Desmoplastic small round cell tumor (DSRCT) is an extremely rare, aggressive sarcoma affecting adolescents and young adults with male predominance. Generally, it originates from the serosal surface of the abdominal cavity. The hallmark characteristic of DSRCT is the EWSR1–WT1 gene fusion. This translocation up-regulates the expression of PDGFRα, VEGF and other proteins related to tumor and vascular cell proliferation. Current management of DSRCT includes a combination of chemotherapy, radiation and aggressive cytoreductive surgery plus intra-peritoneal hyperthermic chemotherapy (HIPEC). Despite advances in multimodal therapy, outcomes remain poor since the majority of patients present disease recurrence and die within three years. The dismal survival makes DSRCT an orphan disease with an urgent need for new drugs. The treatment of advanced and recurrent disease with tyrosine kinase inhibitors, such as pazopanib, sunitinib, and mTOR inhibitors was evaluated by small trials. Recent studies using comprehensive molecular profiling of DSRCT identified potential therapeutic targets. In this review, we aim to describe the current studies conducted to better understand DSRCT biology and to explore the new therapeutic strategies under investigation in preclinical models and in early phase clinical trials.

Resumo: Schwannomas são tumores benignos oriundos de células da bainha neural cuja apresentação intraóssea é rara. Estima-se que os schwannomas intraósseos representem 0,2% de todos os tumores ósseos. Schwannomas podem acometer diferentes ossos do esqueleto, como a mandíbula, o sacro, corpos vertebrais, a ulna, o úmero, o fêmur, a tíbia, a patela, a escápula, costelas e ossos da mão. Apenas quatro casos que acometeram o calcâneo foram descritos na literatura. No presente trabalho, os autores relatam o caso de um paciente masculino de 49 anos com dor no retropé direito e com exames de imagem que evidenciaram lesão osteolítica no calcâneo. O estudo histopatológico confirmou o diagnóstico de Schwannoma intraósseo. O tratamento de escolha foi ressecção intralesional com adjuvância local e substituição por polimetilmetacrilato e fixação com parafusos canulados. O paciente evoluiu de forma satisfatória no pós-operatório e, após 1 ano de evolução, encontra-se assintomático, com boa resposta funcional e sem evidência de doença. Com esse relato, os autores desejam chamar atenção para essa patologia rara, sua apresentação clínica, radiológica e patológica, além de reiterar a importância de incluir o schwannoma intraósseo dentre os diagnósticos diferenciais das lesões osteolíticas do calcâneo.

On the right and left sides of the thyroid, the parathyroid glands are presented in the form of four nodules in total, two apical and two basal¹ 1 Próspero JD, Baptista PPR, Amary MFC, Santos PPC. Paratireóides: estrutura, funções e patologia. Acta Ortop Bras. 2008;17(2):53-7. https://doi.org/10.1590/S1413-78522009000200011 https://doi.org/10.1590/S1413-7852200900... . Topographic variations are common—the parathyroid glands can be located near the larynx or even in the mediastinum, near the thymus¹ 1 Próspero JD, Baptista PPR, Amary MFC, Santos PPC. Paratireóides: estrutura, funções e patologia. Acta Ortop Bras. 2008;17(2):53-7. https://doi.org/10.1590/S1413-78522009000200011 https://doi.org/10.1590/S1413-7852200900... . Microscopically, they are made up of two main types of cells, clear and oxyphilic; the former secrete parathyroid hormone (PTH), and the latter have a still obscure function—all are arranged in a chordonal arrangement, interspersed with lobes of fatty tissue¹ 1 Próspero JD, Baptista PPR, Amary MFC, Santos PPC. Paratireóides: estrutura, funções e patologia. Acta Ortop Bras. 2008;17(2):53-7. https://doi.org/10.1590/S1413-78522009000200011 https://doi.org/10.1590/S1413-7852200900... ,² 2 Jambeiro JES, Guedes A, Mattos ESR, Guedes AAL, Freire ANM, Freire MDM, et al. Osteíte fibrose cística. Rev Cient HSI. 2023;7(1):18-30. .

In the differential diagnosis of bone tumors, the following parameters are relevant: age, onset and duration of symptoms, lesion location (affected bone), affected part of the bone, radiographic aspect, and tumor growth pattern.

Introduction: Desmoid Tumors (DT) are rare neoplasms with higher incidence in younger women. Methods: Retrospective, single-center analysis of patients with DT. Variables were age, sex, biopsy, treatment and recurrence. The disease-free survival (DFS) was calculated with the Kaplan-Meier method. Results: 242 patients were evaluated, mean age was 34 years, 70.7% women, 44.4% originated in the trunk/abdomen and 54.5% had size > 5cm. Surgery was performed in 70.2%, 31% with negative margin and only 57% with previous biopsy. Recurrence rate was 38% and 1,2,5-year DFS was 75.3%, 64.2%, 57.8%, respectively. Size (p = 0.018) and tumor location in the dorsum (p = 0.001), extremities (p = 0.003) and pelvis (p = 0.003) were related to higher relapse rate. Conclusion: our data reinforces the need to gather data from real world practice and the importance of awareness of DT and medical education about DT behavior and best approach due to the high rates of surgery and elevated number of patients treated without biopsy. Level of Evidence III; Retrospective Comparative Study.