Undifferentiated round cell sarcoma with CRTC1::SS18 fusion: Expanding clinicopathologic features of a rare translocation sarcoma with prominent desmoplastic stroma.

Undifferentiated round cell sarcomas (URCS) represent a diverse group of tumors, including conventional Ewing sarcoma, round cell sarcoma with EWSR1/FUS-non-ETS fusions, CIC-rearranged sarcoma, and sarcoma with BCOR alterations. Since 2018, three cases of URCS with a novel CRTC1::SS18 gene fusion have been reported in the literature. Herein, we report three additional cases of CRTC1::SS18 sarcoma, thereby doubling the number of described cases and expanding the clinicopathologic features of this rare translocation sarcoma. Together with the previously reported cases, we show that the male-to-female ratio is 1:2 with a median age of 34 years (range: 12 to 42 years). Tumors occurred primarily in intramuscular locations involving the lower extremity. Histologically, all tumors contained uniform round to epithelioid cells with a moderate amount of eosinophilic cytoplasm growing in sheets and nests with prominent desmoplastic stroma reminiscent of desmoplastic small round cell tumor (DSRCT). Immunohistochemical results were non-specific, demonstrating variable expression of CD99 (patchy), ALK, GATA3, and cyclin D1. RNA sequencing revealed CRTC1::SS18 gene fusions in all cases, involving exon 1-2 of CRTC1 (the 5' partner gene) on chromosome 19 and either exon 2 or exon 4 of SS18 (the 3' partner gene) on chromosome 18. The clinical course was variable. While one previously reported case demonstrated aggressive behavior with fatal outcome, two others had a relatively indolent course with gradual growth for 6-7 years prior to resection. Two cases developed metastatic disease, including one case with bilateral lung metastasis and one with locoregional spread to a lymph node. By analyzing the clinicopathologic features, we aim to improve recognition of this rare translocation sarcoma to better understand its biologic potential, optimize patient management, and expand the current classification of URCS.

Symptomatic Neuroma Development following En Bloc Resection of Skeletal and Soft-Tissue Tumors: A Retrospective Analysis of 331 Cases.

BACKGROUND: Although symptomatic neuroma formation has been described in other patient populations, these data have not been studied in patients undergoing resection of musculoskeletal tumors. This study aimed to characterize the incidence and risk factors of symptomatic neuroma formation following en bloc resection in this population. METHODS: The authors retrospectively reviewed adults undergoing en bloc resections for musculoskeletal tumors at a high-volume sarcoma center from 2014 to 2019. The authors included en bloc resections for an oncologic indication and excluded non-en bloc resections, primary amputations, and patients with insufficient follow-up. Data are provided as descriptive statistics, and multivariable regression modeling was performed. RESULTS: The authors included 231 patients undergoing 331 en bloc resections (female, 46%; mean age, 52 years). Nerve transection was documented in 87 resections (26%). There were 81 symptomatic neuromas (25%) meeting criteria of Tinel sign or pain on examination and neuropathy in the distribution of suspected nerve injury. Factors associated with symptomatic neuroma formation included age 18 to 39 [adjusted OR (aOR), 3.6; 95% CI, 1.5 to 8.4; P < 0.01] and 40 to 64 (aOR, 2.2; 95% CI, 1.1 to 4.6; P = 0.04), multiple resections (aOR, 3.2; 95% CI, 1.7 to 5.9; P < 0.001), preoperative neuromodulator requirement (aOR, 2.7; 95% CI, 1.2 to 6.0; P = 0.01), and resection of fascia or muscle (aOR, 0.5; 95% CI, 0.3 to 1.0; P = 0.045). CONCLUSION: The authors' results highlight the importance of adequate preoperative optimization of pain control and intraoperative prophylaxis for neuroma prevention following en bloc resection of tumors, particularly for younger patients with a recurrent tumor burden. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.

Metastatic sarcomatoid carcinoma to bone.

BACKGROUND AND OBJECTIVES: Distinguishing sarcomatoid carcinoma from primary sarcoma is clinically important. We sought to characterize metastatic sarcomatoid bone disease and its management. METHODS: We analyzed the characteristics of all cases of sarcomatoid carcinoma to bone at a single institution from 2001 to 2021, excluding patients with nonosseous metastases. Survival was evaluated using the Kaplan-Meier method. RESULTS: We identified 15 cases of metastatic sarcomatoid carcinoma to bone. In seven cases the primary cancer was unknown at presentation. Renal cell carcinoma was suspected or confirmed in nine cases. Nine patients presented with pathologic fracture and two with concomitant visceral metastases. All patients underwent image-guided core needle or open biopsy. Ten required surgery for discrete osseous metastases; in four cases definitive surgery was delayed (median delay, 19 days) due to inability to rule out sarcoma with frozen section. No patients required reoperation or had construct failure. Thirteen died of disease; median survival was 17.5 months (interquartile range, 6.2-25.1). CONCLUSIONS: Metastatic sarcomatoid carcinoma is a clinically challenging entity. Multidisciplinary input and communication are key to identifying the primary carcinoma, locating osseous metastases, and defining an operative fixation that will survive the remainder of the patient's life.

The Role of Denosumab in the Treatment of Primary Tumors of Bone.

Many hand surgeons treat benign bone tumors without referral to orthopedic oncologists. However, there have been considerable advances in medical therapy for some of these tumors, with which hand surgeons may not be as familiar. This review focuses on the mechanism and uses of denosumab in the treatment of benign tumors of bone. Although the hand surgeon may not be directly prescribing this therapy, they are often the only physician treating the patient for these conditions. As such, awareness regarding the use of this therapy in reducing pain, decreasing tumor volume, and treatment of potential lung metastases is critical to those taking on these cases without the support of an orthopedic oncologist. This article aims to familiarize hand surgeons with denosumab to help promote knowledge of this therapeutic option and the potential role of this medication in the treatment of primary bone tumors in the hand.

Indications and outcomes of palliative major amputation in patients with metastatic cancer.

BACKGROUND: Patients with stage IV cancer often experience diminished quality of life and pain. Although palliative amputation (PA) can reduce pain, it is infrequently performed because of the morbidity associated with amputation and the limited life expectancy in this population. Here, we describe the indications for PA in patients with stage IV carcinoma or sarcoma and discuss their clinical courses and outcomes. We hypothesized that PA would be associated with reduced pain and improved quality of life in these patients. METHODS: We retrospectively reviewed medical records of all patients who underwent major amputation (proximal to the ankle or wrist) for metastatic sarcoma or carcinoma from January 1995 to April 2021. We excluded patients who underwent amputation for indications other than palliation. Cox proportional hazards regression analysis was used to determine factors associated with survival after PA. RESULTS: Twenty-six patients underwent PA (11 for carcinoma, 15 for sarcoma). The most common indications for PA were pain (all patients) and fungating tumor (16 patients). PA was the initial surgery in 7 patients. Forequarter amputations were the most common procedure (6 patients). All patients reported reduced pain after PA, with the mean (±standard deviation) visual analog pain score (on a 10-point scale) decreasing from 5.7 ± 2.9 preoperatively to 0.43 ± 1.3 postoperatively (p < 0.001). The mean preoperative ECOG score was 1.9 ± 0.2 compared with 1.3 ± 0.1 postoperatively (p < 0.001). Fourteen patients were fitted for prostheses (6 upper extremity, 8 lower extremity). Two patients had local recurrence, both within 6 months after PA. The mean survival time after PA was 13 ± 12 months, and mean follow-up was 28 ± 29 months. Mean survival time after PA was not significantly different between patients with sarcoma (11 ± 11 months) versus carcinoma (15 ± 14 months) (p = 0.51). Adjuvant chemotherapy was positively associated with survival; no other factors were associated with survival. CONCLUSIONS: PA was associated with significantly reduced pain in all patients with stage IV cancer. PA should be considered for those with intractable pain, fungating tumors, or symptoms that diminish quality of life. LEVEL OF EVIDENCE: Level III.

Tumors of the Hand and the Wrist.

Most tumors of the hand and the wrist are benign; however, malignant conditions can mimic benign tumors and must be worked up accordingly. Advanced imaging should be followed by biopsy before definitive treatment of tumors of unknown diagnosis. The most common soft-tissue masses in the hand and the wrist are ganglion cysts, whereas the most common bone tumors are enchondromas.

Sarcoma of the Lower Limb: Reconstructive Surgeon's Perspective.

Management of sarcomas in the lower extremities have evolved from amputations to limb-preserving surgeries with evidence to support that they have equal overall survival, albeit with better functional outcome. The challenge of reconstruction lies in providing a durable, functional, and aesthetically pleasing limb. However, limb-preserving intention should not delay interventions that provide a survival benefit such as chemotherapy and radiotherapy. The advent of radiotherapy and chemotherapy also has implications on wound healing and should be considered during the reconstructive process. This article reviews the methodical approach, reconstructive strategies, and considerations for the reconstructive surgeon with respect to the lower extremity after sarcoma excision.

Nerve Tumors of the Upper Extremity.

Nerve sheath tumors of the upper extremity are among the common neoplastic pathologies encountered by hand surgeons. A majority of these tumors are benign schwannomas or neurofibromas and may be associated with neurofibromatosis. Clinical signs of malignant transformation include new onset of pain and rapid growth. Imaging characteristics, such as standardized uptake value greater than 4.0 on PET scan, may aid in the diagnosis of a malignant tumor. Surgical excision, often with intrafascicular dissection with nerve preservation, is recommended treatment of benign lesions. Wide surgical excision is recommended for malignant lesions.

Use of the S3 Corridor for Iliosacral Fixation in a Dysmorphic Sacrum: A Case Report.

CASE: The S1 and S2 corridors are the typical osseous pathways for iliosacral screw fixation of posterior pelvic ring fractures. In dysmorphic sacra, the S1 screw trajectory is often different from that in normal sacra. We present a case of iliosacral screw placement in the third sacral segment for fixation of a complex lateral compression type-3 pelvic fracture in a patient with a dysmorphic sacrum. CONCLUSION: In patients with dysmorphic sacra and unstable posterior pelvic ring fractures or dislocations, the S3 corridor may be a feasible osseous fixation pathway that can be used in a manner equivalent to the S2 corridor in a normal sacrum.

Intraoperative Neuromonitoring in Pediatric and Adult Spine Deformity Surgery.

STUDY DESIGN: Review of techniques and description of institutional clinical experience. OBJECTIVE: To provide a historical review and description of key neuromonitoring concepts, focusing on neurogenic motor-evoked potentials and descending neurogenic evoked potentials, and to review the authors' experience with neuromonitoring techniques in children and adults undergoing spinal deformity surgery. SUMMARY OF BACKGROUND DATA: The original form of neuromonitoring, the Stagnara wake-up test, remains the "gold standard" for detecting true neurological deficits. Multiple newer modalities involving cortical and muscular monitoring, such as somatosensory evoked potentials and motor evoked potentials, have been developed and are widely used. Descending and neurogenic evoked potentials are becoming more common for neuromonitoring in patients undergoing spinal deformity surgery. METHODS: A PubMed search for literature related to "neuromonitoring" was performed, and recent, as well as historical, articles were reviewed. Clinical experience regarding the use of neuromonitoring in adult and pediatric spinal deformity surgery was obtained from institutional experts. RESULTS: Although not regularly used, the Stagnara wake-up test remains the gold standard for detecting neurological injury. Somatosensory evoked potentials measure signals transmitted from the periphery to the cortex and have historically been widely used but are limited by delay, poor localization, and the inability to detect damage to motor tracts. Motor evoked potentials continue to be used widely and measure muscular activity after cortical stimulation, but they are difficult to interpret in patients with underlying motor disorders and cannot be continuously monitored. Newer techniques such as descending neurogenic evoked potentials and neurogenic motor evoked potentials monitoring are used at some high-volume centers. CONCLUSIONS: Familiarity with the history of neuromonitoring in spinal deformity surgery and an understanding of the physiological systems used for neuromonitoring provide a framework from which spine surgeons can select appropriate monitoring for their patients.

Pelvic Fixation in Adult and Pediatric Spine Surgery: Historical Perspective, Indications, and Techniques: AAOS Exhibit Selection.

Achieving solid osseous fusion across the lumbosacral junction has historically been, and continues to be, a challenge in spine surgery. Robust pelvic fixation plays an integral role in achieving this goal. The goals of this review are to describe the history of and indications for spinopelvic fixation, examine conventional spinopelvic fixation techniques, and review the newer S2-alar-iliac technique and its outcomes in adult and pediatric patients with spinal deformity. Since the introduction of Harrington rods in the 1960s, spinal instrumentation has evolved substantially. Indications for spinopelvic fixation as a means to achieve lumbosacral arthrodesis include a long arthrodesis (five or more vertebral levels) or use of three-column osteotomies in the lower thoracic or lumbar spine, surgical treatment of high-grade spondylolisthesis, and correction of lumbar deformity and pelvic obliquity. A variety of techniques have been described over the years, including Galveston iliac rods, Jackson intrasacral rods, the Kostuik transiliac bar, iliac screws, and S2-alar-iliac screws. Modern iliac screws and S2-alar-iliac screws are associated with relatively low rates of pseudarthrosis. S2-alar-iliac screws have the advantages of less implant prominence and inline placement with proximal spinal anchors. Collectively, these techniques provide powerful methods for obtaining control of the pelvis in facilitating lumbosacral arthrodesis.

rhBMP use in cervical spine surgery: associated factors and in-hospital complications.

BACKGROUND: Widespread use of recombinant human bone morphogenetic protein (rhBMP) in cervical spine surgery has continued despite the U.S. Food and Drug Administration's 2008 notification regarding its adverse effects. Our study goals were to analyze how patient, surgical, and institutional factors influenced rhBMP use in cervical spinal fusion surgery and to examine the cervical-spine-specific in-hospital complications associated with rhBMP use. METHODS: The Nationwide Inpatient Sample database was used to identify 1,064,372 patients eighteen years or older who had undergone cervical spinal fusion surgery from 2003 through 2010. Of these patients, 84,726 (7.96%) received rhBMP. Multivariate logistic regression models were used to analyze patient, surgical, and institutional factors associated with rhBMP use, and the relationship between rhBMP use and the development of in-hospital complications. RESULTS: On multivariate analysis, patient age and sex, insurance type, surgical approach, use of autograft bone, and hospital teaching status, size, and region were significant predictors of rhBMP use. Use of rhBMP was a significant predictor of complications on univariate analysis and on multivariate analysis adjusted for patient age and sex, Charlson comorbidity score, insurance status, surgical approach, autograft bone use, and hospital teaching status, size, and region. Use of rhBMP was significantly associated with the development of dysphagia (prevalence, 2.0%; adjusted odds ratio [OR], 1.53), dysphonia (prevalence, 0.28%; adjusted OR, 1.48), hematoma/seroma formation (prevalence, 0.7%; adjusted OR, 1.24), and neurological complications (prevalence, 0.84%; adjusted OR, 2.0). These complications were most commonly found after anterior cervical fusion surgery. Wound infections and neurological complications were most commonly found after posterior cervical fusion surgery. Dysphagia was most commonly found after circumferential fusion surgery. CONCLUSIONS: Indications for rhBMP use for cervical spinal fusion are multifactorial. Its use is associated with a significantly higher likelihood of cervical-spine-specific complications.

Role of fracture and repair type on pain and opioid use after hip fracture in the elderly.

BACKGROUND AND PURPOSE: Pain after hip fracture repair is related to worse functional outcomes and higher fracture care costs than that for patients with no or less pain. However, to our knowledge, few studies have examined the roles of hip fracture type or surgical procedure as factors influencing postoperative pain or opioid analgesic requirements. Our goal was to determine whether the type of hip fracture or hip fracture repair affects postoperative pain or opioid analgesic requirements in the elderly patient. METHODS: We conducted a retrospective review of 231 patients ≥65 years old admitted to a hip fracture center for surgical repair. Fracture patterns were classified into femoral neck (FN) versus intertrochanteric (IT), stable versus unstable, and type of surgical repair. Demographic and intraoperative variables, postoperative pain scores, and opioid analgesic use data were collected and analyzed according to the type of hip fracture and type of surgical repair. RESULTS: There were no differences in postoperative pain when comparing FN versus IT fractures, stable versus unstable fractures, or type of surgical repair. Patients with FN fractures had higher analgesic requirements on postoperative days 1, 2, and 3. There was no difference in postoperative analgesic requirements among patients with stable versus unstable fractures or type of surgical repair. Otherwise, there were no differences in postoperative pain or opioid analgesic use based on the surgical repair or fracture type. Overall, patients with hip fracture experienced low levels of pain.

Chondrosarcoma of the spine: a series of 16 cases and a review of the literature.

Only a few major studies of chondrosarcoma of the mobile spine have been reported. These studies have shown that spinal chondrosarcomas require complete surgical resection and are notoriously resistant to chemotherapy and radiation. We present 16 cases of chondrosarcoma of the mobile spine diagnosed at a median age of 54.5 (range 20 - 79) years. Diagnosis and treatment studies were based on both CT scans and MRI. Fifteen of our 16 patients had low-grade (grade 1-2) chondrosarcomas. All patients were treated with surgical resection. Fourteen patients had total resection while two patients had subtotal resection. The two patients who had subtotal resection died of their disease. Five of the fourteen patients who had total resection also died. The mean interval to death was 3.6 years. This study confirms that although chondrosarcomas of the spine are low grade, they are dangerous neoplasms. Even with complete resection, they have a high rate of recurrence and metastasis.

Septic elbow in the setting of neuropathic joint as the initial presentation of a cervical syrinx.

Neuropathic arthropathy, or Charcot's joint, is a degenerative disorder resulting from abnormal sensory innervation that is associated with diabetes mellitus, tabes dorsalis, and syringomyelia. Patients may present with a painless instability of the affected joint, although a range of symptoms are seen. This article presents a case of a patient who presented with a swollen elbow, consistent with septic arthritis, and bilateral lower extremity weakness. Joint fluid cultures were positive for methicillin-resistant Staphylococcus aureus. Extensive joint destruction on radiographic imaging and a thorough neurologic examination revealing generalized weakness and upper motor neuron signs prompted magnetic resonance imaging (MRI) of the spine which revealed a cervical syrinx. Our patient was diagnosed with syringomyelia-associated neuropathic arthropathy that initially presented as a septic joint. In the setting of septic arthritis, substantial joint destruction (particularly in a patient with neurologic deficits) should prompt additional investigation, including MRI of the spine, for neurologic causes. Although surgery is generally not recommended for neuropathic arthropathy because of poor healing and high rates of complication, neuropathic arthropathy in the setting of a septic joint requires operative irrigation and debridement.