The 2020 WHO Classification of Soft Tissue Tumours: news and perspectives

Dermatofibrosarcoma Protuberans in Children

OPINION STATEMENT

Paediatric dermatofibrosarcoma protuberans (DFSP) is a rare soft tissue malignant tumour which displays aggressive local behaviour and has low metastatic potential. The diagnosis is often delayed as DFSP is usually mistaken for other skin conditions, particularly in the early stages of disease. DFSP tends to follow an indolent course after the initial presentation with what is often described as a "rubbery lump". As the disease progresses, the lump tends to enlarge, change colour, and exhibit a more nodular consistency. In rare cases, DFSP can present as an ulcerated exophytic lesion or a depressed area of skin, making diagnosis even more challenging. A high index of suspicion is warranted for early diagnosis, and referral to a specialist unit with expertise in both oncologic resection and reconstruction. DFSP tumours arise from the dermis and grow with finger-like projections. Therefore, in cosmetically sensitive or functionally important locations, an excision and analysis technique that assesses all excision margins is the gold standard of care. Slow Mohs technique performed with en bloc excision is a well-tolerated option for oncologic resection of the tumour. Mohs technique can also be considered but can be challenging in children for reasons explained below. As an alternative, depending on the anatomical location, tumours can be excised with a wide local excision. While an excision technique that incorporates the deep fascia with a 3-cm peripheral margin is acceptable in adults, planning of the excision margin in children should involve consideration of preoperative imaging with MRI, site of the tumour, age, and physical built of the child. Patients should be offered all treatment options considering the local outcomes, available expertise, and cost. A multidisciplinary approach and good communication between team members is crucial. Close collaboration with a pathologist who is familiar with sectioning technique that allows margin control is of paramount importance. Soft tissue reconstruction should be performed immediately after oncologic clearance, although a staged approach may be required. Adjuvant radiotherapy should be avoided in children due to the long-term risk of secondary malignancies and potential for growth disruption.

NTRK Fusions Detection in Paediatric Sarcomas to Expand the Morphological Spectrum and Clinical Relevance of Selected Entities

Undifferentiated round cell sarcomas (URCS) of soft tissue and bone and tumours of uncertain differentiation (TUD) are commonly ascribed to a subset of neoplasms with low frequency of NTRK gene fusions. However, more recently NTRK-rearranged round and spindle cell tumours have been noted in case reports and in limited or heterogeneous cohorts. The aim of our study was to investigate the presence of NTRK gene fusions in a large retrospective cohort of paediatric URCS and TUD after a systematic review of the diagnosis, according to the recently updated WHO classification scheme. One-hundred and five patients with diagnosis of URCS or TUD, involving the bone or soft tissue, were retrospectively evaluated. After the case selection and the histopathological review of the case cohort, pan-Trk immunohistochemistry (IHC) testing was performed on formalin-fixed paraffin-embedded (FFPE) tissues. Tumour RNA was extracted from FFPE tissue and subjected to next-generation sequencing (NGS) library preparation, using a 10-gene NGS fusion panel, sequenced on an Illumina MiSeq. The NGS-positive cases were further confirmed by real-time PCR. On immunohistochemical screening, 12/105 (11.4%) cases were positive using the pan-Trk antibody, showing three different staining patterns with the cytoplasmic distribution being most common. Molecular analysis using NGS and confirmed by the real-rime PCR detected two positive cases for the ETV6-NTRK3 fusion. The histological pattern of the two positive cases, together with the demonstration of the NTRK rearrangement, leaded to re-classify these previously not otherwise specified sarcomas with uncertain differentiation into the emerging category of NTRK-rearranged neoplasms. In addition, we found the two NTRK fused neoplasms showing a clinical indolent course, in contrast with literature.

Large retroperitoneal atypical spindle cell lipomatous tumor, an extremely rare neoplasm: A case report

BACKGROUND

Atypical spindle cell lipomatous tumor (ASLT) is a rare soft tissue neoplasm with a low potential for malignancy. ASLT frequently occurs in the limb and limb girdles. However, large retroperitoneal ASLTs are extremely rare. There was no concrete case report of retroperitoneal ASLTs.

CASE SUMMARY

An 18-year-old woman presented with abdominal pain and a palpable mass. Abdominal computed tomography revealed a large fatty mass that was approximately 30 cm in size and filled the entire abdominal cavity. Surgical excision was indicated. The tumor did not invade the adjacent organs. The pelvic cavity was then too narrow to dissect smoothly. The mass was successfully excised without tumor rupture or adjacent organ injury. Microscopically, the neoplasm was a well-differentiated adipocytic neoplasm. Immunohistochemical staining showed that the spindle cells were positive for CD34 and desmin, in addition to multifocal positivity for S100 protein. These histological features were consistent with an ASLT. The patient’s postoperative course was uneventful. At the 12-mo follow-up, no evidence of recurrence or metastasis was observed.

CONCLUSION

To the best of our knowledge, our study is the first concrete report of a large retroperitoneal ASLT in the English literature. In the large retroperitoneal ASLT located in the pelvic cavity, which made it too narrow and tight to dissect, complete excision is difficult but very important because of recurrence risk. Although large retroperitoneal ASLTs are considered extremely rare, their detection is important for accurate evaluation and management. Owing to their significant rarity, retrospective multicenter case studies are required to determine the clinicopathologic characteristics.

Targetable Pathways in the Treatment of Retroperitoneal Liposarcoma

Liposarcoma (LPS) is the most prevalent soft tissue sarcoma histological subtype. When it occurs in the abdomen the overall survival rate is as low as 10% at 10 years and is fraught with high rates of recurrence, particularly for the more aggressive dedifferentiated subtype. Surgery remains the mainstay of treatment. Systemic therapies for the treatment of metastatic or unresectable disease have low response rates. Deep understanding of well-differentiated and de-differentiated LPS (WDLPS and DDLPS, respectively) oncologic drivers is necessary for the development of new efficacious targeted therapies for the management of this disease. This review discusses the current treatments under evaluation for retroperitoneal DDLPS and the potential targetable pathways in DDLPS.

Primary Hepatic Epithelioid Hemangioendothelioma Masquerading as a Hepatic Abscess With Infective Picture: A Case Report

Hepatic endotheiloid hemangioendothelioma (EHE) commonly presents with multilobar involvement with locally aggressive behavior. In most cases, it presents with right upper quadrant abdominal pain, hepatomegaly, and weight loss with metastasis commonly to the lung. We present a 33-year-old woman with hepatic EHE with an initial presentation mimicking hepatic abscess and imaging findings misleading for metastatic liver lesions. It was confirmed on pathology with immunohistochemistry, but the patient could not survive due to her late presentation and the presence of metastatic lesions in the lung.

Potential anticancer properties and mechanisms of thymoquinone in osteosarcoma and bone metastasis

Despite great advances, therapeutic approaches of osteosarcoma, the most prevalent class of preliminary pediatric bone tumors, as well as bone-related malignancies, continue to demonstrate insufficient adequacy. In recent years, a growing trend toward applying natural bioactive compounds, particularly phytochemicals, as novel agents for cancer treatment has been observed. Bioactive phytochemicals exert their anticancer features through two main ways: they induce cytotoxic effects against cancerous cells without having any detrimental impact on normal cell macromolecules such as DNA and enzymes, while at the same time combating the oncogenic signaling axis activated in tumor cells. Thymoquinone (TQ), the most abundant bioactive compound of Nigella sativa, has received considerable attention in cancer treatment owing to its distinctive properties, including apoptosis induction, cell cycle arrest, angiogenesis and metastasis inhibition, and reactive oxygen species (ROS) generation, along with inducing immune system responses and reducing side effects of traditional chemotherapeutic drugs. The present review is focused on the characteristics and mechanisms by which TQ exerts its cytotoxic effects on bone malignancies.

Retroperitoneal Sarcoma Care in 2021

Soft-tissue sarcomas are biologically heterogenous tumors arising from connective tissues with over 100 subtypes. Although sarcomas account for <1% of all adult malignancies, retroperitoneal sarcomas are a distinct subgroup accounting for <10% of all sarcomatous tumors. There have been considerable advancements in the understanding and treatment of retroperitoneal sarcoma in the last decade, with standard treatment consisting of upfront primary surgical resection. The evidence surrounding the addition of radiation therapy remains controversial. There remains no standard with regards to systemic therapy, including immunotherapy. Adjunctive therapy remains largely dictated by expert consensus and preferences at individual centers or participation in clinical trials. In this 2021 review, we detail the anatomical boundaries of the retroperitoneum, clinical characteristics, contemporary standard of care and well as recent advancements in retroperitoneal sarcoma care. Ongoing international collaborations are encouraged to advance our understanding of this complex disease.

Glomangiomatosis of the lower leg

This paper demonstrates a case of multiple glomangiomas, or glomangiomatosis, including clinical presentation, imaging appearances, and subsequent management. Differentiating features from typical glomus tumors are described. To the best of our knowledge, this is the first reported case of a glomangioma involving the distal tibiofibular syndesmosis.

Undifferentiated pleomorphic sarcoma of the pancreas: a rare case report and literature review

Background

Primary undifferentiated pleomorphic sarcoma (UPS) of the pancreas is an exceedingly rare malignant tumor, with only 15 cases have been reported in the medical literature. At present, clinicians have poor recognition of the tumor, the epidemiology, diagnosis, and treatment of this disease have yet not been established.

Case presentation

In this report, we depict the clinical and imaging characteristics of a 37-year-old man presenting with a primarily cystic UPS. The patient complained of epigastric pain and distention over 20 days. Abdominal CT and pancreatic magnetic resonance imaging revealed cystic and cystic solid masses in the pancreatic body and tail. An abdominal ultrasound echogram revealed the mass in the body of the pancreas to be cystic with separation echo inside, and the wall was thick, not smooth. Besides, a hypoechoic mass was seen in the tail area of the pancreas with an inhomogeneous echoic pattern, containing small patches of no echo zone in the central. Microscopically, spindle fibroblast-like cells are arranged in a characteristic storiform pattern with pleomorphic and multinucleated cells. Immunohistochemically, tumor cells were positive for CD68 and vimentin. Seven months postoperatively, he was diagnosed with pulmonary lymph node metastasis and died 5 months later. Combined with this case report, we also reviewed the literature regarding UPS of the pancreas.

Conclusions

As we know, this is the first report on ultrasonography findings of pancreatic UPS. Despite there are no distinctive manifestation of UPS, a solid cystic lesion on ultrasonography or a hypodense area in the lesion on T2-weighted imaging, should be considered for differential diagnosis with pancreatic UPS. We believe this article may add some ideas into the diagnosis and therapy of patients with this tumor.

Primary Malignant Peripheral Nerve Sheath Tumors of Bone: A Clinicopathologic Reappraisal of 8 Cases

Primary spindle cell and pleomorphic sarcomas of bone represent an exceedingly rare group of mesenchymal malignancies that include "soft tissue" histotypes, as malignant peripheral nerve sheath tumour. Outside the head and neck region, only 36 cases of primary malignant peripheral nerve sheath tumour of bone have been described. We retrieved from our archives eight cases of primary malignant peripheral nerve sheath tumour of bone arising outside the head and neck region, describing their clinical, radiological, and morphologic features. Our series, in which all but one patient died of diseases after a median of seven months, confirms that primary malignant peripheral nerve sheath tumours of bone are aggressive tumours. Pathologists should be aware of this rare histotype. More aggressive and active adjuvant treatments should be investigated.

Primary orbital pleomorphic liposarcoma in a child: A case report

Purpose

To report a rare case of primary orbital pleomorphic liposarcoma and present a relevant literature review.

Observations

An 11-year-old boy presented with an enlarging, painless lower right eyelid mass that was noted 4 months ago. Imaging revealed a 3.2 × 2.1 × 3.7-cm-sized well-circumscribed lobulated mass. Biopsy revealed a pleomorphic spindle cell neoplasm that was consistent with a pleomorphic liposarcoma. A systemic evaluation found no evidence of distant metastasis. Despite four chemotherapy cycles, the mass size increased at follow-up. Total orbital exenteration was performed 1 year after confirming a diagnosis of pleomorphic liposarcoma. At the 6-month follow-up, the patient was alive with no signs of recurrence.

Conclusions

Pediatric pleomorphic liposarcoma is a very rare entity. Its definite diagnosis relies on histopathological results. In the absence of systemic metastasis, total orbital exenteration is the optimal approach for local control.

Accuracy of core needle biopsy for histologic diagnosis of soft tissue sarcoma

The biopsy technique of choice in soft tissue sarcoma (STS) diagnosis is controversial. We examined the diagnostic accuracy of percutaneous core needle biopsy (CNB) and compared it to open incisional biopsy. A retrospective study included 91 incisional biopsies and 102 CNBs. A pair-match investigation was conducted on 19 patient pairs, comparing sensitivity, specificity, and diagnostic accuracy. Furthermore, we investigated the role of molecular pathology in sarcoma diagnostics. In 81/91 (89%) patients with incisional biopsy, the entity was confirmed by definitive pathology, whereas this was the case in 89/102 (87%) CNB patients (p = 0.52). Grading remained unchanged in 46/55 (84%) of incisional and 54/62 (87%) of CNBs (p = 0.61). The pair matched analysis showed that the correct entity was determined in 96% of incisional and 97.6% of core needle biopsies. The time between the initial consultation and the interdisciplinary tumor board's treatment recommendation was shorter in core needle biopsies (8.37 vs. 15.63 days; p < 0.002). Incisional biopsies led to two wound infections and one hematoma, whereas wound infection occurred in one patient after CNB. CNB leads to faster diagnosis while reaching the same histological accuracy and is less burdensome for patients. Still, surgeons need to remain aware of the possibility of biopsy failure.

Primary spindle cell sarcoma of gallbladder: An unusual case report and a literature review

INTRODUCTION

Primary spindle cell sarcoma of the gallbladder is a rare condition.

PATIENT CONCERNS

A 67-year-old woman was admitted to a local hospital with a chief complaint of abdominal pain in the right upper quadrant for the past 2 months.

DIAGNOSIS AND INTERVENTION

Surgical resection was performed following the diagnosis of primary gallbladder sarcoma with local hepatic metastasis. Histological examination confirmed a diagnosis of primary spindle cell sarcoma and hepatic metastasis with simultaneous cholecystolithiasis.

OUTCOMES

Adjuvant chemoradiation therapy was not performed because the patient refused treatment. Three months after the surgery, a relapsed lesion was diagnosed. The patient underwent transcatheter arterial chemoembolization.

CONCLUSIONS

The disease should be differentially diagnosed from gallbladder carcinoma or carcinosarcoma with hepatic metastasis. An aggressive surgical approach should be based on a balance between the risk of surgery and the outcome.

Undifferentiated Pleomorphic Sarcoma Presenting With Cardiac Tamponade: A Case Report and Review

Soft tissue sarcomas (STS) comprise a large group of heterogeneous malignant tumors that form approximately 1% of all adult malignancies. Most sarcomas originate from soft tissue and the rest arise from the bone. Undifferentiated pleomorphic sarcoma (UPS) is an aggressive tumor that usually presents as an asymptomatic subcutaneous mass that exhibits rapid growth with unremarkable skin findings. The diagnosis is usually made with histopathology or immunohistochemistry; once the diagnosis is confirmed, evaluation and workup of the primary tumor, lymph nodes, and metastasis should be made. Treatment is stage-dependent but generally involves en-bloc resection followed by a review of pathology with a discussion of the benefits of adjuvant radiation or chemotherapy. Here, we discuss a case of a 77-year-old patient who presented with a large mass over the right shoulder and echocardiographic findings of cardiac tamponade.

Establishment and evaluation of retroperitoneal liposarcoma patient-derived xenograft models: an ideal model for preclinical study

Retroperitoneal liposarcoma (RLPS) is one of the most common subtypes of retroperitoneal soft tissue sarcomas. It is characterized by poor sensitivity to radiotherapy and chemotherapy and a low success rate of complete surgical resection. However, there are few reliable preclinical RLPS models for target discovery and therapy research. In this study, we aimed to establish RLPS patient-derived xenograft (PDX) models that are useful for biological research and preclinical drug trials. A total of 56 freshly resected RLPS tissues were subcutaneously transplanted into non-obese diabetic-severe combined immune deficient (NOD-SCID) mice, with subsequent xenotransplantation into second-generation mice. The tumor engraftment rate of first generation PDXs was 44.64%, and higher success rates were obtained from implantations of dedifferentiated, myxous, pleomorphic, high-grade liposarcomas and those with retroperitoneal organ infiltration. The first- and second- generation PDX models preserved the histopathological morphology, gene mutation profiles and MDM2 amplification of the primary tissues. PDX models can also provide the benefit of retaining original tumor biology and microenvironment characteristics, such as abnormal adipose differentiation, elevated Ki67 levels, high microvessel density, cancer-associated fibroblast presence, and tumor-associated macrophage infiltration. Overall survival (OS) and disease-free survival (DFS) of patients with successful first-generation PDX engraftment were significantly poorer than those with failed engraftment. Treatment with MDM2 inhibitor RG7112 significantly suppressed tumor growth of DDLPS PDX in mice. In conclusion, we successfully established RLPS PDX models that were histologically, genetically, and molecularly consistent with the original tissues. These models might provide opportunities for advancing RLPS tumor biology research, facilitating the development of novel drugs, particularly those targeting MDM2 amplification, adipose differentiation process, angiogenesis, cancer-associated fibroblasts, and so on.

Pyroptosis-Related Gene Signature Is a Novel Prognostic Biomarker for Sarcoma Patients

Sarcoma is a rare and an extremely aggressive form of cancer that originates from mesenchymal cells. Pyroptosis exerts a dual effect on tumours by inhibiting tumour cell proliferation while creating a microenvironment suitable for tumour cell development and proliferation. However, the significance of pyroptosis-related gene (PRG) expression in sarcoma has not yet been evaluated. Here, we conduct a retrospective analysis to examine PRG expression in 256 sarcoma samples from The Cancer Genome Atlas database. We identified the PRGs that had a significant correlation with overall patient survival in sarcoma by performing a univariate Cox regression analysis. Subsequently, we conducted a LASSO regression analysis and created a risk model for a six-PRG signature. As indicated from the Kaplan–Meier analysis, this signature revealed a significant difference between high- and low-risk sarcoma patients. A receiver operating characteristic curve analysis confirmed that this signature could predict overall patient survival in sarcoma patients with high sensitivity and specificity. Gene ontology annotation and Kyoto Encyclopaedia of Genes and Genomes pathway enrichment analyses revealed that five independent PRGs were closely associated with increased immune activity. Moreover, we also deciphered that increased number of immune cells infiltrated the tumour microenvironment in sarcoma. In brief, the PRG signature can effectively act as novel prognostic biomarker for sarcoma patients and is associated with the tumour immune microenvironment.

The contribution of Juan Rosai to the pathology of soft tissue tumors

The conceptual evolution in the field of soft tissue tumor pathology has been mostly driven by a relatively small group of individuals that includes giants of the past and the present such as James Ewing, Raffaele Lattes, Arthur Purdy Stout, Franz Enzinger, Sharon Weiss, Lennart Angervall, Harry Evans, Marku Miettinen, and Christopher Fletcher. Juan Rosai, not only exerted an immense impact on surgical pathology in general, but in consideration of his unique talent in identifying novel clinicopathologic entities, has also contributed remarkably to current understanding of mesenchymal neoplasms. The creation of desmoplastic small round cell tumor certainly ranks among his most relevant efforts, although he actually put his mark on a broad variety of soft tissue lesions, including vascular neoplasms. It would be impossible to include in a single article all the entities that he created or contributed to refine; therefore, this review is limited to a selection of what we believe represent true milestones.

Natural History and Treatment Strategies of Advanced PEComas: A Systematic Review

Simple Summary

In this article, we review the clinical features of advanced PEComas and show the diversity of reported data among authors, emphasizing the heterogeneity of molecular characterization and treatment strategy. Based on clinical data collected from 124 case reports, metastatic disease at diagnosis and a grouped version of the Bleeker’s risk category were the only factors significantly associated with death. Due to a significant number of missing data or short follow-ups, results regarding prognostic factors should, however, be interpreted with caution.

Abstract

PEComas is a family of rare mesenchymal tumors. This systematic review aims to better understand the natural history of advanced PEComas. After a search on the PubMed database and main oncology meeting libraries according to the PRISMA guidelines, 88 articles reported in the English literature were included. Data on clinical and histological features, treatments and outcomes were collected. To identify risk factors, univariate and multivariate analyses were performed. Seven cohorts of patients and 124 individual patients were identified. Focusing on case reports, most patients were metastatic, and the median overall survival (OS) of the entire cohort was 60 months (95%CI 33; NA). Risk factors significantly associated with OS in the multivariate analysis were the presence of metastasis at diagnosis (HR: 2.59, 95%CI 1.06; 6.33, p = 0.036) and the grouped-Bleeker’s risk category (HR: 4.66; 95%CI 1.07; 20.19; p = 0.039). In the metastatic population, only the presence of lymph node metastasis was associated with OS (HR: 3.11; 95%CI 1.13; 8.60, p < 0.05). Due to a lack of events, it was not possible to conclude on other factors. This review of the literature highlights the heterogeneity of literature data and shows the great diversity of clinical management strategies.

Locally aggressive rarely metastazing tumors and low-grade sarcoma in children, adolescents and young adults: The benefits of a national network

INTRODUCTION

Complete surgical resection constitutes the mainstay of treatment for locally aggressive, rarely metastazing tumor and low-grade soft tissue sarcomas (LAS). Local relapse is the most common tumor event, especially in the presence of positive margins (R1 margins). The aims of this study are to assess the impact of the national network on patient care and to evaluate the role of immediate re-excision in children, adolescents and young adults with incompletely resected LAS.

METHODS

National retrospective multicenter study of all young patients (≤25 years) included in the Sarcoma "ConticaBase" treated for LAS between 2005 and 2017 for whom pathology/biology review was available via the national NETSARC + network.

RESULTS

A total of 96 patients were identified (median age: 16 years). Tumors were localized in 99% of cases (1 N+ tumor). With a median follow-up of 4.7 years (range: 0.1-11.9), eight local relapses and two distant metastases were observed. No patient died. Overall 5-year event-free survival (EFS) was 90.4% [95%CI, 84.3-97]. Five year EFS for R1 patients (n = 51) with (n = 24) and without (n = 27) immediate re-excision was 90.5% [95%CI, 78.8-100.0] and 80.3% [95%CI, 64.7-99.9], respectively (p = 0.34). The 37 patients directly treated in a reference center more commonly had a diagnostic biopsy (78% vs. 21%; p < 0.001), more complete surgery (R0: 65% vs. 14%; p < 0.001) and less commonly underwent re-excision (16% vs. 54%; p < 0.001).

CONCLUSIONS

This large series indicates that LAS are rare in young patients and have a favorable prognosis. Immediate management in reference centers is associated with better standard of care. The main tumor events are local relapses.

Undifferentiated Small Round Cell Sarcoma of the Postcricoid Region of the Hypopharynx: A Rare Case Report and Review of the Literature

Undifferentiated small round cell sarcoma (USRCS) is a rare malignant tumor. No reports about USRCS of the postcricoid region of the hypopharynx are available, and its clinical features and treatment guidelines remain undefined. We report a case of USRCS of the postcricoid region of the hypopharynx with treatment of surgery and radiotherapy. A 50-year-old man presented with a 4.9 cm x 3.7 cm tumor in the postcricoid region of the hypopharynx. It was diagnosed as USRCS. The tumor showed small round cells and positive immunoexpression of CD56, Cyclin D1, TLE1 and CD99, but no rearrangement or fusion of EWSR1, SS18, CIC, and BCOR. The patient underwent radiotherapy after surgery, without signs of tumor progression and metastasis at the 9-month follow-up. In conclusion, USRCS of postcricoid region of hypopharyngeal is ultra-rare. To make diagnosis, pathological examination is necessary. Surgery followed by radiotherapy might offer an optional treatment for USCRS.

Reconstruction of the chest wall after resection of malignant peripheral nerve sheath tumor: A case report

BACKGROUND

Malignant peripheral nerve sheath tumors (MPNSTs) are a group of rare and aggressive sarcomas that often arise from major peripheral nerves and represent a notable challenge to efficacious treatment. MPNSTs can occur in any body surface and visceral organs with nerve fiber distribution. The treatment options for MPNSTs include surgery, chemotherapy, and adjuvant radiotherapy.

CASE SUMMARY

A 26-year-old female cellist presented with chest pain on her left side when she squatted to lift the cello. One week later, a chest X-ray was performed and revealed fracture of the fourth rib on the left side. Three months later, the patient inadvertently touched a mass on the left side of the chest wall. Chest computed tomography (CT) three-dimensional reconstruction of the ribs revealed bone destruction of the fourth rib on the left side with a soft tissue mass shadow measuring 5.7 cm × 3.7 cm. CT-guided puncture biopsy of the tumor showed that heterotypic cells (spindle cells) tended to be nonepithelial tumor lesions. PET-CT demonstrated bone destruction and a soft tissue mass with avid 18F-fluorodeoxyglucose activity (SUV_max7.5) in the left fourth rib. The tumor of the left chest wall was resected under general anesthesia, and reconstruction of the chest wall was performed. The postoperative pathological report exhibited an MPNST.

CONCLUSION

MPNSTs are relatively chemo-insensitive tumors. The mainstay of treatment for MPNSTs remains resection with tumor-free margins.

MRI and CT features of a malignant myoepithelioma of the scrotum: A case report and literature review

Malignant myoepithelioma of the scrotum is extremely rare. We report the case of a 51-year-old man with malignant myoepithelioma of the scrotum, wherein computed tomography and magnetic resonance imaging revealed a lobulated soft tissue mass with calcification, cystic component, and solid component with gradual contrast enhancement on dynamic contrast-enhanced scans. The patient presented with scrotal induration, and there was no elevation of tumor markers and no evidence of a metastatic lesion on computed tomography and magnetic resonance imaging. Histopathological examination of the resected scrotal specimen confirmed a well-circumscribed solid tumor with septa, a small area of hemorrhage, and necrosis. The subsequent diagnosis was malignant myoepithelioma of the scrotum. This case shows that scrotal malignant myoepithelioma might appear as a well-defined lobulated mass with cystic regions. We conjecture that the enhancement pattern and apparent diffusion coefficient values can be potential markers for scrotal myoepithelial tumors.

Molecular Determinants of Soft Tissue Sarcoma Immunity: Targets for Immune Intervention

Soft tissue sarcomas (STSs) are a family of rare malignant tumors encompassing more than 80 histologies. Current therapies for metastatic STS, a condition that affects roughly half of patients, have limited efficacy, making innovative therapeutic strategies urgently needed. From a molecular point of view, STSs can be classified as translocation-related and those with a heavily rearranged genotype. Although only the latter display an increased mutational burden, molecular profiles suggestive of an “immune hot” tumor microenvironment are observed across STS histologies, and response to immunotherapy has been reported in both translocation-related and genetic complex STSs. These data reinforce the notion that immunity in STSs is multifaceted and influenced by both genetic and epigenetic determinants. Cumulative evidence indicates that a fine characterization of STSs at different levels is required to identify biomarkers predictive of immunotherapy response and to discover targetable pathways to switch on the immune sensitivity of “immune cold” tumors. In this review, we will summarize recent findings on the interplay between genetic landscape, molecular profiling and immunity in STSs. Immunological and molecular features will be discussed for their prognostic value in selected STS histologies. Finally, the local and systemic immunomodulatory effects of the targeted drugs imatinib and sunitinib will be discussed.

Primary Synchronous Ipsilateral Renal Fibrosarcoma and Renal Pelvic Carcinoma: A Case Report and Literature Review

Renal fibrosarcoma is a rare tumor, with only a few cases reported so far, and simultaneous occurrence of ipsilateral renal fibrosarcoma and renal pelvic carcinoma in a patient is extraordinarily rare. A 66-year-old man admitted to our hospital with right renal percutaneous nephrostomy and recurrent fever. And the patient underwent laparoendoscopic nephrectomy and partial ureterectomy for pyonephrotic nonfunctioning kidneys. Postoperative pathology showed fibrosarcoma of right kidney and carcinoma of the renal pelvis. This is the first case of simultaneous occurrence of ipsilateral renal fibrosarcoma and renal pelvic carcinoma in a patient. The diagnosis of fibrosarcoma is one of ultimate immunohistologic exclusion, because there are no specific immunologic markers for fibroblasts. Electron microscopy combined with light microscopy and IHC is helpful for the case of renal fibrosarcoma which is difficult to diagnose. Clinically, radical nephrectomy is the main strategy for primary localized renal fibrosarcoma. At present, it is still necessary to carry out basic biology research to better understand etiology and therapeutical strategy of renal fibrosarcoma.

Malignant fibrous histiocytoma of the floor of mouth: a case report and review of the literature

Malignant fibrous histiocytoma (MFH) is the most common soft tissue sarcoma in late adulthood and usually occurs in the limbs, trunk, and peritoneum. Less than 10% of MFH cases occur in the head and neck region. The clinical manifestations and pathological features of MFH are atypical, and it is difficult to make a clinical diagnosis. We describe a rare case of MFH of the floor of mouth and provide our diagnosis and treatment experiences. Through this review, we also evaluate the origin, World Health Organization (WHO) classification, clinical presentations, pathological features, treatment methods, and prognosis of MFH. MFH may originate from fibroblasts or primitive mesenchymal cells. MFH was defined as undifferentiated pleomorphic sarcoma in the 2002 WHO classification of bone and soft tissue tumors. The most common manifestation of MFH is a painless enlarging nodule, often without overlying epidermal ulcers. Jaw lesions are usually found after displays of swelling, pain, paresthesia, and loose teeth. MFH is composed of pleomorphic spindle cells, usually with hemorrhage, necrosis, and lymphocyte infiltration. The main treatment method is surgical resection. Moreover, radiotherapy and chemotherapy have certain auxiliary effects. The local recurrence and distant metastasis of MFH are common, and the prognosis is poor. Therefore, determining the histopathological features of MFH and conducting appropriate immunohistochemical examinations are crucial in establishing the correct diagnosis. In-depth study is required in order to have a better understanding of head and neck MFH.

Meaningful engagement of the patient in rare cancer research: sarcoma as an exemplar

Patient advocates who understand scientific methods and proper research processes can bring valuable perspectives to modern research. This is particularly important in rare cancers like sarcoma as each patient becomes a precious source of information to better diagnose, understand the biology and the effect of treatment. Reviewing approaches used by other cancer patient advocates can provide valuable insights to develop effective research advocates in rare cancers such as sarcoma.

Skull Base Leiomyomas and Angioleiomyomas: A Systematic Literature Review and an Uncommon Case Report

BACKGROUND

Skull base leiomyomas (LMs) and angioleiomyomas (ALMs) are rare, and the understanding of this disease is limited. We present a systematic literature review of skull base LM and ALM and report a case of internal auditory canal (IAC) ALM.

METHODS

A systematic review was conducted following the PRISMA guidelines. PubMed and Embase were systematically queried for skull base LM and ALM, and Rayyan QCRI was used for the review. After applying exclusion criteria, individual articles were evaluated for quality control, data collection, and analysis. The presentation, management, and outcome of a 37-year-old man with a right-sided IAC ALM are described.

RESULTS

Of 68 unique entries, 27 studies were included. Thirty-four cases of skull base LM (n = 6) or ALM (n = 28) were identified. Average age at presentation was 45.1 ± 14.5 years, and 52.9% of patients were male. Tumor diameter was 2.75 ± 1.6 cm, with headaches being the most reported symptom. Commonly reported locations were the cavernous sinus and the external auditory canal. Only 3 cases of IAC ALM met the criteria for this review. All tumors were treated with surgery, and gross total resection was achieved in 27 patients. Radiation was given in 3 cases with subtotal resection.

CONCLUSIONS

Skull base LM and ALM are rare. Given the need for pathology, surgery has been the standard treatment for symptomatic skull base LM and ALM. It is important to understand the available data about this disease and consider it in the differential of skull base lesions.

Therapeutic options in inoperable ROS1-rearranged inflammatory myofibroblastic tumor of the tongue in a child: a case report and literature review

Inflammatory myofibroblastic tumor (IMT) is a rare borderline malignancy, usually treated with surgery only. Exceedingly rare cases of inoperable, recurrent, or metastatic IMTs pose a therapeutic challenge. We report successful treatment of a 7-year-old girl with an inoperable anaplastic lymphoma kinase (ALK)-negative IMT of the tongue. The patient underwent various anti-inflammatory (steroids, nonsteroidal anti-inflammatory drugs, clarithromycin) and antiproliferative (chemotherapy) therapies to enable tumor regression and complete resection. Ultimately, next-generation sequencing of the tumor revealed a TFG-ROS-1 translocation, allowing for an off-label targeted therapy with crizotinib. Crizotinib treatment caused slight tumor regression but evident change of its structure, allowing for complete non-mutilating resection. Two histopathology examinations revealed complete disappearance of neoplastic cells following therapy. The patient remains disease-free 22 months after the delayed surgery. In children with inoperable ALK-negative IMTs, molecular testing must be performed to identify other targetable oncogenic fusions, including TFG-ROS1.

Mesenchymal tumours of the gastrointestinal tract

Mesenchymal tumours represent a heterogenous group of neoplasms encopassing benign, intermediate malignancy, and malignant entities. Sarcomas account for approximately 1% of human malignancies. In consideration of their rarity as well as of intrinsic complexity, diagnostic accuracy represents a major challenge. Traditionally, mesenchymal tumours are regarded as lesions the occurrence of which is mostly limited to somatic soft tissues. However, the occurrence of soft tissue tumours at visceral sites represent a well recognized event, and the GI-tract ranks among the most frequently involved visceral location. There exist entities such as gastrointestinal stromal tumours (GIST) and malignant gastointestinal neuroectodermal tumors that exhibit exquisite tropism for the GI-tract. This review will focus also on other relevant clinico-pathologic entities in which occurrence at visceral location is not at all negligible.

Anlotinib: A Novel Targeted Drug for Bone and Soft Tissue Sarcoma

Bone and soft tissue sarcomas account for approximately 15% of pediatric solid malignant tumors and 1% of adult solid malignant tumors. There are over 50 subtypes of sarcomas, each of which is notably heterogeneous and manifested by remarkable phenotypic and morphological variability. Anlotinib is a novel oral tyrosine kinase inhibitor (TKI) targeting c-kit, platelet-derived growth factor receptors, fibroblast growth factor receptor, and vascular endothelial growth factor receptor. In comparison with the placebo, anlotinib was associated with better overall survival and progression-free survival (PFS) in a phase III trial of patients with advanced non-small cell lung cancer (NSCLC), albeit with cancer progression after two previous lines of treatment. Recently, the National Medical Products Administration approved anlotinib monotherapy as a third-line treatment for patients with advanced NSCLC. Additionally, a phase IIB randomized trial substantiated that anlotinib is associated with a significant longer median PFS in patients with advanced soft tissue sarcoma. Moreover, anlotinib is also effective in patients with advanced medullary thyroid carcinoma and metastatic renal cell carcinoma. Anlotinib has similar tolerability to other TKIs targeting vascular endothelial growth factor receptors and other tyrosine kinase-mediated pathways. However, anlotinib has a notably lower rate of side effects ≥grade 3 relative to sunitinib. This review discussed the remarkable characteristics and major dilemmas of anlotinib as a targeted therapy for sarcomas.

Toward a Personalized Therapy in Soft-Tissue Sarcomas: State of the Art and Future Directions

Soft-tissue sarcomas are rare tumors characterized by pathogenetic, morphological, and clinical intrinsic variability. Median survival of patients with advanced tumors are usually chemo- and radio-resistant, and standard treatments yield low response rates and poor survival results. The identification of defined genomic alterations in sarcoma could represent the premise for targeted treatments. Summarizing, soft-tissue sarcomas can be differentiated into histotypes with reciprocal chromosomal translocations, with defined oncogenic mutations and complex karyotypes. If the latter are improbably approached with targeted treatments, many suggest that innovative therapies interfering with the identified fusion oncoproteins and altered pathways could be potentially resolutive. In most cases, the characteristic genetic signature is discouragingly defined as "undruggable", which poses a challenge for the development of novel pharmacological approaches. In this review, a summary of genomic alterations recognized in most common soft-tissue sarcoma is reported together with current and future therapeutic opportunities.

Efficacy and safety of apatinib in the treatment of osteosarcoma: a single-arm meta-analysis among Chinese patients

Background

Osteosarcoma is a relatively rare malignant tumor with a high incidence in young people. The development of tyrosine kinase inhibitors has brought the treatment of osteosarcoma into a new stage. Apatinib, a tyrosine kinase inhibitor specifically targeting VEGFR2, has been increasingly reported as a treatment for osteosarcoma with promising outcome parameters, but there has been no systematic analysis of the treatment of osteosarcoma by apatinib.

Methods

A single-arm meta-analysis was performed, and published literature from PubMed, Web of Science, Embase, Cochrane Library, CNKI and Wan Fang databases as of March 1, 2021 was systematically retrieved. Quality assessment is carried out in accordance with a 20 item checklist form prepared by the Institute of Health Economics (IHE). Double arcsine transformation is performed to stabilize the variance of the original ratio. When I² > 50%, the random effect model is used to calculate the pooled parameters; otherwise, the fixed effect model is used. We conducted subgroup analysis according to age and apatinib dose.

Results

This meta-analysis included 11 studies of 356 Chinese patients with osteosarcoma. The pooled objective remission rate (ORR) of advanced or metastatic osteosarcoma treated by oral apatinib in Chinese patients was 0.27(95%CI = 0.18–0.38). The pooled disease control rate (DCR) was 0.57 (95%CI = 0.42–0.72). The pooled median progression-free survival (mPFS) and median total survival (mOS) were 5.18 months (95%CI = 4.03–6.33) and 10.87 months (95% CI = 9.40–12.33), respectively. More than 70% of adverse reactions were mild, the most common adverse reaction was hand-foot syndrome (HFMD), with an incidence of 0.46 (95%CI = 0.35–0.58), the second was hypertension, with an incidence of 0.40 (95%CI = 0.29–0.51).

Conclusions

The efficacy of apatinib in the treatment of osteosarcoma is competitive with current evidence, and it is worth noting that its low cost can significantly improve patient compliance and increase therapeutic value.

Myopericytoma in right inguinal region: A rare case report from Nepal

INTRODUCTION

Myopericytoma is a rare mesenchymal soft tissue tumor that originates from perivascular myoid cells and mostly benign in nature. With a slight male predisposition, it occurs more commonly in the lower extremities with an insidious and painless presentation. Contrary to the usual, our patient was with a rare presentation in the inguinal region with a dull aching pain.

CASE PRESENTATION

We herein report a case of a 64-year-old female patient with myopericytoma, the first of its kind reported in Nepal, present in the right inguinal region and surgically removed. The mass was single with dull aching pain, non-tender, globular, smooth, mobile, covered with skin and, had been slowly growing for 1 year and had started bleeding for 4 days. On complete surgical excision and subsequent biopsy, a nodule with thin-walled blood vessels and spindle-shaped cells having indistinct cell border, eosinophilic cytoplasm, and oval to spindle-shaped nucleus was observed, features consistent with those of myopericytoma.

DISCUSSION

Myopericytoma can occur in different sites in the body. Its differential diagnoses in the inguinal region include inguinal hernia, lipoma, or an inguinal lymphangioma. Histopathological analysis and immunohistochemistry (IHC) staining are used for diagnosis and confirmation.

CONCLUSION

Myopericytomas are rare and have a substantial propensity to be misdiagnosed as other soft tissue tumors such as sarcomas due to significant overlap in their presentation and histological features. Complete surgical excision of mass is the curative therapy.

Impact of Pathological Stratification on the Clinical Outcomes of Advanced Well-Differentiated/Dedifferentiated Liposarcoma Treated with Trabectedin

BACKGROUND

We previously showed that grading can prognosticate the outcome of retroperitoneal liposarcoma (LPS). In the present study, we aimed to explore the impact of pathological stratification using grading on the clinical outcomes of patients with advanced well-differentiated LPS (WDLPS) and dedifferentiated LPS (DDLPS) treated with trabectedin.

PATIENTS

We included patients with advanced WDLPS and DDLPS treated with trabectedin at the Fondazione IRCCS Istituto Nazionale dei Tumori between April 2003 and November 2019. Tumors were categorized in WDLPS, low-grade DDLPS, and high-grade DDLPS according to the 2020 WHO classification. Patients were divided in two cohorts: Low-grade (WDLPS/low-grade DDLPS) and high-grade (high-grade DDLPS).

RESULTS

A total of 49 patients were included: 17 (35%) in the low-grade cohort and 32 (65%) in the high-grade cohort. Response rate was 47% in the low-grade cohort versus 9.4% in the high-grade cohort (logistic regression p = 0.006). Median progression-free survival (PFS) was 13.7 months in the low-grade cohort and 3.2 months in the high-grade cohort. Grading was confirmed as an independent predictor of PFS in the Cox proportional-hazards regression multivariable model (adjusted hazard ratio low-grade vs. high-grade: 0.45, 95% confidence interval: 0.22-0.94; adjusted p = 0.035).

CONCLUSIONS

In this retrospective case series, sensitivity to trabectedin was higher in WDLPS/low-grade DDLPS than in high-grade DDLPS. If confirmed in larger series, grading could represent an effective tool to personalize the treatment with trabectedin in patients with advanced LPS.