Benign ancient schwannoma of the abdominal wall: an unwanted birthday present

Ancient schwannoma in the right iliac fossa: A case report and review of literature

Ancient schwannomas are a rare variation of schwannomas, with the distinction being based on histopathological examination of the excised specimen. On histopathological examination, ancient schwannomas exhibit degenerative changes such as calcification, hyalinization, and cystic necrosis, along with S100 positivity. Complete surgical excision is the mainstay treatment for ancient schwannomas and carries a favorable prognosis. Recurrence is the most common complication, often arising from incomplete surgical excision. Herein, we present a case of a 41-year-old male who presented to our center as a case of a retroperitoneal mass for further investigations and diagnostic workup. Imaging showed a retroperitoneal mass in the right iliac fossa. We proceeded with ultrasound guided needle biopsy, and examination of the specimen confirmed the diagnosis of ancient schwannoma. Subsequently, the patient underwent surgery, and complete surgical excision was achieved. On follow-up 3-months later, the patient is doing well, and no signs of recurrence were found.

Outcomes after curatively intended treatment of limited peritoneal metastases and thermal ablation for liver metastases from colorectal cancer

Objectives

Peritoneal metastases (PM) and liver metastases (LM) are present simultaneously in up to 2 % of patients at the time of their colorectal cancer (CRC) diagnosis. Curatively intended treatment includes cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) combined with LM resection. A less invasive treatment for LM is ablation. We aimed to estimate overall survival (OS), disease-free survival (DFS) and postoperative data in patients managed simultaneously with CRS, HIPEC and radiofrequency ablation (RFA) as first choice.

Methods

This was a retrospective national cohort study. All patients were treated at Aarhus University Hospital; the only CRS+HIPEC centre in Denmark. We included CRC patients managed with curative intent for simultaneously diagnosed PM and LM in the period January 2016 - December 2021. LM was treated with RFA as first choice, if possible. Survival was calculated by the Kaplan-Meier method.

Results

A total of 25 patients were included, the median age was 60 years (range 43-75 years) and 15 (60 %) were females. The median peritoneal cancer index was 7 (range 0-12), the median number of LM was 1 (range 1-3). Ablation was performed as the only treatment for LM in 18 (72 %) patients. After a median follow-up time of 17.1 months (range 4-36 months), the median OS was 28.6 months (95 % confidence interval (Cl) 15.8;36.1), 1-year OS was 84.0 % (95 % Cl 62.8;93.7). Median DFS was 6.1 months (95 % Cl 4.0;10.3). Median LOS was ten days (range 5-26 days). Both 30-day and 90-day mortality were 0 %.

Conclusions

The selected treatment modality (RFA) for CRC patients with both LM and PM was safe. However, DFS was low. Further research is warranted to investigate if RFA is as effective as LM resection.

Lessons from a breast cell annotation competition series for school pupils

Due to COVID-19 outbreaks, most school pupils have had to be home-schooled for long periods of time. Two editions of a web-based competition “Beat the Pathologists” for school age participants in the UK ran to fill up pupils’ spare time after home-schooling and evaluate their ability on contributing to AI annotation. The two editions asked the participants to annotate different types of cells on Ki67 stained breast cancer images. The Main competition was at four levels with different level of complexity. We obtained annotations of four kinds of cells entered by school pupils and ground truth from expert pathologists. In this paper, we analyse school pupils’ performance on differentiating different kinds of cells and compare their performance with two neural networks (AlexNet and VGG16). It was observed that children tend to get very good performance in tumour cell annotation with the best F1 measure 0.81 which is a metrics taking both false positives and false negatives into account. Low accuracy was achieved with F1 score 0.75 on positive non-tumour cells and 0.59 on negative non-tumour cells. Superior performance on non-tumour cell detection was achieved by neural networks. VGG16 with training from scratch achieved an F1 score over 0.70 in all cell categories and 0.92 in tumour cell detection. We conclude that non-experts like school pupils have the potential to contribute to large-scale labelling for AI algorithm development if sufficient training activities are organised. We hope that competitions like this can promote public interest in pathology and encourage participation by more non-experts for annotation.

Schwannoma of the abdominal wall: updated literature review

Background

Schwannoma is a benign tumor arising from Schwann cells of the peripheral nerves. It is often asymptomatic and can develop in the retroperitoneum, mediastinum, head and neck region, and upper and lower extremities. Schwannoma of the abdominal wall is extremely rare, but differential diagnosis with malignant neoplasms is important to reduce the risk of undertreatment.

Methods

A narrative review of abdominal wall schwannoma was performed using PubMed, EMBASE, and Web of Science database and the search terms “schwannoma”, “neurinoma”, “neurilemmoma”, “soft tissue tumors”, “neurogenic tumor”, “rectus abdominis mass”, “abdominal wall”. In addition, the hospital charts were reviewed to report the personal experience.

Results

Only 9 single case-reports of benign schwannoma of the abdominal wall were found in the English medical literature over the past decade. None of the patients received preoperative biopsy and all were resected with clear margins. In addition to the literature review, we report the case of a 58-year-old man referred for a palpable mass in the left upper abdominal quadrant. Ultrasonography and magnetic resonance imaging revealed a solid and well-encapsulated mass inside the left rectus abdominis muscle. A core biopsy of the lesion provided the diagnosis of cellular schwannoma and this was confirmed by histopathologic examination of the surgical specimen.

Conclusions

Benign schwannoma of the abdominal wall is extremely rare. Percutaneous core needle biopsy is important for the differential diagnosis with more common and biologically more aggressive malignancies, such as desmoid tumors and sarcomas, and may be relevant for planning the most appropriate management.

Abdominal wall schwannoma: a case report

Schwannomas or neurilemmomas are benign and slow-growing tumors that arise exclusively from Schwann cells in peripheral nerve sheaths. These neoplasms theoretically can occur anywhere in the body, but they most frequently affect extremities, as well as head and neck region. However, their presentation in the abdominal wall is extremely rare and only few cases have been reported in the literature. Subcutaneous lesions may be asymptomatic and only incidentally discovered upon physical examination or imaging. However, occasionally they induce mass effects on surrounding large nerves. We present the case of a 34-year-old man with abdominal wall pain localized in the right iliac fossa and palpable subcutaneous mass. Ultrasound and CT scan revealed a solid well-defined mass of the abdominal wall. Following surgical excision under general anesthesia, histological examination was consistent with the diagnosis of benign schwannoma.

External Oblique Muscle Schwannoma: A Rare Anatomical Presentation

Introduction

Schwannomas or neurilemmomas are rare, benign, and usually solitary lesions that arise from the nerve sheath. In the majority of cases, these tumors involve the extremities, head, neck, and trunk.

Case Presentation

In the present study, a 52-year-old man presented to our surgical department for the evaluation of a symptomatic lump in his left lateral abdominal wall. CT and MRI confirmed the presence of a cystic mass located between the external and internal oblique muscles. Histopathology and immunohistochemistry confirmed it to be benign schwannoma.

Discussion

Schwannomas have rarely been reported in the abdominal wall. To the best of our knowledge, this is the first case of schwannoma located in the left upper abdominal wall and the fifth case of abdominal wall schwannoma reported according to the reviewed medical literature.

Conclusion

Benign schwannoma should be included in the differential diagnosis of cystic and symptomatic lesions of the abdominal wall. The treatment of choice is surgical excision, and recurrence is extremely rare.

Abdominal Wall Schwannoma

This rare form of subcutaneous nodule can be identified through the combination of imaging and biopsy, but the definitive diagnosis is made on complete excision of the mass.

Ancient Schwannoma of the Cauda Equina: Our Experience and Review of the Literature

Ancient schwannomas (AS) are exceedingly rare variant of common schwannomas (CS). Only two cases involving the cauda equina region have been previously reported in literature. AS are typically associated with a higher histological degree of degenerative changes (Antoni B areas). It is of peculiar importance, according to our opinion, to outline that, because of their extremely slow growth (which explains the increase of the degenerative changes in respect to the CS) and their typical soft consistency in respect to their standard counterparts, AS usually imply an even better prognosis.

Symptomatic schwannoma of the abdominal wall: A case report and review of the literature

Schwannoma is a rare, benign tumor that arises from the nerve sheath. This tumor usually involves the extremities, but can also be found in the head and neck, trunk, pelvis, retroperitoneum, mediastinum and gastrointestinal tract. In numerous cases, the tumors are asymptomatic and are identified incidentally on physical examination or imaging. Occasionally, schwannoma is symptomatic due to compression of surrounding large nerves. In the present study, a 57-year-old female presented to the surgical outpatient’s department due to a well-localized parietal pain in the left lower quadrant. The onset of the pain occurred three years prior to presentation, without apparent cause and in the absence of other symptoms. Ultrasound and a computed tomography scan revealed a small solid tumor in the anterior abdominal wall, which was dimensionally stable over time, but was not noted in a preliminary analysis by a radiologist. The lesion was surgically removed using an anterior surgical approach. Histopathology revealed the tumor to be benign schwannoma. The painful symptoms completely disappeared. To the best of our knowledge, this is the third case of an abdominal wall benign schwannoma in the medical literature, and the first symptomatic case.

Clinical skills development in student-run free clinic volunteers: a multi-trait, multi-measure study

BACKGROUND

At Wayne State University School of Medicine (WSU SOM), the Robert R. Frank Student Run Free Clinic (SRFC) is one place preclinical students can gain clinical experience. There have been no published studies to date measuring the impact of student-run free clinic (SRFC) volunteerism on clinical skills development in preclinical medical students.

METHODS

Surveys were given to first year medical students at WSU SOM at the beginning and end of Year 1 to assess perception of clinical skills, including self-confidence, self-reflection, and professionalism. Scores of the Year 1 Objective Structured Clinical Exam (OSCE) were compared between SRFC volunteers and non-volunteers.

RESULTS

There were a total of 206 (68.2%) and 80 (26.5%) survey responses at the beginning and end of Year 1, respectively. Of the 80 students, 31 (38.7%) volunteered at SRFC during Year 1. Statistically significant differences were found between time points in self-confidence (p < 0.001) in both groups. When looking at self-confidence in skills pertaining to SRFC, the difference between groups was statistically significant (p = 0.032) at both time points. A total of 302 students participated in the Year 1 OSCE, 27 (9%) of which were SRFC volunteers. No statistically significant differences were found between groups for mean score (p = 0.888) and established level of rapport (p = 0.394).

CONCLUSIONS

While this study indicated no significant differences in clinical skills in students who volunteer at the SRFC, it is a first step in attempting to measure clinical skill development outside of the structured medical school setting. The findings lend themselves to development of research designs, clinical surveys, and future studies to measure the impact of clinical volunteer opportunities on clinical skills development in future physicians.

Imaging observations of a schwannoma of low malignant potential in the anterior abdominal wall: A case report

Neurilemmoma, also known as schwannoma, is an uncommon benign neoplasm that is most commonly found in the trunk and head and neck regions. The present study reports the case of a 67-year-old female with schwannoma localized in the anterior abdominal wall and analyzes the ultrasound and computed tomography (CT) imaging observations of the schwannoma. A dynamic time-intensity curve was also recorded in the study. A well-defined, elliptic low echo level, heterogeneous mass was observed during ultrasound examination. The CT scan revealed a solid, heterogeneous, low-density mass in the abdominal wall. Contrast-enhanced scans showed a heterogeneously enhanced mass during the arterial and venous phase. Centripetal fill-in was demonstrated and the mass was markedly, homogenously enhanced relative to the muscles during the delayed phase. Peak enhancement was observed during the venous phase and then slowly declined. However, the mass was hyperattenuated during the delayed phase. The lesion was completely excised and no evidence of recurrence has been identified during the 3 months of follow-up. The present study suggested that a diagnosis of schwannoma should be considered for certain patients with masses in the abdominal wall. Peripheral enhancement during the arterial and venous phases and homogeneous enhancement in the delayed phase are the significant imaging findings of a schwannoma.

Abdominal wall schwannoma: case report and review of the literature

A 29-year-old female had presented to surgical outpatient's department complaining of lump in the anterior abdominal wall. Ultrasound and magnetic resonance imaging revealed a solid degenerated tumor in the anterior abdominal wall. It was surgically excised, and histopathology confirmed it to be “ancient” schwannoma. To our knowledge, this is the second reported case of an abdominal wall ancient schwannoma in the medical literature.

A predictive decision-aid methodology for dynamic mitigation of influenza pandemics

In a recent report, the Institute of Medicine has stressed the need for dynamic mitigation strategies for pandemic influenza. In response to the need, we have developed a simulation-based optimization methodology for generating dynamic predictive mitigation strategies for pandemic outbreaks affecting several regions. Our methodology can accommodate varying virus and population dynamics. It progressively allocates a limited budget to procure vaccines and antivirals, capacities for their administration, and resources required to enforce social distancing. The methodology uses measures of morbidity, mortality, and social distancing, which are translated into the costs of lost productivity and medical services. The simulation model was calibrated using historic pandemic data. We illustrate the use of our methodology on a mock outbreak involving over four million people residing in four major population centers in Florida, USA. A sensitivity analysis is presented to estimate the impact of changes in the budget availability and variability of some of the critical parameters of mitigation strategies. The methodology is intended to assist public health policy makers.