Ultra-rare sarcomas: a consensus paper from the Connective Tissue Oncology Society community of experts on the incidence threshold and the list of entities

Background Among sarcomas, which are rare cancers, many types are exceedingly rare; however, a definition of ultra-rare cancers has not been established. The problem of ultra-rare sarcomas is particularly relevant because they represent unique diseases, and their rarity poses major challenges for diagnosis, understanding disease biology, generating clinical evidence to support new drug development, and achieving formal authorization for novel therapies.Methods The Connective Tissue Oncology Society promoted a consensus effort in November 2019 to establish how to define ultra-rare sarcomas through expert consensus and epidemiologic data and to work out a comprehensive list of these diseases. The list of ultra-rare sarcomas was based on the 2020 World Health Organization classification, The incidence rates were estimated using the Information Network on Rare Cancers (RARECARENet) database and NETSARC (the French Sarcoma Network's clinical-pathologic registry). Incidence rates were further validated in collaboration with the Asian cancer registries of Japan, Korea, and Taiwan.Results It was agreed that the best criterion for a definition of ultra-rare sarcomas would be incidence. Ultra-rare sarcomas were defined as those with an incidence of approximately <= 1 per 1,000,000, to include those entities whose rarity renders them extremely difficult to conduct well powered, prospective clinical studies. On the basis of this threshold, a list of ultra-rare sarcomas was defined, which comprised 56 soft tissue sarcoma types and 21 bone sarcoma types.conclusions Altogether, the incidence of ultra-rare sarcomas accounts for roughly 20% of all soft tissue and bone sarcomas. This confirms that the challenges inherent in ultra-rare sarcomas affect large numbers of patients.Experimentele farmacotherapi

Digital Fibromyxoma (Superficial Acral Fibromyxoma): A Detailed Characterization of 124 Cases

Molecular tumour pathology - and tumour genetic

Diffuse-type giant cell tumor: Clinicopathologic and immunohistochemical analysis of 50 cases with extraarticular disease

The clinical and pathologic features of 50 cases of diffuse-type tenosynovial giant cell tumor (D-TGCT), also known as extraarticular pigmented villonodular tenosynovitis (PVNTS), are presented. Patients' ages ranged from 4 to 76 years (median, 41 yrs), with a slight female predominance (28 women, 22 men). By definition, all lesions presented as predominant soft tissue masses, with or without an associated articular component. Tumor sites included the wrist (9 cases), knee (8 cases), thigh and foot (6 cases each), finger (5 cases), ankle (3 cases), hand, elbow, toes, buttock, paravertebral region (2 cases each), lower leg, sacrococcygeal area, and retroperitoneum; 27 cases were described as entirely extraarticular. Tumors showed infiltrative margins and, in most cases, a sheet-like growth pattern. Striking variation in the number of osteoclast-like giant cells, foamy cells, amount of hemosiderin, and in the degree of stromal hyalinization were responsible for a wide morphologic spectrum. In addition to the predominant histiocyte-like cells, we identified in most cases a subpopulation of large dendritic, desmin-positive cells showing characteristic, but potentially misleading, cytologic features, including abundant eosinophilic cytoplasm, large vesicular nuclei, paranuclear eosinophilic inclusions, and occasional nuclear inclusions. Follow-up information was available for 24 patients, with a duration ranging from 6 months to 30 years (mean, 55 mos). Local recurrence occurred in eight cases (33%), between 4 months and 6 months after surgery (median, 15 mos) and was repeated in five cases; recurrence did not appear to correlate with morphologic parameters. Six cases showed atypical histologic features and four of these contained areas of sarcomatous change. Among the latter, one of three cases with available follow up developed pulmonary metastases and died after 35 months. In addition, one histologically benign lesion gave rise, after two local recurrences, to inguinal and iliac lymph node metastases. Despite this exceedingly uncommon event, we think most cases of D-TGCT are best regarded as benign but locally aggressive neoplasms with significant recurrent potential and should be treated, when possible, by wide excision. Atypical features such as increased mitotic activity, necrosis, spindling of the mononucleate cells, and cytologic atypia are not indicative of malignancy when present individually. This study also confirms the existence of malignant tenosynovial giant cell tumors, some of which are characterized by aggressive behavior.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Leiomyosarcoma of soft tissue in children: Clinicopathologic analysis of 20 cases

Leiomyosarcoma in the pediatric age group is uncommon and incompletely characterized. A series of 20 primary leiomyosarcomas of soft tissue occurring in children younger than 16 years is presented. No significant gender predilection was observed (11 girls and 9 boys). Patient age ranged from 4 to 15 years (median, 12 years). Tumor size ranged from 0.5 to 13 cm (median, 2.5 cm); subcutaneous and deep locations were equally represented. Tumors were evenly distributed among the trunk (30%), head and neck (25%), lower limbs (25%), and upper limbs (20%). All lesions showed at least focally typical features of smooth muscle differentiation, principally in the form of fascicles of eosinophilic spindle cells with cigar-shaped nuclei. An unusual whorled growth pattern was seen in two cases. Morphologic variants including inflammatory leiomyosarcoma (one case), granular cell leiomyosarcoma (two cases), giant-cell rich leiomyosarcoma (two cases), and epithelioid leiomyosarcoma (one case) were seen. Dystrophic calcifications were present in two cases. Most lesions (85%) were low grade. Immunohistochemical staining showed positivity for α-smooth muscle actin in 89% of the cases, HHF-35 in 87%, and desmin in 61%. Positivity for cytokeratins, observed in 6 (43%) of 14 cases tested, was usually strong and was diffuse in two cases. Follow-up data, available in 15 (75%) patients (median duration, 49 months), showed late local recurrence in only two cases, one with progression to a higher grade lesion, and no metastasis. These results show that, although extremely rare, soft-tissue leiomyosarcomas do occur in children, in whom they usually present as small morphologically low-grade lesions that seem to behave in a relatively indolent fashion, although longer follow-up data are needed. Differential diagnosis in this setting includes infantile myofibromatosis, leiomyoma, monophasic synovial sarcoma, and spindle cell rhabdomyosarcoma.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Soft-tissue sarcomas: An update

Despite their relative infrequency (which is often used as an excuse for poor treatment), soft-tissue sarcomas have been the focus of considerable interest and advances in recent years, mainly because of molecular genetic developments as well as evolution in their histological classification. In parallel, however, there remains no clear consensus regarding either the ideal biopsy technique (in this era of increasing outpatient management) or the best means of prognostication (particularly by histological grading). This review aims to discuss some of these recent developments and co-existent controversies. Aside from the understandable pursuit of modern biotechnological innovations, it seems that the most important goal remains the need to achieve more consistent primary surgical management of these tumours, preferably in specialist centres.SCOPUS: re.jinfo:eu-repo/semantics/publishe

Gastrointestinal stromal tumours: An update

Purpose. To study the evolution of concepts concerning gastrointestinal stromal tumours (GISTs) over 30 years. Discussion. GISTs have been, for more than 30 years, the subject of considerable controversy regarding their line of differentiation as well as the prediction of their behaviour. Furthermore, once they spread within the peritoneal cavity, they are extremely hard to control. The recent findings of c-Kit mutations and the immunohistochemical detection of the product of this gene, KIT or CD 117, in the mainly non- myogenic subset of this family of tumours, has led to a reappraisal of this group of lesions, which, with some exceptions, is now thought to be derived from the interstitial cells of Cajal, and this has facilitated a clearer definition of their pathological spectrum. In this article, we review chronologically the evolution of the concept of GIST with the gradual application of electron microscopy, immunohistochemistry, DNA ploidy analysis. We discuss the impact of these techniques on the pathological assessment and clinical management of GISTs.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Histiocytic sarcoma

vedi documento allegat