Okuno, Scott H.

BACKGROUND Adamantinomatous craniopharyngiomas (ACPs) are slow-growing, cystic, highly morbid central nervous system tumors located adjacent to vital structures including the pituitary, hypothalamus, and optic chiasm. Tumor recurrence is common. Treatment relies on resection with or without adjuvant radiation and is highly individualized. Targeted chemotherapies have not been routinely used in the treatment of ACPs. OBSERVATIONS The authors present the case of an adult patient with recurrent ACP that was clinically and radiologically stabilized with a combination of bevacizumab and tocilizumab every 3 weeks. LESSONS The combination of tocilizumab and bevacizumab could be an effective therapy for shrinkage of the cystic and solid components of ACP, sparing patients from further neurological damage from the tumor, additional surgery, or radiation. The patient’s positive response to tocilizumab and bevacizumab supports the growing literature that interleukin-6 and vascular endothelial growth factor are important for ACP pathogenesis. The patient’s response supports prior research, suggesting that systemic chemotherapy can be effectively delivered to this rare brain tumor. https://thejns.org/doi/10.3171/CASE24410

Background: Follicular dendritic cell sarcoma (FDCS) is a rare low- to intermediate-grade sarcoma, typically presenting as a slowly growing, painless mass composed of spindle-shaped cells in a whorled pattern. First described in 1986, FDCS has since been identified in several hundred cases. FDCS originates from mesenchymal dendritic cells and is distinct from other histiocytic neoplasms. Its management aligns more with soft tissue sarcomas. Epidemiologically, FDCS is exceedingly rare, constituting less than 0.4% of soft tissue sarcomas. Methods: With IRB approval, we identified patients with biopsy-proven FDCS treated at Mayo Clinic. Chart review extracted clinical characteristics, laboratory testing, treatment data, and clinical outcomes, compiled into Excel. Data analysis was performed through RStudios. Descriptive statistics of patient characteristics, such as gender and stage of disease, were summarized in tables. We compared overall survival (OS) through Kaplan Meier curves, stratifying patients into cohorts based on topics of interest, such as differences in survival in nodal vs. extranodal disease or differences in survival among different chemotherapy regimens. Results: Forty patients met the inclusion criteria, of biopsy proved FCDS. Median age at diagnosis was 57.7 years (SD 14). Men comprised 45% of patients. Locations of malignancy were abdomen and pelvis (32.5%), thoracic and pulmonary regions (32.5%), lymph nodes and neck (20.0%), musculoskeletal (2.5%), and other locations (12.5%). Primary therapies included surgical resection (42.5%), systemic chemotherapy (32.5%), no treatment (10.0%), radiation (2.5%), with data missing for 12.5% of cases. Concurrent or preceding Castleman's Disease was seen in 7.5% (3/40) of patients; one case preceded FCDS, and two were concurrent. Of these patients with Castleman's Disease, one was resected and the other two were not. Two cases were unicentric, and one was multicentric. First-line systemic chemotherapy was most often gemcitabine and docetaxel, with 9/40 patients receiving this regimen. Ifosfamide and doxorubicin were utilized in 3/40 patients. 2/4 patients had received doxorubicin alone. 2/4 patients had received CHOP. The response rate for patients with gemcitabine and docetaxel was complete response for 2/9 (22%) patients, partial response for 2/9 (22%), stable disease for 2/9 (22%), progressive disease for 1/9 (11%), and missing for 2/9 (22%), giving an overall response rate of 67%. For ifosfamide and doxorubicin, one patient had partial response (33%), another had stable disease (33%), and the last patient's data was missing (33%), adding up to a 66% overall response rate. For CHOP, one patient had progressive disease, and the other had partial response. For doxorubicin, both patients had stable disease. At a median follow-up of 29.5 months (IQR 9.2-75.2 months), the median OS was 160.68 months for the group with both nodal and extranodal disease versus 39.95 months for the extranodal disease-only group. The median OS of the nodal disease alone was not reached, with an estimated 2-year OS of 75%. To evaluate the impact of various primary therapies on outcomes in patients with advanced disease, we conducted a survival analysis by therapy used (no treatment, radiation, surgical resection, and systemic chemotherapy). Patients receiving no treatment had a median survival time of 28.9 months, while those treated with radiation had a median survival time of 19.3 months. Patients undergoing surgical resection had an undetermined median survival time, but notably, 80% were alive at the end of the time period analyzed in this study with a median follow-up time of 60.7 months. Those receiving systemic chemotherapy had a median survival time of 30.7 months. Conclusions: This project is one of the largest known single-center studies dedicated to FDCS. We show that the incidence of preceding or concurrent Castleman's Disease is relatively low. Gemcitabine and docetaxel was the most utilized chemotherapy regimen, but there weren't enough data to conclude if this regimen had a better response rate compared to others. Surgical resection of advanced disease is associated with superior outcomes. When systemic therapy is needed, the median survival was lower.

Background: Myxoid liposarcoma predominantly affects young and middle-aged individuals, and little is known regarding treatment tolerability and outcomes in older patients. This study aims to better understand this older patient population. Methods: This single institution retrospective study included patients aged 70 years and older with localized (non-metastatic) myxoid liposarcoma. Results: Sixteen patients were included. The median age was 75 years, and 9 (56%) were female. Fourteen (88%) were extremity tumors and two (12%) were trunk. The median tumor size was 10.4 cm (range, 3.6 to 28 cm). Five (31%) tumors had a round cell component. All patients had surgery. Fourteen (88%) had perioperative radiation, and three (19%) had perioperative chemotherapy. One patient had postoperative infection, and one patient had neutropenic fever from preoperative chemotherapy. The median follow up from surgery was 6.3 years. Eight (50%) patients died from MLPS. The median relapse-free survival and overall survival were 34 months and 75 months, respectively. Conclusions: Most older patients with localized MLPS received perioperative radiation therapy with surgery, and few serious toxicities were reported. Even with treatment, half of the patients relapsed.

Background: Synovial sarcoma is rare and may present as a small, slow-growing mass. These tumors are often mistaken as benign and are therefore prone to unplanned and/or non-oncologic excision. We sought to identify the rate of unplanned excision of synovial sarcoma and risk factors for recurrence and survival among this cohort. Methods: The medical records of 246 patients evaluated at a single institution for synovial sarcoma between 1997 and 2022 were retrospectively reviewed. Of these, 87 (35%) underwent unplanned, non-oncologic excision. The mean age of the cohort was 49 years. Primary tumors were located in the extremity (n = 63), abdomen (n = 6), thorax (n = 7), head/neck (n = 8), and paraspinal region (n = 3). The median maximum pre-treatment dimension of the primary tumor was 4.8 cm (IQR 7–2.4). Seventy-seven (86%) patients underwent re-excision of the tumor bed, 39 (45%) received chemotherapy, and 63 (72%) received radiation therapy. Results: Among patients who underwent unplanned excision, local recurrence-free survival (LRFS) was 98% at 1 year and 82% at 5 years. Metastasis-free survival (MFS) was 91% at 1 year and 72% at 5 years. Disease-specific survival (DSS) was 98% at 1 year and 72% at 5 years. When adjusting for tumor size, tumors which underwent unplanned excision did not have worse recurrence or survival compared to those which had planned excision (p > 0.10). Size > 5 cm, monophasic subtype, and axial location were associated with increased risk of disease recurrence. Forty-six patients had residual tumor following re-excision, which was associated with worse MFS (HR 8.17, 95% CI [1.89, 35.2], p < 0.01) and DSS (HR 7.66, 95% CI [1.76, 33.4], p < 0.01). Patients who received radiotherapy had improved MFS (HR 6.4, 95% CI [1.42, 29.0], p = 0.02) and DSS (HR 5.86, 95% CI [1.27, 26.9], p = 0.02). Conclusions: One-third of patients presenting with synovial sarcoma were diagnosed after unplanned, non-oncologic excision. Patients with large, axial tumors had worse survival. Approximately half of patients who underwent unplanned excision had no residual tumor after pre-operative radiation. The use of radiation was associated with decreased rates of recurrence and improved disease-specific survival. Our results suggest that margin-negative re-resection and radiotherapy should be considered when feasible following unplanned excision of synovial sarcoma.

Background: Liposarcoma, one of the most prevalent sarcoma histologies, is recognized for its tendency for extra-pulmonary metastases. While oligometastatic cardiac disease is rarely reported, it poses a unique challenge as oligometastatic sarcomas are often managed with surgical resection. Case Report: We present a case of a 62-year-old man diagnosed with an oligometastatic myxoid liposarcoma (MLPS) to the heart 19 years after the primary tumor resection from the lower limb. The metastatic mass, situated in the pericardium adjacent and infiltrating the left ventricle, was not managed surgically but with a combination of chemotherapy and radiotherapy. The patient’s disease remains stable to date, for more than 10 years. Literature Review: We conducted a review of the literature to determine the preferred management approach for solitary cardiac metastases of sarcomas. We also conducted an in-depth analysis focusing on reported cases of MLPS metastasizing to the heart, aiming to extract pertinent data regarding the patient characteristics and the corresponding management strategies. Conclusions: Although clinical diagnoses of solitary or oligometastatic cardiac metastases from sarcomas are infrequent, this case underscores the significance of aggressive management employing chemotherapy and radiotherapy for chemosensitive and radiosensitive sarcomas, especially when surgical removal is high-risk. Furthermore, it challenges the notion that surgery is the exclusive therapeutic option leading to long-term clinical benefit in patients with recurrent sarcomas.

11521 Background: Osteosarcomas (OS) comprise the majority of new primary bone tumors in the US and affect a bimodal distribution of young adults (2nd-3rd decades) and older adults >65 yrs. Most large collaborative studies demonstrating the efficacy of HDMTX-containing chemotherapy regimens in OS limited enrollment to patients <40 yrs. Our study aims to fill the gap of reported clinical outcomes in adult OS patients ≥ 40 yrs by describing the feasibility and tolerability of HDMTX in these patients at Mayo Clinic. Methods: We conducted a retrospective chart review of patients ≥18 yrs with OS seen at our institution between 1/1/1980-9/30/2019 and who received ≥1 dose of HDMTX (12 g/m2, max 20 g). Extraosseous OS were excluded. Survival analyses were run for both the entire study population and the subset of patients age ≥40. Patient demographics, disease characteristics, and clinical outcomes were collected. The primary outcome evaluated was 5-year overall survival (5-yr OS). Results: We identified 94 patients whose demographic data are summarized (Table). Twenty-three of 94 (24%) were ≥40 yrs. Both the median number of HDMTX doses received and number of patients who received ≥50% recommended doses were significantly less among patients ≥40 yrs. However, HDMTX-related AKI and median number of hospital days did not differ significantly between the age groups. Among all patients, 5-yr OS was significantly improved (p=0.0025) at 45% (95% CI 35%-58%) for those who received ≥50% doses HDMTX compared to 5-yr OS of 25% (95% CI 12%-53%) for those who did not. Among patients ≥40 yrs, 5-yr OS was significantly improved (p=0.017) at 86% (95% CI 63%-100%) for those who received ≥50% doses HDMTX compared to 5-yr OS of 31% (95% CI 14%-68%) for those who did not. Conclusions: In our cohort, 5-yr OS was superior in those patients who received at least 50% of the planned doses of HDMTX. Older adults were significantly less likely to receive the majority of planned doses, which may be due to clinician bias regarding anticipated toxicity. However, we show that common HDMTX-associated toxicities did not vary significantly by age. If feasible, we recommend referring older patients with osteosarcoma to centers equipped to handle the staffing and supportive care needs of HDMTX administration. [Table: see text]

Abstract Background Radiation‐associated soft tissue sarcomas (RA‐STS) are rare complications of patients receiving radiation therapy (RT) and are generally associated with a poor prognosis. Most of the literature surrounding RA‐STS of the chest is centered on angiosarcoma. Therefore, we aim to document the management and outcome of patients with non‐angiosarcoma RA‐STS of the chest. Methods We reviewed 17 patients (all female, median age 65 years) diagnosed with RA‐STS. The most common primary malignancy was breast carcinoma ( n = 15), with a median RT dose of 57.9 Gy. All patients underwent surgical resection; five patients (29%) received radiotherapy; and five patients (29%) received peri‐operative chemotherapy. Results The 5‐year local recurrence and metastatic‐free survival were 61% and 60%, while the 5‐year disease‐specific survival was 53%. Local recurrence was associated with death due to disease (HR 9.06, p = 0.01). Complications occurred in nine of patients, most commonly due to a wound complication ( n = 7). At the most recent follow‐up, the median Musculoskeletal Tumor Society Score was 63%. Conclusion RA‐STS involving the chest wall are aggressive tumors with a high risk of local relapse and death due to disease. Local recurrence was associated with death due to disease; as such, we recommend aggressive surgical management with evaluation for adjuvant therapies.

e23554 Background: Follicular dendritic cell sarcoma (FDCS) is a low-grade neoplasm arising from follicular dendritic cells. Its diagnosis is challenging due to its extreme rarity, and the optimal management remains unknown. Methods: We conducted a retrospective study of FDCS patients (pts) seen at Mayo Clinic, MN since 2018. Time to event analyses were done from the time of diagnosis. Results: Ten pts with FDCS were identified (Table). The median age was 60 years (range, 38-76) and 5 were males. Abdominal pain was the most common presenting symptom (30%) followed by constitutional symptoms, shortness of breath, and vision change. In 3 pts, the diagnosis was incidental. The 2 most common primary locations were abdomen/pelvis (50%) and mediastinum (30%). Six pts (60%) presented with advanced disease and 3 (30%) had Castleman’s disease. Most (60%) had advanced disease. Six pts had Epstein-Barr virus in situ hybridization and all tested negative. Seven pts had next generation sequencing and 5 (83%) had genetic alterations detected with CDKN2A/B alterations being most frequent (3 pts, all with advanced disease). The median follow up was 4.3 years (range, 0.2-13.3). In the 4 patients with localized disease, 3 underwent complete surgical excision resulting in complete remissions (CRs). The one who received radiation had a partial remission (PR). The median time to progression after 1st line treatment was 4 months (all with advanced disease). All 3 pts who died had advanced disease and 2 had CDKN2A/B alterations. Conclusions: In FDCS, localized diseases managed by surgical excision with or without radiation can achieve long term remissions. Advanced diseases generally do not respond to multimodality therapy including immunotherapy but can have disease stabilization with variable survival. CDKN2A/B mutations were common and potentially associated with a worse outcome. Better understanding of the impact of the FDCS mutational landscape on prognosis may provide novel approaches to therapy. [Table: see text]