Spinner, Robert J.

BACKGROUND Intraneural perineuriomas (INPs) are rare benign peripheral nerve sheath tumors with characteristic clinical and MRI features. Their 18 F-fluorodeoxyglucose (FDG) positron emission tomography (PET) appearance has not been characterized in a patient series. The authors evaluated FDG uptake patterns in INP. OBSERVATIONS The authors retrospectively reviewed that data of patients with confirmed INP who had MRI and FDG PET studies that included the affected nerve. Eight patients were included (5 male and 3 female; mean age 30.8 years, range 16–61 years). All lesions showed mildly increased FDG uptake relative to the contralateral nerve (lesion maximum standardized uptake value [SUVmax]: mean 1.5, median 1.2, range 1.1–3.5; contralateral nerve SUVmax: mean 0.9, median 0.9, range 0.8–1.0) and skeletal muscle background (SUVmean: mean 0.8, range 0.5–0.9). Six patients had denervation edema and/or fatty atrophy, without appreciably increased FDG uptake in the affected musculature. No additional abnormal hypermetabolic foci were identified. LESSONS INPs generally demonstrate low-level FDG uptake. PET is best regarded as a complementary test when already available or when metabolic characterization may refine the differential diagnosis; unexpectedly high uptake should prompt reconsideration of the diagnosis or additional evaluation. https://thejns.org/doi/10.3171/CASE26698

OBJECTIVE Ganglioneuromas (GNs) are rare benign tumors arising from sympathetic neural crest derivatives, with limited large-scale data guiding management. The objective of this study was to characterize the clinical presentation, imaging features, surgical management, and long-term outcomes of patients with GN treated at a single institution over a 30-year period. METHODS The authors conducted a retrospective review of all patients diagnosed with GN between 1995 and 2025 at a single institution. Clinical data, imaging characteristics, operative details, perioperative complications, and long-term outcomes were abstracted. RESULTS A total of 101 patients (62.3% female, mean age 26.9 ± 15.9 years) were identified. Tumors most commonly arose in the retroperitoneum (n = 46, 45.5%), thoracic paraspinal/mediastinal region (n = 33, 32.7%), presacral space (n = 18, 17.8%), and cervical region (n = 4, 4%). The mean tumor dimensions on MRI were 8.5 ± 3.8 × 6.6 ± 3.2 × 5.8 ± 3.7 cm. Most lesions (72%) were incidental findings. Seventy patients underwent 72 surgeries, of which 69.4% had preoperative biopsy confirmation. Gross-total resection (GTR) was achieved in 73.6% of cases (53/72) and subtotal resection (STR) was performed in 26.4% (19/72). Short-term postoperative complications occurred in 43.1% of cases, most commonly neurological deficits (22.2%). The mean hospital length of stay was 4.6 ± 3.7 days. At the final follow-up (mean duration 33.8 ± 42.6 months), 46.5% of patients were stable, 42.3% had improved, and 11.3% had worsened from baseline. Two patients experienced recurrence (2.9%, 2/70). No malignant transformations were observed. Thirty-one patients were managed with observation (mean age 32.3 ± 17.7 years; mean follow-up duration 90.9 ± 151 months). Observation was chosen primarily due to proximity to major vascular or neural structures (74.2%). No patient in the observation group developed new symptoms, and 2 tumors exhibited minimal interval growth (0.08–0.17 cm/year). CONCLUSIONS GNs demonstrate indolent behavior, low recurrence rates, and no observed malignant transformation in this large cohort. GTR is achievable in most cases, but STR provides excellent long-term control when required to avoid morbidity. Observation is safe for asymptomatic tumors, particularly when adjacent to critical structures, with no growth observed on long-term follow-up, except for minimal growth in few cases. These findings support an individualized, risk-based approach to management.

BACKGROUND Malignant peripheral nerve sheath tumors (MPNSTs) are malignant tumors that rarely demonstrate heterologous differentiation from angiosarcomatous components. These lesions can be hard to accurately diagnose. OBSERVATIONS A 25-year-old man with neurofibromatosis type 1 and a history of a left lumbar subcutaneous MPNST developed a lung metastasis of only the angiosarcoma component of the MPNST. Prior to H3K27me3 staining of the lung mass, there was no association of the angiosarcoma with the MPNST. Reinterpretation of the lumbar subcutaneous MPNST led to the identification of a previously unrecognized angiosarcomatous portion in that tumor as well. LESSONS This case highlights the importance of using H327me3 staining for accurate diagnosis of biopsies only capturing the heterologous components of MPNST. https://thejns.org/doi/10.3171/CASE251012

BACKGROUND Cystic adventitial disease (CAD) and intraneural ganglion cysts (IGCs) are rare mucinous lesions typically linked to an articular origin via macroscopic conduits. While secondary propagation between vascular and neural systems may occur through shared fascial sheaths, a direct microvascular route has not been previously described. OBSERVATIONS A 60-year-old man presented with progressive left tibial neuropathy. High-resolution 7T MRI and surgery revealed a large popliteal CAD lesion connecting to the knee joint via the middle genicular artery, alongside a secondary tibial IGC lacking an independent articular nerve connection. Findings demonstrated that high-pressure CAD mucin tracked along a small connecting vascular branch, creating a novel microvascular arterio-neural pathway to infiltrate the tibial nerve. Targeted articular branch disconnection and cyst decompression yielded significant clinical improvement, with no recurrence on 7-month follow-up 7T MRI. LESSONS This case expands the unifying articular theory, demonstrating that synovial fluid propagation can exploit a microvascular arterio-neural pathway rather than strictly macroscopic fascial planes. High-resolution 7T MRI is essential for visualizing these subtle connections. Successful management requires meticulous identification and disconnection of the primary joint connection to prevent recurrence. https://thejns.org/doi/10.3171/CASE26411

OBJECTIVE Schwannomas in the tibial, plantar, or medial calcaneal nerves around the ankle can mimic symptoms of tarsal tunnel syndrome. Outcomes after resection of schwannomas from these nerves have mainly been reported in case reports. The objectives of this study were to investigate the presentation and results for resection of schwannomas around the tarsal tunnel in a large case series and systematically review the currently available literature. METHODS Data from 40 patients (27 sporadic and 13 schwannomatosis cases) treated at 2 centers were retrospectively analyzed for preoperative type and duration of symptoms, schwannoma size at presentation, and outcome after resection. The following different locations around the ankle were compared: proximal to the tarsal tunnel (PTT), at the tarsal tunnel (ATT), and distal to the tarsal tunnel (DTT). The severity of symptoms was categorized in increasing order for pain only on touch, during load-bearing activities, and symptoms also at rest. Surgical outcome was assessed based on pain relief and occurrence of complications. The systematic literature review was performed using a PubMed and Embase search. RESULTS All but 1 patient presented with pain, local at the ankle, or neuropathic pain during weight-bearing activities (13/40, 32.5%). More than half of the patients also experienced symptoms at rest (52.5%). In 14 cases, the schwannoma was located PTT, in 17 cases ATT, and in 9 cases DTT in the plantar nerves. There were no significant differences in size and symptom duration at presentation for the different locations. Tumor size did not correlate with symptom severity. Outcomes after resection were excellent, with complete pain relief in all but 1 patient (97.0%). Complications included wound infection (5%) and temporary decreased sensation on the heel (7.5%). A review of 44 previously reported cases also frequently showed complete pain relief after resection. CONCLUSIONS The results of this study show that schwannomas around the tarsal tunnel often present with severe pain symptoms, even if the lesion is still relatively small. Resection frequently results in excellent pain relief. During surgery, it may not be necessary to open the entire length of the tarsal tunnel, thereby limiting the size of the incision, especially in schwannomas located proximally or distally to the tarsal tunnel.

ABSTRACT The term “clinical anatomy” is widely used in education and research, yet its conceptual boundaries continue to be interpreted in various ways. Prior consensus‐based efforts have emphasized integration, collaboration, and clinical relevance as central features of the field and have provided an important foundation for interdisciplinary engagement. At the same time, ongoing changes in academic structure, medical education, and interdisciplinary biomedical science raise important questions regarding how clinical anatomy can sustain its scientific identity and long‐term relevance. Building upon prior discussions, this article argues that the continued maturation of clinical anatomy depends on the integration of conceptual frameworks with the sustained production of rigorous, reproducible, and clinically meaningful scholarly contributions. Historical and contemporary examples alike demonstrate that the influence of clinical anatomy has been shaped through contributions that directly advanced clinical science and practice. Accordingly, continued emphasis on methodological rigor, reproducibility, clinically meaningful contribution, and educational accountability may be essential to the field's future development and relevance.