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

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.

Medical Therapy of Giant Cell Tumor of Bone

Giant cell tumor of bone (GCTB) is mostly a benign disease of the bone, although with high local recurrence rate and potential for metastatic spread, namely to the lungs. It is also a locally aggressive tumor, associated with severe morbidity and functional impairment due to bone destruction. Treatment is therefore required and should be offered at an early stage to allow complete resection, minimizing functional sequelae and local recurrence. Surgical resection is the mainstay of treatment, often followed by intralesional adjuvant therapy. GCTB has a particular biology, in which RANKL represents a key factor in tumor pathogenesis, thus making this molecule a valuable therapeutic target. Monthly administration of denosumab, a fully human monoclonal antibody directed against RANKL, has been studied in several clinical trials and shown a high rate of local control with favorable safety profile. In this chapter, current medical management, ongoing studies, and future directions in GCTB will be discussed.

Pilomatrixoma with Atypical Features: A Case Report

Pilomatrixoma is an uncommon, benign tumor with differentiation towards both the hair matrix and cells arising in the cortex, most frequently appearing in the first or second decade of life. In rare instances, pilomatrixomas can show malignant transformation. Pilomatrix carcinoma is extremely uncommon and has traditionally been considered a tumor of low malignant potential; however, a high local recurrence rate has been reported. There is a paucity of literature on these lesions, with only a few reports describing the spectrum of malignant changes seen in these lesions. In this case report, we present a case of pilomatrixoma in an adult patient showing atypical features. While the tumor is small, there are focal features that suggest progression to malignancy, but do not fulfill the criteria for pilomatrix carcinoma. These focal atypical features include a focal infiltrative pattern at the periphery, with a variable cytological atypia and an increased mitotic rate, up to five mitotic events/high-power field. Irregular foci of central necrosis (comedonecrosis) were present in several lobules. Some of the features identified were similar to a subset of pilomatrixoma, known as “proliferating pilomatrixoma.” However, our case did not have the diffuse changes or larger size that has been frequently reported in “proliferating pilomatrixoma.” In conclusion, given the lack of focality of the changes, the lesion in our case is best described as a pilomatricoma with atypical features. Furthermore, our case may highlight the need to ensure close clinical follow-up for these lesions with unexpected atypical features that raise concern of recurrence and malignant transformation.

CYTO HISTOLOGIC CORRELATION OF A LOW GRADE FIBROMYXOID SARCOMAAT AN UNUSUAL LOCATION – A CASE REPORT

BACKGROUND Low grade fibromyxoid sarcoma (LGFMS) is a rare tumour of the deep soft tissues seen in young adults. The histologic features of LGFMS are well established, however the cytologic findings are scantily defined and the distinction from other benign and malignant myxoid soft tissue tumours is difficult. CASE DETAILS A 29 year old male presented with a superficial swelling in the left areolar region for two months. USG revealed a well-defined 2 by 2 cm hyperechoic lesion extending upto the subcutaneous fat. FNA yielded mucoid material and smears showed spindle cells having round to elongated nuclei with mild anisokaryosis, bland chromatin and wispy cytoplasm in a myxoid background. No significant nuclear pleomorphism or mitoses were noted. A diagnosis of myxoid mesenchymal lesion was made. The excised tumour was well circumscribed with grey white cut surface showing myxoid areas. Microscopically, the tumour displayed moderate cellularity with storiform, intersecting and parallel bundles of spindle cells showing mild nuclear pleomorphism. The myxoid areas showed cells in a haphazard fashion floating in abundant mucoid matrix associated with a capillary network. The mitotic index was low. IHC showed tumor cells positive for vimentin and negative for S-100 & SMA. CONCLUSION LGFMS is a rare low-grade malignancy with a high local recurrence rate and late metastasis. The diagnosis of LGFMS can be difficult to render from fine needle aspiration cytology (FNAC) alone because of morphological overlap with other spindle cell and myxoid lesions. Cytohistological correlation and IHC is helpful in arriving at a correct diagnosis.

Paediatric desmoid tumour of the head and neck: a complete response to chemotherapy and the paradigm shift towards non-surgical management

Desmoid tumours are rare locally aggressive mesenchymal tumours with a high local recurrence rate, particularly in the head and neck locations. We present the case of a 5-year-old child with a locally invasive inoperable desmoid tumour of the masticator space who underwent a low-dose chemotherapy regimen for 17 months, obtaining a long-term complete response. Definitive evidenced-based treatment guidelines are lacking. Therefore, paediatric patients should be managed by specialised multidisciplinary teams to try to achieve the best tumour control while minimising treatment associated morbidity and mortality. Available treatment options include surgery, radiotherapy and different systemic medical therapies. Whereas traditionally, surgery was the mainstay of treatment, more conservative options have increasingly shown adequate tumour control with little associated morbidity. In this decision making it is mandatory to take into account the patient’s age, tumour location and extension, and potential short-term and long-term treatment-related sequelae to minimise functional and cosmetic compromise.

Cutaneous Angiosarcoma - A Clinicopathological Study of 16 Cases over a Period of Nine Years

BACKGROUND Cutaneous angiosarcoma is an aggressive malignant mesenchymal vasoformative neoplasm accounting for 1 % of all soft tissue sarcomas. It carries a poor prognosis with high local recurrence rate. Cutaneous angiosarcoma occurs in 3 clinical settings namely idiopathic angiosarcoma of head and neck, angiosarcoma associated with chronic lymphedema and post irradiation angiosarcoma. Idiopathic angiosarcoma of head and neck of elderly are distinct from other types of angiosarcoma. Clinicopathological correlation of cutaneous angiosarcomas diagnosed during a period of nine years from January 2010 to July 2019 was done. METHODS We retrospectively studied and analysed specific data such as age, sex, site, size, clinical setting as well as six histopathological parameters and follow up. RESULTS There were 30 patients diagnosed as angiosarcoma. 16 of these cases were cutaneous. Their mean age was 60 years (44 – 80 years). Mean size of cutaneous tumours was 4 cms (3 – 10 cm). 15 were primary; one had history of preceding lymphedema. Most common location was scalp (14) followed by leg (2). Predominant pattern was vasoformative (75 %) which included spindle (62.5 %) and epithelioid (37.5 %) cell types. Four (25 %) showed extensive necrosis; ten (66.6 %) had high mitotic index and 12 (75 %) showed tumour infiltrating lymphocytes. All cases (100 %) were positive for CD31 & CD34. All underwent wide local excision. Adjuvant chemotherapy was given in two cases and adjuvant radiotherapy in three cases. Of the seven cases with follow up, five cases died of their disease and two survived. CONCLUSIONS Larger tumour size & older age group were associated with worse outcome. All our 14 cases very well fit with the angiosarcoma of scalp & face in elderly persons as described in the literature. This disease has unique characteristics compared to angiosarcoma in other locations. KEYWORDS Cutaneous, Angiosarcoma, Scalp, Elderly

Clear cell chondrosarcoma of proximal femur: a rare entity with diagnostic dilemma

Clear cell chondrosarcoma is an extremely rare malignant neoplasm. The rarity and slow-growing nature of this tumour often lead to prolonged symptoms and also initial misdiagnosis with benign lesions such as chondroblastoma. It can also be confused with avascular necrosis of the femoral head when the lesion is located in the femoral head, as was in the case we report. The patient was kept on observation and conservative treatment for almost 9 years before the correct diagnosis and appropriate treatment. Wide local resection with negative margins forms the mainstay of treatment since intralesional procedures predispose to high local recurrence rate. A prolonged follow-up is recommended since late local recurrences and metastases are common.

Cryoablation of Extra-Abdominal Desmoid Tumors: A Single-Center Experience with Literature Review

Cryoablation (CA) has gained popularity in the treatment of benign and malignant musculoskeletal tumors. While extra-abdominal desmoid (EAD) tumors are not malignant, they remain challenging to treat because of their high local recurrence rate. We reviewed all EAD tumors treated with CA at our institution between November 2012 and March 2020. Fourteen procedures were performed on nine females and one male (mean age, 33 ± 18 years) as either first-line (n = 4) or salvage therapy (n = 6) with curative intent (n = 8) or tumor debulking (n = 2). Mean tumor size was 63.6 cm3 (range, 3.4–169 cm3). Contrast-enhanced MRI was performed before treatment and at 3-, 6-, and 12-month follow-up. Treatment outcome was based on the change in enhanced tumor volume (ET-V). For curatively treated patients, the mean ET-V change was −97 ± 7%, −44 ± 143%, and +103 ± 312% at 3, 6, and 12 months, respectively. For debulking patients, the mean ET-V change was −98 ± 4%, +149 ± 364%, and +192 ± 353% at 3, 6, and 12 months, respectively. During a mean follow-up of 53.7 months (range, 12–83 months), one grade III and one grade IV complication were noted. We found CA to be safe and well tolerated in patients with EAD.