Recurrent and metastatic cellular cutaneous fibrous histiocytoma: A case report and literature review.

Cutaneous fibrous histiocytoma (FH) is considered a benign dermal tumor. The cellular variant is rare and poorly documented. Besides presenting a high risk of local recurrence, it has a low but serious metastatic potential. We present a case of metastatic cellular FH and also review the literature on this tumor, given its unusual metastatic development. A 47-year-old male patient presented with a lesion in the anterior surface of the right thigh, which has been present since adolescence but had grown during last year. Anatomopathological evaluation revealed a cellular FH, and the lesion was completely removed. Six months later, tumor recurrence with multiple compartment muscle involvement and pulmonary metastasis were detected. Both lesions were completely resected and after 3 years of follow-up, the patient is asymptomatic and free of the disease. We conclude that FH should be carefully sampled to detect variants with high local recurrence rates or with some metastatic risk such as the cellular one. We recommend wide surgical resection and a close follow-up including chest x-rays or thorax computed tomography (CT) in all cellular FH cases with local recurrence.

Outcomes of Long Bones Treated With Carbon-Fiber Nails for Oncologic Indications: International Multi-institutional Study.

BACKGROUND: Intramedullary nail fixation is commonly used for prophylactic stabilization of impending and fixation of complete pathological fractures of the long bones. However, metallic artifacts complicate imaging evaluation for bone healing or tumor progression and postoperative radiation planning. Carbon-fiber implants have gained popularity as an alternative, given their radiolucency and superior axial bending. This study evaluates incidences of mechanical and nonmechanical complications. METHODS: Adult patients (age 18 years and older) treated with carbon-fiber nails for impending/complete pathological long bone fractures secondary to metastases from 2013 to 2020 were analyzed for incidences and risk factors of mechanical and nonmechanical complications. Mechanical complications included aseptic screw loosening and structural failures of host bone and carbon-fiber implants. Deep infection and tumor progression were considered nonmechanical. Other complications/adverse events were also reported. RESULTS: A total of 239 patients were included; 47% were male, and 53% were female, with a median age of 68 (IQR, 59 to 75) years. Most common secondary metastases were related to breast cancer (19%), lung cancer (19%), multiple myeloma (18%), and sarcoma (13%). In total, 17 of 30 patients with metastatic sarcoma received palliative intramedullary nail fixation for impending/complete pathological fractures, and 13 of 30 received prophylactic nail stabilization of bone radiated preoperatively to manage juxta-osseous soft-tissue sarcomas, where partial resection of the periosteum or bone was necessary for negative margin resection. 33 (14%) patients had complications. Mechanical failures included 4 (1.7%) structural host bone failures, 7 (2.9%) implant structural failures, and 1 (0.4%) aseptic loosening of distal locking screws. Nonmechanical failures included 8 (3.3%) peri-implant infections and 15 (6.3%) tumor progressions with implant contamination. The 90-day and 1-year mortalities were 28% (61/239) and 53% (53/102), respectively. The literature reported comparable failure and mortality rates with conventional titanium treatment. CONCLUSIONS: Carbon-fiber implants might be an alternative for treating impending and sustained pathological fractures secondary to metastatic bone disease. The seemingly comparable complication profile warrants further cohort studies comparing carbon-fiber and titanium nail complications.

Soft Tissue Aneurysmal Bone Cyst in the Sartorius Muscle of a 13-Year-Old Boy Mimicking Myositis Ossificans: Case Report.

INTRODUCTION: A soft tissue aneurysmal bone cyst is an extremely rare tumor. The objective of the article is to present the clinical, radiological, and histopathological features of a very unusual neoplasm of soft tissues. CASE REPORT: A 13-year-old male patient presented a painful, mobile, and rapidly growing mass on the posteromedial aspect of his left knee. Imaging studies revealed a mass that arose from the medial surface of the distal sartorius muscle, with extension to the subcutaneous fat tissue. It was a well-circumscribed solid tumor with a peripheral rim calcification on plain film, computerized tomography, and ultrasound (zonal phenomenon). On magnetic resonance imaging, a heterogenous mass on T1-weighted images (WI) and T2-WI was seen, with a peripheral hypointense rim in both sequences. An outstanding edema on T2-WI extending to the soft tissue and muscles of the medial compartment of the knee was detected. The mass was resected, and the "tumoral mimickers" histopathological and molecular (next-generation sequencing) diagnoses confirmed a soft tissue aneurysmal bone cyst. A follow-up showed that the patient was free of disease 12 months after surgery. CONCLUSION: Soft tissue aneurysmal bone cyst is a rare tumor. Appropriate clinical and radiological correlation should be performed to differentiate it from other tumor mimickers.

Therapeutic strategies and clinical evolution of patients with infantile fibrosarcoma: a unique paediatric case series

Background Infantile fibrosarcoma is the most frequent soft tissue sarcoma in newborns or children under one year of age. This tumour often implies high local aggressiveness and surgical morbidity. The large majority of these patients carry the ETV6–NTRK3 oncogenic fusion. Hence, the TRK inhibitor larotrectinib emerged as an efficacious and safe alternative to chemotherapy for NTRK fusion-positive and metastatic or unresectable tumours. However, real-world evidence is still required for updating soft-tissue sarcoma practice guidelines. Objective To report our experience with the use of larotrectinib in pediatric patients. Methods Our case series shows the clinical evolution of 8 patients with infantile fibrosarcoma under different treatments. All patients enrolled in this study received informed consent for any treatment. Results Three patients received larotrectinib in first line. No surgery was needed with larotrectinib, which led to the rapid and safe remission of tumours, even in unusual anatomical locations. No significant adverse effects were observed with larotrectinib. Conclusion Our case series supports that larotrectinib may be a therapeutic option for newborn and infant patients with infantile fibrosarcoma, especially in uncommon locations (AU)

Cytopathological findings of intranodal palisaded myofibroblastoma: Case report and review of the literature.

INTRODUCTION: Intranodal palisaded myofibroblastoma (IPM) is an exceedingly rare benign mesenchymal tumor of the lymph nodes. Magnetic resonance imaging (MRI) findings are unspecific, which may present diagnostic challenges to fine-needle aspiration cytology (FNAC). The histological and immunohistochemical features of IPM are unique. CASE REPORT: A previously healthy 40-year-old male patient presented a slow-growing solitary left inguinal mass. FNAC revealed clustered cells within a metachromatic stroma, single spindle cells without atypia, hemosiderin pigment, and siderophages. An MRI showed a central hyperintense septum in fat-suppressed, T2-weighted sequences. The excised lymph node contained central haphazard fascicles of spindle cells with focal nuclear palisading, hemosiderin pigment, extravasated erythrocytes, and hemorrhagic areas. Vimentin and smooth muscle actin were diffusely positive. Amianthoid collagen fibers were not clearly observed. CONCLUSION: IPM is an extremely rare mesenchymal benign intranodal tumor that should be included in the differential diagnosis of spindle cell lesions in the inguinal region.

Prospects and Advances in Adoptive Natural Killer Cell Therapy for Unmet Therapeutic Needs in Pediatric Bone Sarcomas.

Malignant bone tumors are aggressive tumors, with a high tendency to metastasize, that are observed most frequently in adolescents during rapid growth spurts. Pediatric patients with malignant bone sarcomas, Ewing sarcoma and osteosarcoma, who present with progressive disease have dire survival rates despite aggressive therapy. These therapies can have long-term effects on bone growth, such as decreased bone mineral density and reduced longitudinal growth. New therapeutic approaches are therefore urgently needed for targeting pediatric malignant bone tumors. Harnessing the power of the immune system against cancer has improved the survival rates dramatically in certain cancer types. Natural killer (NK) cells are a heterogeneous group of innate effector cells that possess numerous antitumor effects, such as cytolysis and cytokine production. Pediatric sarcoma cells have been shown to be especially susceptible to NK-cell-mediated killing. NK-cell adoptive therapy confers numerous advantages over T-cell adoptive therapy, including a good safety profile and a lack of major histocompatibility complex restriction. NK-cell immunotherapy has the potential to be a new therapy for pediatric malignant bone tumors. In this manuscript, we review the general characteristics of osteosarcoma and Ewing sarcoma, discuss the long-term effects of sarcoma treatment on bones, and the barriers to effective immunotherapy in bone sarcomas. We then present the laboratory and clinical studies on NK-cell immunotherapy for pediatric malignant bone tumors. We discuss the various donor sources and NK-cell types, the engineering of NK cells and combinatorial treatment approaches that are being studied to overcome the current challenges in adoptive NK-cell therapy, while suggesting approaches for future studies on NK-cell immunotherapy in pediatric bone tumors.

Therapeutic strategies and clinical evolution of patients with infantile fibrosarcoma: a unique paediatric case series.

BACKGROUND: Infantile fibrosarcoma is the most frequent soft tissue sarcoma in newborns or children under one year of age. This tumour often implies high local aggressiveness and surgical morbidity. The large majority of these patients carry the ETV6-NTRK3 oncogenic fusion. Hence, the TRK inhibitor larotrectinib emerged as an efficacious and safe alternative to chemotherapy for NTRK fusion-positive and metastatic or unresectable tumours. However, real-world evidence is still required for updating soft-tissue sarcoma practice guidelines. OBJECTIVE: To report our experience with the use of larotrectinib in pediatric patients. METHODS: Our case series shows the clinical evolution of 8 patients with infantile fibrosarcoma under different treatments. All patients enrolled in this study received informed consent for any treatment. RESULTS: Three patients received larotrectinib in first line. No surgery was needed with larotrectinib, which led to the rapid and safe remission of tumours, even in unusual anatomical locations. No significant adverse effects were observed with larotrectinib. CONCLUSION: Our case series supports that larotrectinib may be a therapeutic option for newborn and infant patients with infantile fibrosarcoma, especially in uncommon locations.

Sarcoma European and Latin American Network (SELNET) Recommendations on Prioritization in Sarcoma Care During the COVID-19 Pandemic.

BACKGROUND: The COVID-19 outbreak has resulted in collision between patients infected with SARS-CoV-2 and those with cancer on different fronts. Patients with cancer have been impacted by deferral, modification, and even cessation of therapy. Adaptive measures to minimize hospital exposure, following the precautionary principle, have been proposed for cancer care during COVID-19 era. We present here a consensus on prioritizing recommendations across the continuum of sarcoma patient care. MATERIAL AND METHODS: A total of 125 recommendations were proposed in soft-tissue, bone, and visceral sarcoma care. Recommendations were assigned as higher or lower priority if they cannot or can be postponed at least 2-3 months, respectively. The consensus level for each recommendation was classified as "strongly recommended" (SR) if more than 90% of experts agreed, "recommended" (R) if 75%-90% of experts agreed and "no consensus" (NC) if fewer than 75% agreed. Sarcoma experts from 11 countries within the Sarcoma European-Latin American Network (SELNET) consortium participated, including countries in the Americas and Europe. The European Society for Medical Oncology-Magnitude of clinical benefit scale was applied to systemic-treatment recommendations to support prioritization. RESULTS: There were 80 SRs, 35 Rs, and 10 NCs among the 125 recommendations issued and completed by 31 multidisciplinary sarcoma experts. The consensus was higher among the 75 higher-priority recommendations (85%, 12%, and 3% for SR, R, and NC, respectively) than in the 50 lower-priority recommendations (32%, 52%, and 16% for SR, R, and NC, respectively). CONCLUSION: The consensus on 115 of 125 recommendations indicates a high-level of convergence among experts. The SELNET consensus provides a tool for sarcoma multidisciplinary treatment committees during the COVID-19 outbreak. IMPLICATIONS FOR PRACTICE: The Sarcoma European-Latin American Network (SELNET) consensus on sarcoma prioritization care during the COVID-19 era issued 125 pragmatical recommendations distributed as higher or lower priority to protect critical decisions on sarcoma care during the COVID-19 pandemic. A multidisciplinary team from 11 countries reached consensus on 115 recommendations. The consensus was lower among lower-priority recommendations, which shows reticence to postpone actions even in indolent tumors. The European Society for Medical Oncology-Magnitude of Clinical Benefit scale was applied as support for prioritizing systemic treatment. Consensus on 115 of 125 recommendations indicates a high level of convergence among experts. The SELNET consensus provides a practice tool for guidance in the decisions of sarcoma multidisciplinary treatment committees during the COVID-19 outbreak.

Early Mechanical Failure of a Tumoral Endoprosthesic Rotating Hinge in the Knee: Does Bumper Wear Contribute to Hyperextension Failure?

BACKGROUND: Tumor surgeons use a variety of endoprosthetic designs for reconstruction after bone tumor resection. However, functional results and implant survival have not been evaluated for each design. Because the outcomes and failure modes (for example, implant breakage, loosening) may differ between prosthetic design types, it is important to examine the problems associated with different designs. Because of experiences in our practice, we became concerned about a surprisingly high frequency of device breakage with one particular design, and we wished to report on that experience. QUESTION/PURPOSES: (1) In a small series of patients, what proportion of a particular design (Zimmer® Segmental [Zimmer Inc, Warsaw, IN, USA]) of rotating-hinge endoprosthesis experienced implant breakage at short-term follow-up? (2) What patient symptoms were associated with this finding? (3) What is the function as assessed by Musculoskeletal Tumor Society (MSTS) score with the use of this implant before and after revision? METHODS: We treated 87 patients in our tertiary center from 1987 to 2014 who had sarcomas around the knee with wide resection and reconstruction with tumoral endoprosthesis; five patients were lost to follow-up. In all, 33 of the remanining 82 prostheses, treated from 1987 to 2006, were reconstructed with fixed-hinge designs. From 2006 to 2014, 49 patients were reconstructed with a knee endoprosthesis, and 48 of them had a rotating-hinge prosthesis. In our center, we mostly used four designs: 16 of 49 patients were reconstructed with GMRS (Stryker Howmedica, Kalamazoo, MI, USA), seven received the LPS™ (DePuy Synthes, Warsaw, IN, USA), 20 of 49 had the METS (Stanmore, Hertfordshire, UK), and six of 49 received the Zimmer Segmental. The focus of this report is on the six patients with the Segmental. We retrospectively gathered clinical and radiologic data from these six patients' records and we assessed radiographic images. We evaluated function with the MSTS score of the 49 patients. The median follow-up duration of the Segmental prosthesis reconstruction was 65 months (range 24 to 85). RESULTS: Three of the six patients had posterior instability and recurrent joint effusion on physical examination. Three patients who did not have hyperextension presented with restricted knee ROM. Six revision procedures were performed in three patients. The median MSTS score at 6 months for the Segmental® prosthesis was 15 of 30 (range 6 to 24). The score in the three patients who had posterior instability was 9 of 30 (range 6 to 15) and it improved to median 25 of 30 (range 19 to 30) 6 months after revision. The patients with the Segmental® prosthesis who did not undergo revision had a median MSTS score of 20 (range 16 to 24). CONCLUSIONS: The Zimmer Segmental rotating-hinge tumoral prosthesis underwent revision for implant breakage at short term in three of six patients after tumor resection and reconstruction of the knee. Bumper breakage was associated with posterior instability that was related to wear of the bushing blocking system. We are unaware of reports of these issues by other observers or in other prosthetic designs, but we feel larger registries should be created to see if this failure mechanism has been observed by others. If so, this design needs to be improved or the blocking system should be avoided.Level of Evidence Level IV, therapeutic study.

Reconstruction After Hemipelvectomy With the Ice-Cream Cone Prosthesis: What Are the Short-term Clinical Results?

BACKGROUND: Reconstruction after internal hemipelvectomy resection likely provides better function than hindquarter amputation. However, many reconstruction methods have been used, complications with these approaches are common, and function often is poor; because of these issues, it seems important to investigate alternative implants and surgical techniques. QUESTIONS/PURPOSES: The purposes of this study were (1) to identify the frequency of surgical site complications and infection associated with the use of the Ice-Cream Cone prosthesis for reconstruction after hemipelvectomy for oncological indications; (2) to evaluate the Musculoskeletal Tumor Society (MSTS) outcomes scores in a small group of patients treated with this implant in the short term; and (3) to quantify the surgical margins and frequency of local recurrence in the short term in this group of patients. METHODS: Between 2008 and 2013, one center performed a total of 27 internal hemipelvectomies for oncological indications. Of those, 23 (85%) were treated with reconstruction. Our general indications for reconstruction were patients whose pelvic stability was affected by the resection and whose general condition was sufficiently strong to tolerate the reconstructive procedure. Of those patients undergoing reconstruction, 14 (61%) were treated with an Ice-Cream Cone-style implant (Coned®; Stanmore Worldwide Ltd, Elstree, UK; and Socincer® custom-made implant for the pelvis, Gijón, Spain), whereas nine others were treated with other implants or allografts. The indications during this time for using the Ice-Cream Cone implant were pelvic tumors affecting the periacetabular area without iliac wing involvement. Of those 14, 10 were available for followup at a minimum of 2 years (median, 3 years; range, 2-5 years) unless a study endpoint (wound complication, infection, or local recurrence) was observed earlier. Study endpoints were ascertained by chart review performed by one of the authors. RESULTS: Surgical site complications occurred in five patients. Of those, two developed superficial infections with necrosis, two developed deep infections, and one patient developed wound necrosis without apparent infection. No prostheses were removed as a result of these complications [corrected]. Median MSTS score was 19 out of 30 when 0 is the worst possible result and 30 a perfect function and emotional status. Five of seven primary tumors had wide margin surgery and three of seven developed local recurrences by the end of the followup. CONCLUSIONS: Pelvic reconstruction with the Ice-Cream Cone prosthesis yielded fair functional results at short-term followup. Longer term surveillance is called for to see whether this implant will represent an improvement over available reconstructive alternatives such as allograft, custom-made implants, and saddle prostheses. We are cautiously optimistic and continue to use this implant when we need to reconstruct the periacetabular area in patients without Enneking Zone 1 involvement. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Are Biopsy Tracts a Concern for Seeding and Local Recurrence in Sarcomas?

BACKGROUND: A biopsy is the final step in the diagnosis of sarcomas. Complete resection of the biopsy tract traditionally has been recommended in musculoskeletal oncology guidelines, as that tract is considered potentially seeded with tumor cells. However, to our knowledge, the frequency and implications of contamination of the biopsy tract-specifically with respect to the likelihood of local recurrence-and the factors that affect cell seeding are not well described. QUESTIONS/PURPOSES: We asked: (1) How often are biopsy tracts contaminated with pathologically detectable tumor cells at the time of tumor resection? (2) What factors, in particular biopsy type (open versus percutaneous), are associated with tumoral seeding? (3) Is biopsy tract contamination associated with local recurrence? METHODS: This is a retrospective study of a database with patient data collected from a single center between 2000 and 2013. We treated 221 patients with sarcomas. A total of 27 patients (12%) were excluded and 14 (6%) were lost to followup. One hundred eighty patients finally were included in the analysis who either had biopsies at our center (112) or biopsies at outside institutions (68). Of those performed at our center, 15 (13%) were open and 97 (87%) were percutaneous; of those at outside centers, those numbers were 47 (69%) and 21 (31%) respectively. Median followup was 40 months (range, 24-152 months). During the study period, we generally performed percutaneous biopsies as a standard practice for the diagnosis of bone and soft tissue sarcomas and open biopsies were done when the percutaneous procedure failed to provide a histologic characterization. The mean age of the population was 48 years (range, 7-87 years); 60% were male; 42% had bone sarcomas. Nineteen patients had preoperative radiotherapy and 56 had postoperative radiotherapy. Fifty-seven patients received neoadjuvant chemotherapy and 73 had adjuvant chemotherapy. We determined what proportion of biopsy tracts were contaminated by pathologic analysis of the biopsy tract specimen; during the period in question, our routine practice was to excise the biopsy tract whenever possible at the time of the definitive resection. Using the logistic regression test and Mantel-Haenszel test, we compared open with percutaneous biopsies in terms of the proportion of those that were contaminated at our site and for outside referral biopsies separately, because we do not assume the level of expertise was the same (our site is a referral tumor center). We compared the local recurrence-free survival between patients with and without contamination and between open and percutaneous biopsies using the Kaplan Meier test, again separating those performed at our site from those referred for purposes of this analysis. RESULTS: Twenty-one of 180 biopsy tracts were contaminated (12%). Twenty of 62 (32%) of the open biopsies and one of 118 (0.8%) of the percutaneous core needle biopsies had cell seeding (odds ratio [OR], 56; 95% CI, 7-428; p < 0.001. One of 97 (1%) percutaneous biopsies performed in our center, and none of the 21 (0%) percutaneous biopsies performed in other centers had contaminated biopsy tracts (p = 0.047). Two of 15 (13%) open biopsies performed at our center and 18 of 41(38%) open biopsies performed at other centers had contaminated biopsy tracts (OR, 4; 95% CI, 1-7; p = 0.001). Four of 74 (5%) bone sarcomas and 18 of 106 (17%) soft tissue sarcomas had biopsy tract contamination (OR, 3; 95% CI, 1-10; p = 0.023). The local recurrence-free survival was longer for patients without contaminated tracts (mean, 107 months; 95% CI, 74-141 months) than for those with biopsy tract seeding (mean, 11 months; 95% CI, 1-20 months; p < 0.001). CONCLUSIONS: Open biopsies were associated with an increased risk of tumoral seeding of the biopsy site, and tumoral seeding was associated with an increased risk of local recurrence. However, it is possible that other factors, such as increased complexity of the tumor or a difficult location, influenced the decision to obtain an open biopsy. Even so, based on these results, we believe that higher risk of local recurrence may be caused by an incomplete biopsy tract resection. In our opinion, the percutaneous biopsy with neoadjuvant or adjuvant therapy is the preferred method of biopsy at our center. LEVEL OF EVIDENCE: Level III, therapeutic study.