Fine-needle aspiration cytologic diagnosis of giant-cell tumor of the sacrum presenting as a rectal mass: A case report

State of the Art and New Concepts in Giant Cell Tumor of Bone: Imaging Features and Tumor Characteristics

Simple Summary

The 2020 World Health Organization classification of soft tissue and bone tumors classified the giant cell tumor of bone (GCTB) as an intermediate malignant tumor, with locally aggressive behavior and high recurrence rate. Imaging plays a pivotal role in the assessment of GCTB, and this review tries to summarize the main concepts about GCTB histopathogenesis and new biomarkers, describing those GCTB imaging findings which could possibly be explained by tumor molecular alterations. We have illustrated pre-operative imaging features related to prognosis and radiological findings for response evaluation after surgical treatment and denosumab administration. We have also reported the results described in literature regarding the role of radiomics in aiding GCTB diagnosis, predicting possible post-treatment recurrence and providing a quantitative assessment of the response to denosumab treatment.

Abstract

Giant cell tumor of bone (GCTB) is classified as an intermediate malignant tumor due to its locally aggressive behavior, burdened by high local recurrence rate. GCTB accounts for about 4–5% of all primary bone tumors and typically arises in the metaphysis and epiphyses of the long tubular bones. Mutation of gene H3F3A is at the basis of GCTB etiopathogenesis, and its immunohistochemical expression is a valuable method for practical diagnosis, even if new biomarkers have been identified for early diagnosis and for potential tumor recurrence prediction. In the era of computer-aided diagnosis, imaging plays a key role in the assessment of GCTB for surgical planning, patients’ prognosis prediction and post treatment evaluation. Cystic changes, penetrating irregular margins and adjacent soft tissue invasion on preoperative Magnetic Resonance Imaging (MRI) have been associated with a higher rate of local recurrence. Distance from the tumor edge to the articular surface and thickness of unaffected cortical bone around the tumor should be evaluated on Computed Tomography (CT) as related to local recurrence. Main features associated with local recurrence after curettage are bone resorption around the graft or cement, soft tissue mass formation and expansile destruction of bone. A denosumab positive response is represented by a peripherical well-defined osteosclerosis around the lesion and intralesional ossification. Radiomics has proved to offer a valuable contribution in aiding GCTB pre-operative diagnosis through clinical-radiomics models based on CT scans and multiparametric MR imaging, possibly guiding the choice of a patient-tailored treatment. Moreover, radiomics models based on texture analysis demonstrated to be a promising alternative solution for the assessment of GCTB response to denosumab both on conventional radiography and CT since the quantitative variation of some radiomics features after therapy has been correlated with tumor response, suggesting they might facilitate disease monitoring during post-denosumab surveillance.

Modified kraske procedure with mid-sacrectomy and coccygectomy for en bloc excision of sacral giant cell tumors

Sacral giant cell tumors are rare neoplasms, histologically benign but potentially very aggressive due to the difficulty in achieving a complete resection, their high recurrence rate, and metastization capability. Although many treatment options have been proposed, en bloc excision with tumor-free margins seems to be the most effective, being associated with long term tumor control, improved outcome, and potential cure. An exemplifying case of a 29-year-old female with progressive complaints of pain and paresthesias in the sacral and perianal regions, constipation, and weight loss for 6 months is presented. The surgical technique for en bloc excision of a large sacral giant cell tumor through a modified Kraske procedure with mid-sacrectomy and coccygectomy is described. Complete resection with wide tumor-free margins was achieved. At 5 years of follow-up the patient is neurologically intact, without evidence of local recurrence on imaging studies. A multidisciplinary surgical procedure is mandatory to completely remove sacral tumors. In the particular case of giant cell tumors, it allows minimizing local recurrence preserving neurovascular function, through a single dorsal and definitive approach.

Overexpression of hypoxia-inducible factor-1α and vascular endothelial growth factor in sacral giant cell tumors and the correlation with tumor microvessel density

Although classified as benign, giant cell tumors of the bone (GCTB) may be aggressive, recur and even metastasize to the lungs. In addition, the pathogenesis and histogenesis remain unclear; thus, the driving factors behind the strong tumor growth capacity of GCTB require investigation. In the present study, the expression levels of hypoxia-inducible factor (HIF)-1α and vascular endothelial growth factor (VEGF), which are promoted by hypoxic conditions, were determined in 22 sacral GCTB samples using immunohistochemistry and western blot analysis. Furthermore, CD34 expression was analyzed using these methods. The correlation between HIF-1α or VEGF expression and the tumor microvessel density (MVD) was then determined. The results demonstrated that HIF-1α, VEGF and CD34 were overexpressed in the 22 sacral GCTB specimens, and overexpression of HIF-1α and VEGF correlated with the tumor MVD. Thus, the present study has provided novel indicators for the tumor growth capacity of GCTBs.

Current treatment of sacral giant cell tumour of bone: a review

Sacral giant cell tumour of bone has an insidious onset and slow growth rate, making early diagnosis difficult. The tumour has a high recurrence rate and is often fatal. Magnetic resonance imaging and computed tomography (CT), including CT-guided fine-needle biopsy, are useful for early diagnosis. Although therapy for sacral giant cell tumour often involves surgical resection and reconstruction challenges, improvements in various treatment modalities, including arterial embolization and radiotherapy, have widened the effective treatment options. The current surgical and adjuvant treatment modalities available for the management of sacral giant cell tumour are systematically reviewed and a suggested treatment algorithm is provided. En bloc excision remains the surgical procedure of choice, with functional reconstruction important in cases where the lesion is high in the sacrum. The use of adjuvant radiotherapy and chemotherapy remains controversial and should be studied further. Determination of the optimum treatment for sacral giant cell tumour will require randomized controlled trials. Early diagnosis, complete surgical resection with tumour-free margins and comprehensive treatment are important for local tumour control and improved outcome.

Giant cell tumor of the sacrum

Giant cell tumor (GCT) is a locally highly aggressive tumor of bone comprising 5 to 10% of all benign bone tumors. The sacrum is the third most common site of involvement. Patients with sacral GCTs present with localized pain in the lower back that may radiate to one or both lower limbs. Vague abdominal complaints and bowel and bladder symptoms may also be present. Neuroimaging workup should include advanced modalities, preferably magnetic resonance imaging, prior to obtaining a biopsy specimen. Giant cell tumor has a 1 to 5% rate of metastasizing to the lung and may convert to a fulminate malignant variant, which has a very poor prognosis. The standard treatment for GCT is curettage combined with adjuvant bone grafting or cement-augmented stabilization. In appropriately selected cases, sacral resection is a valuable procedure to effect local tumor control and overall survival. Embolization may also prove palliative and/or curative in cases in which the tumor is unresectable or refractory to treatment.

Diagnostic value of open and needle biopsies in tumors of the sacrum

STUDY DESIGN

A retrospective study with statistical analysis of 25 percutaneous needle biopsies and 54 open biopsies performed on 60 patients with tumors located in the sacrococcygeal region.

OBJECTIVES

To analyze the diagnostic value of open and needle biopsies in tumors of the sacrum as well as to determine factors leading to a false or equivocal result.

SUMMARY OF BACKGROUND DATA

Although percutaneous needle biopsies of the spine are valuable for thoracolumbar levels, the benefit in the sacrococcygeal region, specifically, has not previously been shown. This region is unique because of anatomic and oncologic factors.

METHODS

Medical charts, imaging studies, and operative and pathologic records of patients with tumors diagnosed between 1965 and 1996 in the sacrococcygeal region reviewed were analyzed. Accuracy and effective accuracy of each procedure were then calculated.

RESULTS

There were 54 primary lesions (17 benign, 37 malignant) and 6 metastatic tumors. The accuracy and effective accuracy of open biopsies was 87% and 81% but in percutaneous needle biopsies was only 44% and 12%, respectively. An unclear diagnosis resulted in the need for another biopsy in 12 of 21 primary percutaneous needle biopsies but only in 2 of 39 open biopsies (P < 0.0001, chi2). The average number of biopsies required to obtain a definitive diagnosis was significantly less if an open biopsy were performed first instead of a percutaneous needle biopsy, 1.1 versus 1.8, respectively (P = 0.0004, two-sample t test). There was a significant delay in treatment if the initial biopsy was a percutaneous needle biopsy compared with an open biopsy, mean 46 versus 4 days, respectively (P = 0.004, two-sample t test).

CONCLUSION

We conclude that for sacral tumors, open biopsies have a higher effective accuracy, whereas needle biopsies are associated with a longer delay in treatment.

Massive intestinal hemorrhage resulting from a polypoid tumor in the sigmoid colon: an unusual complication of a giant cell tumor of the fifth lumbar vertebra

STUDY DESIGN

Clinicopathologic study of a case of giant cell tumor of the spine.

SUMMARY OF BACKGROUND DATA

Giant cell tumors of the spine are uncommon, accounting for 1.3-6.5% of all cases in various series. Because of their location, they may cause neurologic deficits. The treatment consists of excision or curettage and has been claimed to give good results.

METHODS

A 33-year-old woman presented with low back pain in 1995; radiologic investigation and biopsy showed features of giant cell tumor involving the fifth lumbar and first sacral vertebrae. Wide excision was performed, but the tumor recurred in 1996 and was curetted. She developed massive intestinal bleeding in 1997 resulting from infiltration of the sigmoid colon by giant cell tumor in the form of a polypoid intraluminal mass. The involved segment of colon was resected, and the patient remained alive, although debilitated, 7 years after initial presentation.

RESULTS

Examination of the tumor in the spine and the colon showed typical histology of giant cell tumor with no evidence of malignant transformation. The involved colon was freely mobile and away from the tumor of the spine.

CONCLUSION

Giant cell tumor of the spine can result in unusual complication, massive intestinal hemorrhage in our case, which causes considerable morbidity.

Fine-needle aspiration diagnosis of giant cell tumour of bone presenting at unusual sites

Giant cell tumour (GCT) of bone is a distinctive neoplasm, which has only recently been included within the diagnostic purview of the cytopathologist. Four cases of GCT of bone diagnosed primarily and exclusively by fine needle aspiration cytology (FNAC), presenting at unusual sites, are presented with a view to highlight the cytomorphologic features of this tumour and its differential diagnosis on FNAC. Each of these cases were distinctive by virtue of their localisation, but presented as classical expansile osteolytic lesions roentgenologically. Despite the paucity of literature regarding the cytodiagnosis of these lesions, the authors nevertheless recommend FNAC as a primary tool in the diagnosis of these lesions.