David K. Monson

Neuropathy secondary to pigmented villonodular synovitis of the hip.

Pigmented villonodular synovitis is a benign proliferative process of unknown origin that may cause extensive bone and joint destruction. Patients with this condition typically present with symptoms of mild discomfort and associated stiffness of the involved joint; however, the spectrum of presentations is broad. Although pigmented villonodular synovitis begins in, and usually is confined within, a synovium-lined joint, it may extend beyond the joint capsule and present as a soft tissue mass. Three cases of a previously unrecognized presentation of pigmented villonodular synovitis of the hip joint are presented. The authors believe these to be the first reported cases in the English language literature of pigmented villonodular synovitis of the hip seen with femoral or sciatic neuropathy.

Epithelioid sarcoma-like (pseudomyogenic) hemangioendothelioma, clinically mimicking dermatofibroma, diagnosed by skin biopsy in a 30-year-old man.

Epithelioid sarcoma‐like (pseudomyogenic) hemangioendothelioma (ESHE) represents a rare soft tissue and bone tumor that typically presents as nodule(s) in the distal extremities of young adults. The nodules traverse several tissue planes simultaneously and can involve the dermis, subcutis, skeletal muscle and bone. ESHE shares clinical and microscopic features with epithelioid sarcoma (ES), and, accordingly, is commonly misdiagnosed as ES. However, unlike ES, which has a poor prognosis, ESHE commonly follows an indolent course. Herein, we report a case of ESHE diagnosed by skin biopsy that clinically mimicked a dermatofibroma. We also provide clinical photographs of the lesions in various stages of development, representing information that has not been previously published, to our knowledge.

Anatomic Tumor Location Influences the Success of Contemporary Limb-Sparing Surgery and Radiation Among Adults With Soft Tissue Sarcomas of the Extremities

PURPOSE To examine the influence of anatomic location in the upper extremity (UE) vs. lower extremity (LE) on the presentation and outcomes of adult soft tissue sarcomas (STS). METHODS AND MATERIALS From 2001 to 2008, 118 patients underwent limb-sparing surgery (LSS) and external beam radiotherapy (RT) with curative intent for nonrecurrent extremity STS. RT was delivered preoperatively in 96 and postoperatively in 22 patients. Lesions arose in the UE in 28 and in the LE in 90 patients. Patients with UE lesions had smaller tumors (4.5 vs. 9.0 cm, p < 0.01), were more likely to undergo a prior excision (43 vs. 22%, p = 0.03), to have close or positive margins after resection (71 vs. 49%, p = 0.04), and to undergo postoperative RT (32 vs. 14%, p = 0.04). RESULTS Five-year actuarial local recurrence-free and distant metastasis-free survival rates for the entire group were 85 and 74%, with no difference observed between the UE and LE cohorts. Five-year actuarial probability of wound reoperation rates were 4 vs. 29% (p < 0.01) in the UE and LE respectively. Thigh lesions accounted for 84% of the required wound reoperations. The distribution of tumors within the anterior, medial, and posterior thigh compartments was 51%, 26%, and 23%. Subset analysis by compartment showed no difference in the probability of wound reoperation between the anterior and medial/posterior compartments (29 vs. 30%, p = 0.68). Neurolysis was performed during resection in (15%, 5%, and 67%, p < 0.01) of tumors in the anterior, medial, and posterior compartments. CONCLUSIONS Tumors in the UE and LE differ significantly with respect to size and management details. The anatomy of the UE poses technical impediments to an R0 resection. Thigh tumors are associated with higher wound reoperation rates. Tumor resection in the posterior thigh compartment is more likely to result in nerve injury. A better understanding of the inherent differences between tumors in various extremity sites will assist in individualizing treatment.

The General Surgeon's Quandary: Atypical Lipomatous Tumor vs Lipoma, Who Needs a Surgical Oncologist?

BACKGROUND Differentiating large lipomas from atypical lipomatous tumors (ALT) is challenging, and preoperative management guidelines are not well defined. The diagnostic ambiguity leads many surgeons to refer all patients with large lipomatous masses to an oncologic specialist, perhaps unnecessarily. STUDY DESIGN In this retrospective cohort study of patients with nonretroperitoneal lipomatous tumors, preoperative characteristics discernible without invasive diagnostic procedures were evaluated for diagnostic predictive value. RESULTS We identified 319 patients (256 with lipomas, 63 with ALTs) treated between 1994 and 2012. Patients with ALTs were older (60.5 vs 53.5 years, p < 0.0001), had larger tumors (16.0 vs 8.3 cm, p < 0.0001), had tumors more often located on an extremity (88.9% vs 60.5% torso, p < 0.0001), and more frequently had a history of previous operations at the same site, exclusive of excision leading to diagnosis and referral (20.6% vs 5.9%, p = 0.001). Local recurrence was observed in 2 patients with lipomas (0.8%) vs 14 with ALTs (22.6%, p < 0.0001). No patients with ALTs developed distant metastases or disease-specific mortality, with a median follow-up of 27.4 months (range 0 to 164.6 months). On multivariate analysis, age ≥ 55 years, tumor size ≥ 10 cm, extremity location, and history of previous resections were predictors for diagnosis of ALT (p < 0.05). CONCLUSIONS Characteristics of lipomatous masses associated with a diagnosis of ALT include patient age ≥ 55 years, tumor size ≥ 10 cm, previous resection, and extremity location (vs torso). These easily identifiable traits may guide surgical management or referral to a specialist.

Cryoablation of Osteoid Osteoma in the Pediatric and Adolescent Population.

PURPOSE To evaluate the technical feasibility and clinical efficacy of osteoid osteoma (OO) cryoablation in a large, pediatric/adolescent cohort. MATERIALS AND METHODS An electronic medical record and imaging archive review was performed to identify all cryoablations performed for OOs between 2011 and 2015 at a single tertiary care pediatric hospital. The subsequent analysis included 29 patients with suspected OOs treated by cryoablation (age range, 3-18 y; mean age, 11.3 y; 17 boys; 12 girls). Conventional CT guidance was used in 22 procedures; cone-beam CT guidance was used in 7 procedures. Follow-up data were obtained via a standardized telephone questionnaire (23/29 patients; 79.3%) and clinical notes (5/29 patients; 17.2%). One patient was lost to follow-up. RESULTS Technical success was achieved in 100% of patients (29/29). Immediate clinical success (cessation of pain and nonsteroidal antiinflammatory drug [NSAID] use within 1 mo after the procedure) was achieved in 27/28 patients (96.4%). Short-term clinical success (cessation of pain and NSAID use for > 3 mo after the procedure) was achieved in 24/25 patients (96%). Long-term clinical success (cessation of pain and NSAID use for > 12 mo after the procedure) was achieved in 19/21 patients (90.5%). Median pain scale score before the procedure was 10 (range, 5-10); median pain scale score after the procedure was 0 (range, 0-8; P < .0001). There were 6 minor complications (21%) and no major complications. CONCLUSION Image-guided cryoablation is a technically feasible, clinically efficacious therapeutic option for children and adolescents with symptomatic OO.

Percutaneous image-guided cryoablation for the treatment of phantom limb pain in amputees: a pilot study

PURPOSE To prospectively evaluate percutaneous image-guided nerve cryoablation for treatment of refractory phantom limb pain (PLP) in a pilot cohort for purposes of deriving parameters to design a larger, randomized, parallel-armed, controlled trial. MATERIALS AND METHODS From January 2015 to January 2016, 21 patients with refractory PLP underwent image-guided percutaneous cryoneurolysis procedures. Visual analog scale scores were documented at baseline and 7, 45, and 180 days after the procedure. Responses to a modified Roland Morris Disability Questionnaire were documented at baseline and 7 and 45 days after the procedure. RESULTS Technical success rate of the procedures was 100%. There were 6 (29%) minor procedure-related complications. Disability scores decreased from a baseline mean of 11.3 to 3.3 at 45-day follow-up (95% confidence interval 5.8, 10.3; P < .0001). Pain intensity scores decreased from a baseline mean of 6.2 to 2.0 at long-term follow-up (95% confidence interval 2.8, 5.6; P < .0001). CONCLUSIONS Image-guided percutaneous nerve cryoablation is feasible and safe and may represent a new efficacious therapeutic option for patients with phantom pains related to limb loss.

Aggressive (Epithelioid) Osteoblastoma Arising in Soft Tissue

Aggressive (epithelioid) osteoblastoma arising in soft tissue has never been described. It is important to differentiate this benign osteoblastoma, a potentially locally aggressive tumor, from extraskeletal osteosarcoma. This report describes an aggressive (epithelioid) osteoblastoma arising in a focus of heterotopic ossification in the axilla of a 21-year-old man.

Increase in PD-L1 expression after pre-operative radiotherapy for soft tissue sarcoma

ABSTRACT Soft tissue sarcomas (STS) have minimal expression of PD-L1, a biomarker for PD-1 therapy efficacy. Radiotherapy (RT) has been shown to increase PD-L1 expression pre-clinically. We examined the expression of PD-L1, pre- and post-RT, in 46 Stage II-III STS patients treated with pre-operative RT (50–50.4 Gy in 25–28 fractions) followed by resection. Five additional patients who did not receive RT were utilized as controls. PD-L1 expression on biopsy and resection samples was evaluated by immunochemistry using the anti PD-L1 monoclonal antibody (E1L3 N clone; Cell Signaling). Greater than 1% membranous staining was considered positive PD-L1 expression. Changes in PD-L1 expression were analyzed via the Fisher exact test. Kaplan-Meier statistics were used to correlate PD-L1 expression to distant metastases (DM) rate. The majority of STS were T2b (87.0%), high-grade (80.4%), undifferentiated pleomorphic histology (71.7%), and originated from the extremities (84.6%). Zero patients demonstrated PD-L1 tumor expression pre-RT. Post-RT, 5 patients (10.9%) demonstrated PD-L1 tumor expression (p = 0.056). Tumor associated macrophages (TAM) expression of PD-L1 increased after RT: 15.2% to 45.7% (p = 0.003). Samples from controls demonstrated no baseline (0%) or change in tumor PD-L1 expression. Freedom from DM was lower for patients with PD-L1 TAM expression post-RT (3 years: 49.7% vs. 87.8%, log-rank p = 0.006); TAM PD-L1 positivity remained an independent predictor for DM on multivariate analyses (Hazard ratio – 0.16, 95% confidence interval: 0.034–0.721, p = 0.042). PD-L1 expression on human STS tumor and TAM appears to elevate after pre-operative RT. Expression of PD-L1 on TAM after RT was associated with a higher rate of DM.