-operative local recurrence and lung metastasis. The patient visited the hospital with a three-month history of a palpable mass in the intrinsic back musculature. Following magnetic resonance imaging, the tumor predominantly exhibited slight hyperintensity on T2-weighted images and intense heterogeneous enhancement on contrast-enhanced T1-weighted images. A percutaneous needle biopsy was performed, and the pathological diagnosis was GCT-ST. The patient underwent surgery, and three months later she presented with not only local recurrence but also multiple lung metastases. The patient was immediately treated with pazopanib 400 mg once daily. One month after initiating treatment, a partial response in the pulmonary lesions was observed, and stable disease (SD) effects lasted for 11 months without severe adverse effects. Therefore, pazopanib treatment for metastatic malignant giant cell tumor of soft tissue achieved reasonable success.

Tenosynovial giant cell tumor

Tenosynovial Giant Cell Tumor (TGCT) is a group of typically benign lesions arising from the synovium of joints, bursae and tendon sheaths. Depending on their growth pattern and clinical course, they are divided into localized and diffuse types. It is predominantly caused by a mutation in the stromal cells of the synovial membrane leading to overexpression of the colony stimulating factor 1 that recruits CSF1R-expressing cells of the mononuclear phagocyte lineage into the tumor mass. The lesions contain mainly histiocyte-like and synovial cells accompanied by varying numbers of multinucleated giant cells, mononuclear cells, foam cells, inflammatory cells and hemosiderin deposits. The gold standard for detect- ing and monitoring the disease is MRI, where the characteristic hemosiderin accumulation can be best appreciated, but it is a histological examination that is most conclusive. The main treatment is surgical resection of all pathological tissue, but radio- and chemotherapy are also viable options for certain groups of patients.

Giant cell tumor arising from the anterior arc of the rib: an extremely rare site in an adolescent girl

BACKGROUND

Giant cell tumor is a rare and locally aggressive neoplasm of the long bones in children. Rib is the least frequently affected site, seen in less than 1% of all cases and most of them occur at the posterior arc.

CASE

A 12-year-old girl presented with swelling and slight pain on the left inferior-anterior chest wall for two years. Physical examination revealed a giant, hard and fixed mass on the left chest wall. Hematological and biochemical test results were in normal limits but slight elevation of alkaline phosphatase level. Computed tomography of the chest showed a large expansive mass and lytic lesion with internal calcification arising from the anterior part of the 7th rib. En-bloc resection was performed including the 6th-8th ribs and a small part of the diaphragm. The pathological evaluation revealed giant cell tumor of bone.

CONCLUSIONS

Herein, we aim to emphasize that giant cell tumor should be considered in the differential diagnosis of chest wall tumors in childhood whereby en-bloc resection and close follow up would be paramount.

Periocular Cutaneous Soft-Tissue Giant Cell Tumor in a Pediatric Patient

ABSTRACT

Giant cell tumor of soft tissue (GCTST) is a rare neoplasm genetically unrelated but histopathologically indistinguishable to its osseous counterpart. Histologically, GCTST is characterized as a multinodular proliferation of bland histiocytoid mononuclear cells intermixed with osteoclast-like giant cells. GCTST most commonly presents as a soft-tissue mass located in the extremities of middle-aged adults. In this report, we describe a case of a dermal GCTST arising in the periocular region of a 3-year-old girl. This is the youngest patient diagnosed with GCTST reported in the literature and is also singular because of its anatomic location: Only a handful of head and neck GCTSTs have been reported to date. Furthermore, GCTST most often presents as a superficial or deep soft-tissue mass and much less commonly as a dermal-based skin tumor, as was our case. On microscopic examination, the resected lesion demonstrated classical features including numerous osteoclast-like giant cells embedded in a background of mononuclear ovoid cells which displayed brisk mitotic activity and were surrounded by variable stromal hemorrhage. Tumor cells presented a vaguely fascicular arrangement. Immunohistochemical profile demonstrated positivity for smooth muscle actin and CD68 and negativity for desmin, myo-D1, S100, HMB-45, Melan-A, p16, and NKIC3. The unusual characteristics of this case emphasize the clinicopathologic heterogeneity of GCTST.

Primary Giant Cell Tumors of the Lung: A Clinicopathologic and Immunohistochemical Study of 3 Cases

Three cases of primary giant cell tumors of the lung akin to those described in the soft tissues are presented. The patients are 3 men between the ages of 43 and 54 years who presented with nonspecific symptoms of cough, chest pain, and shortness of breath. None of the patients had any prior history of malignancy anywhere else. Diagnostic imaging disclosed the presence of an intrapulmonary mass. All the patients underwent lobectomy. Grossly, the tumors were described as solid, slightly hemorrhagic, and measuring between 1.8 and 2.4 cm in greatest diameter. Histologically, the tumors were characterized by a dual population of multinucleated giant cells admixed with a mononuclear proliferation. Nuclear atypia was mild to moderate, and mitotic activity varied but was under 5 mitotic figures per 10 high power fields. Immunohistochemical stains showed positive staining for vimentin, CD68, and cathepsin K, whereas the tumors were negative for keratin, TTF-1, p40, S-100 protein, and SABT-2. Clinical follow-up was obtained in 2 patients who have remained alive and without evidence of recurrence or metastasis up to 12 months after surgery. One patient was lost to follow-up. The current neoplasms represent a tumor that to the best of our knowledge has not been reported as a primary neoplasm of the lung. The cases herein described represent an unusual occurrence and should be maintained in the differential diagnosis of primary pulmonary tumors rich in multinucleated giant cells.

Cytomorphological spectrum of hand, wrist, and foot lesions at tertiary care center in central India

BACKGROUND

Fine-needle aspiration cytology (FNAC) being a fast technique is used as a primary investigation to diagnose wide spectrum of hand, wrist, and foot lesions. These sites are prone to trauma, reparative, and infectious process, which forms mass lesions mimicking neoplasia. Our study highlighted the importance of FNAC with the chance of reduction in biopsy or excision.

AIMS AND OBJECTIVES

To report the prevalence and cytomorphological spectrum of hand and foot lesions with the aim of consolidating the diagnostic potential and also correlate the cytological evaluation with histopathology.

MATERIALS AND METHODS

This retrospective observational study was done in central India for the period of 5.5 years. The archive cytology slides of patients with palpable lesions at these sites are reviewed and analyzed.

RESULTS

Of the total 6512 FNAC cases, 115 cases presented as swelling in the hand, wrist, and foot are reviewed. Age ranged from 4 months to 80 years with M:F = 1.25:1. Of the 111 satisfactory smears (96.7%), 21 cases (18.9%) diagnosed as inflammatory lesion, including synovitis, tuberculosis, gout, and fat necrosis. Sixty cases as benign non-neoplastic (tumor-like) lesions with the most common being ganglion (29). Of the 30 neoplastic lesions, 26 were benign tumor with the most common being mesenchymal neoplasms (19), followed by giant cell tumor of tendon sheath. Malignant tumors included malignant melanoma, small round cell tumor, and squamous-cell carcinoma.

CONCLUSION

FNAC is useful investigation for early diagnosis of hand and foot lesions. These lesions are benign mostly with less malignancy occurrence (<2%), compared with other soft tissue lesions.

Prognostic role of PD-L1 and immune-related gene expression profiles in giant cell tumors of bone

Giant cell tumor of bone (GCTB) is a locally aggressive and rarely metastatic tumor, with a relatively unpredictable clinical course. A retrospective series of 46 GCTB and a control group of 24 aneurysmal bone cysts (ABC) were selected with the aim of investigating the PD-L1 expression levels and immune-related gene expression profile, in correlation with clinicopathological features. PD-L1 and Ki67 were immunohistochemically tested in each case. Furthermore, comprehensive molecular analyses were carried out using NanoString technology and nCounter PanCancer Immune Profiling Panel, and the gene expression results were correlated with clinicopathological characteristics. PD-L1 expression was observed in 13/46 (28.3%) GCTB (and in 1/24, 4.2%, control ABC, only) and associated with a shorter disease free interval according to univariate analysis. Moreover, in PD-L1-positive lesions, three genes (CD27, CD6 and IL10) were significantly upregulated (p < 0.01), while two were downregulated (LCK and TLR8, showing borderline significance, p = 0.06). Interestingly, these genes can be related to maturation and immune tolerance of bone tissue microenvironment, suggesting a more immature/anergic phenotype of giant cell tumors. Our findings suggest that PD-L1 immunoreactivity may help to select GCTB patients with a higher risk of recurrence who could potentially benefit from immune checkpoint blockade.

The reconstruction after en-bloc resection of giant cell tumors at the distal radius: A systematic review and meta-analysis of the ulnar transposition reconstruction technique

BACKGROUND

En-bloc resection of giant cell tumors (GCTs) of the distal radius remains the mainstay treatment for those with high-graded lesions. Several techniques have been described for reconstruction of the resected segment, of which transposition of the ipsilateral ulna is scarcely reported.

OBJECTIVES

To investigate the efficacy and safety of the different techniques of ulnar translocation following GCTs total resection.

METHODS

A systematic review and meta-analysis was conducted concerning the reported functional outcomes, including grip strength, range of forearm motion, functional scores, and new bone formation, as well as postoperative complications, such as delayed union, local recurrence and metastasis. The ranges of functional outcomes were reviewed and the pooled prevalence rates of complication and their respective 95% confidence intervals (95% CIs) were computed.

RESULTS

In a total of 12 studies, 90 patients (51.1% males, 84.8% had Campanacci grade III tumors) underwent five different reconstruction techniques. As compared to the normal side, the mean grip strength in the affected side ranged between 59 and 71%. The average union time was 1-8 months, while delayed union was reported in 50% (95% CI, 15.35 to 84.65) of patients whom their grafts were fixed with Steinmann pins. The shortest union time, the highest forearm supination and pronation degrees, new bone formation at the ulnar stump, and the highest functional scores were reported following a modified distal radius plate technique. Using a dynamic compression plate and a clover leaf plate provided lower, but considerable, functional outcomes.

CONCLUSION

Ulnar translocation following GCT en-bloc resection warrants additional investigation in large cohorts and well-designed studies to corroborate the promising outcomes presented in this review.

Preliminary investigation of bilateral internal iliac artery ligation and anterior tumor separation through laparoscopy before posterior resection of a giant sacral tumor

BACKGROUND

Surgical is the optimal therapeutic strategy for sacral tumors, and complete resection can effectively improve the recurrence and survival rates. However, the specialized anatomy, massive bleeding and adhesion to the anterior tissue, especially that caused by giant sacral tumors, makes complete resection difficult. The laparoscopic technique provides a new method to resect sacral tumors.

METHODS

34 patients with primary giant sacral tumors who underwent surgical resection were enrolled. After bilateral internal iliac artery ligation and anterior laparoscopic tumor separation, the sacral tumors were successfully resected posteriorly. The clinical, radiological and follow-up data were collected and analyzed.

RESULTS

The average operative time was 276.47 min and that for laparoscopy was 76.24 min. The average intraoperative blood loss was 1757.64 ml. No complications associated with laparoscopic surgery, such as intestinal, urinary tract, or vascular injuries, occurred. Ten patients (29.41%) had perioperative complications, including infection, unhealed wounds, and cerebrospinal fluid leaks in 10, 5 and 2 patients, respectively. Patients with complications had significantly longer total (55.00 ± 34.53 vs 25.13 ± 14.60, P = 0.001) and postoperative (39.10 ± 30.61 vs 14.83 ± 10.00, P = 0.002) hospitalization stays than patients without complications. Postoperatively, bowel and bladder dysfunction, intestinal obstruction, pain, and perianal numbness occurred in 21, 5, 8, and 2 patients, respectively. The recurrence rate was 11.76%.

CONCLUSIONS

Laparoscopically assisted sacral tumor resection is a technically feasible and effective surgical method to resect giant sacral tumors, with the advantages of reduced operative blood loss during internal iliac artery ligation and anterior tumor separation.

Processing Techniques for Scanning Electron Microscopy Imaging of Giant Cells from Giant Cell Tumors of Bone

Giant cell tumor (GCT) of bone is a common benign lesion that causes significant morbidity due to the failure of modern medical and surgical treatment. Surface ultra-structures of giant cells (GCs) may help in distinguishing aggressive tumors from indolent GC lesions. This study aimed to standardize scanning electron microscopic (SEM) imaging of GC from GCT of bone. Fresh GCT collected in Dulbecco's Modified Eagle Medium was washed to remove blood, homogenized, or treated with collagenase to isolate the GCs. Mechanically homogenized and collagenase-digested GCs were imaged on SEM after commonly used drying methodologies such as air-drying, tetramethylsilane (TMS)-drying, freeze-drying, and critical point-drying (CPD) for the optimization of sample processing. The collagenase-treated samples yielded a greater number of isolated GC and showed better surface morphology in comparison to mechanical homogenization. Air-drying was associated with marked cell shrinkage, and freeze-dried samples showed severe cell damage. TMS methodology partially preserved the cell contour and surface structures, although the cell shape was distorted. GC images with optimum surface morphology including membrane folding and microvesicular structures on the surface were observed only in collagenase-treated and critical point-dried samples. Collagenase digestion and critical point/TMS-drying should be performed for optimal SEM imaging of individual GCs.

Comparison of outcomes of 2 surgical treatments for proximal humerus giant cell tumors: a multicenter retrospective study

BACKGROUND

The incidence of giant cell tumors in the proximal humerus is low. We evaluated 2 surgical treatments for giant cell tumors of the proximal humerus and postoperative upper-extremity function.

METHODS

This study retrospectively analyzed the clinical data of 27 cases of giant cell tumors of the proximal humerus at 4 Chinese medical centers specializing in bone oncology collected between January 2002 and June 2015. All patients were followed up for more than 2 years. The surgical procedures performed for treatment included curettage in 14 patients and segmental resection in 13. The Campanacci grade, occurrence of pathologic fracture, surgical method, complications, and Musculoskeletal Tumor Society score were recorded for each cohort.

RESULTS

The recurrence rate was 7.1% in the curettage group and 15.4% in the segmental resection group. Other postoperative complications occurred in 4 patients with segmental resection, including resorption of the osteoarticular allograft in 2, subluxation of the glenohumeral joint in 1, and prosthetic loosening and exposure in 1. A significant difference in postoperative upper-extremity function was noted between the 2 groups (P < .001).

CONCLUSIONS

Postoperative upper-extremity function in the curettage group was significantly better than that in the segmental resection group. Segmental resection and reconstruction with a large segmental osteoarticular allograft were considered unadvisable. We suggest that extensive curettage should be selected to treat proximal humerus giant cell tumors as much as possible.

Giant Cell Tumor of Soft Tissue: A Rare Entity

Giant cell tumor (GCT) of the soft tissue (GCT-ST) is a rare, unusual primary soft tissue tumor that is completely distinct from, and should not be confused with, any giant cell-rich tumor of bone or soft tissue. Currently, GCT-ST is included in the group of so-called fibrohistiocytic tumors of intermediate (borderline) malignancy. The most common symptom is a painless, slow-growing mass in a superficial location. Computed tomography and magnetic resonance imaging show a solid, nonhomogeneous, frequently hemorrhagic mass. Differential diagnosis is broad and should include benign and malignant entities. The treatment and excision margins of GCT-ST are controversial. Incomplete surgical excision is usually followed by local recurrence. Biological behavior is unpredictable. Giant cell tumor of the soft tissue has shown a lower mean local recurrence rate compared to GCT of bone but has a higher metastatic and death rate. Therefore, close clinical follow-up is recommended. [Orthopedics. 2019; 42(4):e364-e369.].

An osteoclast-like giant cell tumor embedded in the mural nodule of a pancreatic mucinous cystic neoplasm: A case report and literature review

RATIONALE

Mucinous cystic neoplasms (MCNs) are relatively rare lesions, accounting for 2%-5% of all exocrine pancreatic neoplasms. MCNs mainly occur in women (female:male ratio = 20:1), with a peak incidence in the 5th decade of life. Osteoclast-like giant cell tumors (OGCTs) are rare and relatively aggressive neoplasms, comprising <1% of all pancreatic carcinomas. Herein, we present a rare "combination tumor" case and discuss the impact of mural nodules in pancreatic MCNs considering malignant transformation.

PATIENT CONCERNS

A 54-year-old Mongolian man, without vomiting, nausea or jaundice, presented with abdominal distention since 3 months. He had a 7-year history of diabetes. Physical examinations indicated slight middle abdominal tenderness without rebound tenderness or rigidity. Laboratory results revealed that the level of carcinoembryonic antigen (CEA) was 1.16 ng/ml (normal: <5 ng/ml); CA-199: 30.02 U/ml (normal: <27 U/ml); hemoglobin: 143 g/L; fasting glucose: 7.71 mmol/L; and albumin: 43 g/L. Abdominal enhanced computed tomography revealed a 7 × 6 cm solid neoplasm in the pancreatic body with partial enhancement and heterogeneity. Endoscopic ultrasound revealed a solid-cystic space-occupying lesion in the pancreatic body.

DIAGNOSIS

The preoperative preliminary diagnosis was pancreatic solid-cystic tumor, possibly a solid pseudopapillary tumor. Postoperative pathological findings revealed a pancreatic borderline MCN with an OGCT embedded in a mural nodule of the capsule. Immunohistochemical results indicated a simultaneous dual origin from the epithelium and stroma.

INTERVENTIONS

The patient underwent open distal pancreatectomy and splenectomy. Postoperative blood glucose levels were closely monitored and regulated. We intravenously administered single-agent gemcitabine (1400 mg on day 1) as the first-time chemotherapy, 1 month after surgery. After the first chemotherapy, the patient refused to receive further treatment owing to personal reasons.

OUTCOMES

The patient showed uneventful recovery and was discharged 13 days after the initial surgery. Follow-up was performed 1, 3 and 6 months after surgery. At 6 months, abdominal computed tomography scan showed no signs of recurrence, regional lymphadenopathy, or other abnormalities. And laboratory tests showed a platelet count of 301 × 10/L, postprandial blood glucose of 12.9 mmol/L and CA-199 level of 20 U/ml. The patient had no obvious discomfort.

LESSONS

Although pancreatic MCNs are widely accepted as borderline tumors, malignant transformations may occur due to various risk factors (cyst size, mural nodules, septations, and tumor location). The combination tumor in this case was more likely to increase the possibility of malignant biological behavior, thereby worsening overall prognosis. Therefore, long-term follow-up must be maintained with strict monitoring.

A case of giant cell tumor of the tendon sheath in an elderly patient: diagnostic difficulties and therapeutic options

Giant cell tumor of the tendon sheath (GCTTS) is a benign tumor with a high recurrence rate of up to 50%. The lesion may appear anywhere in the synovium; the nature of this tumor is still controversial, however recent data shows that tenosynovial giant cell tumors (TGCTs) could be clonal neoplastic tumors. Most lesions of GCTTS produce one or more discrete nodules, while the radiological features can include soft-tissue masses with or without bone destruction. In an effort to advance in the understanding of GCTTS pathogenesis, we decided broadly investigate the immunophenotypic profile, of a TGCT in a 69-year-old female patient.

A nonrandomized controlled study of sacral giant cell tumors with preoperative treatment of denosumab

The aim of this nonrandomized controlled study (level 3)was to evaluate whether preoperative denosumab treatment can reduce intraoperative blood loss, facilitate surgical treatment, and improve local control of sacral giant-cell tumor (GCT).Surgical treatment of sacral GCT is very difficult due to extensive bone destruction and complex anatomical structures. The huge intraoperative blood loss may interrupt surgical management and judgment of tumor range. Denosumab can inhibit the differentiation of osteoclast-like giant cells and bone destruction by blocking RANKL-RANK pathway.Study group (preoperative denosumab treatment) and control group (no denosumab treatment) were matched for age, gender, tumor site, staging, and tumor size. In study group, enhanced computed tomography (CT) was performed before and after denosumab treatment. The comparison parameters between 2 groups: CT enhancement rate, intraoperative blood loss, and oncologic outcome.The mean preoperative time of denosumab treatment was 5.2 months in study group. The mean CT enhancement rate of study group was 2.60 before treatment and 1.37 after treatment (P = .012). The posttreatment CT enhancement rate of study group was significantly lower than that of control group (P = .007). The mean intraoperative bleeding of study group and control group was 2166.7 and 5240 mL, respectively (P = .040). The mean operative time of study group and control group was 268.3 and 268.5 minutes, respectively (P = .997). The recurrence rate of study group (66.7%) was significantly higher than that of control group (0%) (P = .046).Preoperative denosumab treatment has the tendency to reduce blood supply and intraoperative bleeding of sacral GCT. But the sclerosis and bony separation can increase the difficulty of tumor curettage and lead to high recurrence rate after denosumab treatment. It is necessary to study the best surgical opportunity after denosumab treatment and precise method to judge tumor range.

Surgical management and long-term outcomes of intracranial giant cell tumors: a single-institution experience with a systematic review

OBJECTIVE

Intracranial giant cell tumors (GCTs) are extremely rare neoplasms with dismal survival and recurrence rates. The authors aimed to confirm independent adverse factors for progression-free survival (PFS) and to propose an optimal treatment algorithm.

METHODS

The authors reviewed the clinical data of 43 cases of intracranial GCTs in their series. They also reviewed 90 cases of previously reported GCTs in the English language between 1982 and 2017 using Ovid MEDLINE, Embase, PubMed, and Cochrane databases with keywords of "giant cell tumor" or "osteoclastoma" and "skull," "skull base," "temporal," "frontal," "sphenoid," or "occipital." These prior publication data were processed and used according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Aforementioned risk factors for the authors' series and the pooled cases were evaluated in patients not lost to follow-up (m = 38 and n = 128, respectively).

RESULTS

The authors' cohort included 28 males and 15 females with a mean age of 30.5 years. Gross-total resection (GTR) was achieved in 15 (34.9%) patients. Fifteen patients (39.5%) who did not undergo GTR received postoperative radiotherapy with a mean total dose of 54.7 ± 4.1 Gy. After a mean follow-up of 71.3 months, 12 (31.6%) patients experienced recurrence, and 4 (10.5%) died of disease. The actuarial 5-year PFS and overall survival (OS) were 68.6% and 90.0% in the authors' cohort, respectively. A multivariate Cox regression analysis verified that partial resection (HR 7.909, 95% CI 2.296-27.247, p = 0.001), no radiotherapy (HR 0.114, 95% CI 0.023-0.568, p = 0.008), and Ki-67 ≥ 10% (HR 7.816, 95% CI 1.584-38.575, p = 0.012) were independent adverse factors for PFS. Among the 90 cases in the literature, GTR was achieved in 49 (54.4%) cases. Radiotherapy was administered to 33 (36.7%) patients with a mean total dose of 47.1 ± 5.6 Gy. After a mean follow-up of 31.5 months, recurrence and death occurred in 17 (18.9%) and 5 (5.6%) cases, respectively. Among the pooled cases, the 5-year PFS and OS were 69.6% and 89.2%, respectively. A multivariate model demonstrated that partial resection (HR 4.792, 95% CI 2.909-7.893, p < 0.001) and no radiotherapy (HR 0.165, 95% CI 0.065-0.423, p < 0.001) were independent adverse factors for poor PFS.

CONCLUSIONS

GTR and radiotherapy were independent favorable factors for PFS of intracranial GCTs. Based on these findings, GTR alone or GTR plus radiotherapy was advocated as an optimal treatment; otherwise, partial resection plus radiotherapy with a dose ≥ 45 Gy, if tolerable, was a secondary alternative. Lack of randomized data of the study was stressed, and future studies with larger cohorts are necessary to verify these findings.Systematic review no.: CRD42018090878 (crd.york.ac.uk/PROSPERO/).

Giant Cell Tumor of Bone: A Model for the in Vitro Human Osteoclast Characterization

The in vitro growth pattern of cells obtained from bioptic material of ten patients with giant cell tumor of bone (GCT) was investigated. Cytochemical reactions and monoclonal antibodies raised against macrophage markers were tested on the two histologically identifiable GCT cell populations. Only monoclonal antibody EBM/11 stained both mononuclear and giant cells. EBM/11 positivity and resistance of acid phosphatase to high doses of tartrate strongly suggest that both mononuclear and giant cells belong to the same lineage.

Giant Cell Tumor of Tendon Sheath: Immunohistochemical Study of 20 Cases

Aims and background

Giant cell tumor of tendon sheath (GCTTS) is a common tumor occurring on the tendon sheaths of the fingers. The nature of this lesion is still controversial: some researchers consider it a reactive process arising from chronic inflammation while others regard it as a tumor of presumed synovial cell or monocytic macrophage system origin. In an effort to clarify the histogenesis we decided to further investigate the immunophenotypic profile of this tumor.

Study design

We studied 20 GCTTS of the fingers using a panel of 18 antibodies, 13 monoclonal and 5 polyclonal.

Results

The immunohistochemical investigation revealed that the mononuclear cells of this lesion can be divided into two groups. The cells of the first and more numerous group were positive for vimentin, PG-M1 and KP1 but also for muscle actin (HHF35 monoclonal antibody) and neuron-specific enolase. A second population of mononuclear cells, usually arranged around the giant cells, were positive for PG-M1, KP1, LCA and occasionally for alpha-1-antitrypsin and alpha-1-antichymotrypsin. Multinucleated giant cells were also positive for KP1, PG-M1 and LCA monoclonal antibodies. A variable but usually weak positivity for al-pha-1-antitrypsin, alpha-1-antichymotrypsin and lysozyme was also observed.

Conclusions

Our results suggest a synovial cell origin for GCTTS and do not support the hypothesis that it could be a neoplasm with a true histiocytic origin. The positivity of some cells for the HHF35 antibody, together with electron microscopic evidence of filament bundles with focal dense bodies, suggests that at least part of the mononuclear cells may have a myofibroblastic differentiation.

Giant Cell Lesion of the Jaw. Case Report

A case is presented of a male patient affected by a giant cell lesion of the jaw, which had two recurrences in 8 years. Histologically, the lesion appeared to be composed of giant cells and mononuclear cells. Histoenzymatic study demonstrated acid phosphatase in both types of cells, and beta-glucuronidase in giant cells only. In some nuclei of giant cells, ultrastructural investigation showed filaments or microtubular structures of variable length, with irregular transverse periodicity, in addition to other expected findings. These characteristic features, found in giant cells of some giant cell tumors of the long bones, have never before been reported in a giant cell lesion of the jaw. The results are considered in order to assess the diagnosis, and the pathologic profiles of giant cell reparative granuloma, and of giant cell tumor are critically discussed.

Giant Cell-Containing Tumors of Bone

Giant cell-containing tumors of bone are characterized morphologically by the presence of numerous osteoclastic giant cells. Correlation of clinical, radiologic, and laboratory findings is required for accurate histopathologic diagnosis and treatment of a giant cell-containing tumor of bone. In differential diagnosis, it is particularly important to note the age of the patient and the skeletal location of the lesion. This article considers the range of neoplastic and nonneoplastic lesions, which histologically contain numerous osteoclastic giant cells, and focuses on several lesions that frequently enter into the differential diagnosis.

Customized Knee Prosthesis in Treatment of Giant Cell Tumors of the Proximal Tibia: Application of 3-Dimensional Printing Technology in Surgical Design

BACKGROUND We explored the application of 3-dimensional (3D) printing technology in treating giant cell tumors (GCT) of the proximal tibia. A tibia block was designed and produced through 3D printing technology. We expected that this 3D-printed block would fill the bone defect after en-bloc resection. Importantly, the block, combined with a standard knee joint prosthesis, provided attachments for collateral ligaments of the knee, which can maintain knee stability. MATERIAL AND METHODS A computed tomography (CT) scan was taken of both knee joints in 4 patients with GCT of the proximal tibia. We developed a novel technique - the real-size 3D-printed proximal tibia model - to design preoperative treatment plans. Hence, with the application of 3D printing technology, a customized proximal tibia block could be designed for each patient individually, which fixed the bone defect, combined with standard knee prosthesis. RESULTS In all 4 cases, the 3D-printed block fitted the bone defect precisely. The motion range of the affected knee was 90 degrees on average, and the soft tissue balance and stability of the knee were good. After an average 7-month follow-up, the MSTS score was 19 on average. No sign of prosthesis fracture, loosening, or other relevant complications were detected. CONCLUSIONS This technique can be used to treat GCT of the proximal tibia when it is hard to achieve soft tissue balance after tumor resection. 3D printing technology simplified the design and manufacturing progress of custom-made orthopedic medical instruments. This new surgical technique could be much more widely applied because of 3D printing technology.

Giant Cell Tumors of the Bone With Pulmonary Metastasis

Giant cell tumors of the bone are benign but locally aggressive, and they rarely metastasize to the lungs. The purpose of this study was to retrospectively review the clinical presentation, long-term outcomes, and treatment of pulmonary metastasis of these tumors. Between 1991 and 2004, a total of 168 patients with giant cell tumors of the bone were treated at the authors' institution, 7 of whom developed lung metastasis. Four of the 7 patients were men, and mean age of these patients at initial surgery was 40 years (range, 19-56 years). All patients underwent wide excision and reconstruction or curettage and bone grafting for the bony lesions. Lung metastases were detected at a mean of 44 months after the treatment of bone lesions. Five patients had multiple metastases, and 2 had solitary pulmonary metastases. Six of these patients underwent delayed treatment, locally aggressive, or multiple recurrent and surgical procedures. All of the aforementioned procedures had similar risk factors to those previously reported in the literature. One patient had multiple giant cell tumors of the bone. At last follow-up, 2 patients had died due to complications from the pulmonary metastases or chemotherapy. One patient underwent a metastasectomy 4 years after treatment due to the progression of pulmonary metastasis. The remaining 4 patients were alive and healthy after chemotherapy or conservative treatment. Therefore, early detection, adequate treatment of the primary bone lesion, conservative treatment of lung metastases, and regular long-term follow-up are recommended.

Histochemical analysis of collagen fibers in giant cell fibroma and inflammatory fibrous hyperplasia

OBJECTIVE

The aim was to investigate collagen fibers in giant cell fibroma, inflammatory fibrous hyperplasia, and oral normal mucosa.

MATERIALS AND METHODS

Sixty-six cases were stained with picrosirius red. The slides were observed under polarization, followed by the measurement of the area and the percentage of the type I and type III collagens. The age and gender were obtained from the clinical records.

RESULTS

No differences could be observed in both the area and percentage of the type I and type III collagens within the categories of lesions and normal mucosa. In the giant cells fibroma, a greater area and percentage of type I collagen could be identified in individuals of less than 41.5 years (p<0.05).

CONCLUSION

The distribution of type I and type III collagen fibers in the studied lesions followed a similar pattern to that observed in the normal mucosa, indicating a normal collagen maturation process of type III to I. The study supports that multinucleated and stellate cells of the giant cell fibroma appear to be functional within collagen types III and I turnover. The greater amount of type I collagen identified in giant cell fibroma in individuals of less than 41.5 years reinforce the neoplastic nature of lesion.

Ultrasonography role in the evaluation of a giant cell tumor of the flexor pollicis longus tendon

Hand tendons lesions represent a challenge for an accurate diagnosis, an optimal treatment strategy, the description of the lesion and its location being an important step. The non-invasive ultrasound evaluation was demonstrated to be an important diagnostic method in these types of lesions, especially in those situations where clinical evaluation failed to reveal the pathological changes and therefore has an important role in the adequate management.

Tenosynovial giant cell tumour (pigmented villonodular synovitis-)-like changes in periprosthetic interface membranes

Tenosynovial giant cell tumour (TSGCT; synonym, pigmented villonodular synovitis (PVNS)) is a rare low-grade mesenchymal neoplasm of either intra-articular or extra-articular origin. The etiopathogenesis of TSGCT is still uncertain, but recent studies showed a translocation involving colony-stimulating factor 1 (CSF-1) gene in a subset of cases. Histological features mimicking TSGCT can sometimes be encountered in periprosthetic interface membranes. To investigate the frequency and morphologic spectrum of this phenomenon, we conducted a systematic analysis of 477 periprosthetic interface membranes and performed immunohistochemical analysis on a subset of lesions compared to genuine TSGCT. In 26 of 477 periprosthetic membrane samples (5 %), at least some TSGCT-like features were found and 18 cases (4 %) strongly resembled it. Wear particles were detected in 100 % of the TSGCT-like lesions but only in 63.3 % of the whole cohort of periprosthetic membranes (p value <0.001). Immunohistochemistry comparing true TSGCT and TSGCT-like membranes showed similar inflammatory infiltrates with slightly elevated CD3+/CD8+ T lymphocytes and a slightly higher proliferation index in TSGCT samples. In conclusion, TSGCT-like changes in periprosthetic membranes likely represent exuberant fibrohistiocytic inflammatory response induced by wear particles and should be distinguished from genuine (neoplastic) TSGCT. Although TSGCT and TSGCT-like periprosthetic membranes represent different entities, their comparable morphology might reflect analogous morphogenesis.

Undifferentiated carcinoma of the pancreas with osteoclast-like giant cells: a rare case report and review of the literature

Undifferentiated carcinoma of the pancreas with osteoclast-like giant cells (UCPOGC) is an extremely rare non-endocrine pancreatic tumor. To date, some cases have been reported, however, histogenesis and biologic behavior of UCPOGC remain controversial. We report a case of an UCPOGC in a 54-year-old female, who presented with a three-month history of recurrent abdominal pain without any incentive. Abdominal computed tomography (CT) revealed a large cystic mass of 10.5 × 9.3 cm in the body and tail of the pancreas compressing the adjacent bowel loop and stomach. The preliminary diagnosis was considered as a malignant tumor of body and tail of the pancreas. The patient had open distal pancreatic mass resection with splenectomy and according to the results of histopathological and immunohistochemical studies, the diagnosis of an UCPOGC was established.

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.

Structure-Guided Blockade of CSF1R Kinase in Tenosynovial Giant-Cell Tumor

BACKGROUND

Expression of the colony-stimulating factor 1 (CSF1) gene is elevated in most tenosynovial giant-cell tumors. This observation has led to the discovery and clinical development of therapy targeting the CSF1 receptor (CSF1R).

METHODS

Using x-ray co-crystallography to guide our drug-discovery research, we generated a potent, selective CSF1R inhibitor, PLX3397, that traps the kinase in the autoinhibited conformation. We then conducted a multicenter, phase 1 trial in two parts to analyze this compound. In the first part, we evaluated escalations in the dose of PLX3397 that was administered orally in patients with solid tumors (dose-escalation study). In the second part, we evaluated PLX3397 at the chosen phase 2 dose in an extension cohort of patients with tenosynovial giant-cell tumors (extension study). Pharmacokinetic and tumor responses in the enrolled patients were assessed, and CSF1 in situ hybridization was performed to confirm the mechanism of action of PLX3397 and that the pattern of CSF1 expression was consistent with the pathological features of tenosynovial giant-cell tumor.

RESULTS

A total of 41 patients were enrolled in the dose-escalation study, and an additional 23 patients were enrolled in the extension study. The chosen phase 2 dose of PLX3397 was 1000 mg per day. In the extension study, 12 patients with tenosynovial giant-cell tumors had a partial response and 7 patients had stable disease. Responses usually occurred within the first 4 months of treatment, and the median duration of response exceeded 8 months. The most common adverse events included fatigue, change in hair color, nausea, dysgeusia, and periorbital edema; adverse events rarely led to discontinuation of treatment.

CONCLUSIONS

Treatment of tenosynovial giant-cell tumors with PLX3397 resulted in a prolonged regression in tumor volume in most patients. (Funded by Plexxikon; ClinicalTrials.gov number, NCT01004861.).