Diagnostic value of tumor-fascia relationship in superficial soft tissue masses on magnetic resonance imaging

Organ dependency on fascia connective tissue

Fascia is a specialized connective tissue system that encapsulates and interconnects between tissues and organs throughout the body. The fascia system regulates pain sensation, organ inflammation, trauma, and fibrotic diseases. This mini-review summarizes recent findings from animal models, which reveal the inter-dependency between tissues/organs and the fascia system. Special mechanisms are explored of fascia response to skin inflammatory processes and fibrotic microenvironments in trauma models. We highlight the functionally diverse communities of its fascia-born fibroblasts and the significance of their stage-specific differentiation and communication to disease progression. Understanding the molecular mechanisms and cellular processes within the fascia microenvironment may serve as a basis for future clinical translation.

Case report: Giant atypical granular cell tumor of the median nerve

Granular cell tumors are extremely uncommon soft tissue neoplasms that mostly occur in the head and neck regions. Granular cell tumors are generally benign, asymptomatic, and rarely involve the median nerve. Due to the lack of awareness about granular cell tumors, they are easily misdiagnosed and mistreated in primary hospitals. Here, we report a giant atypical granular cell tumor located on the median nerve, approximately 12 cm in size, with unusual symptoms of median nerve damage. Magnetic resonance imaging revealed a fusiform mass that was hyperintense on T2-weighted images and iso-hypointense on T1-weighted images. The mass was subsequently biopsied and found to be a granular cell tumor. The tumor was resected, and a pathological examination was performed. Pathological examination revealed necrotic foci, abundant eosinophilic granules, pustular ovoid bodies, and multiple mitoses. Immunohistochemical staining revealed that the tumor cells were positive for S-100, CD68, SMA, SOX-10, Calretinin, and TFE3. The integrated diagnosis was an atypical granular cell tumor. To the best of our knowledge, this is the first report of an atypical granular cell tumor involving the median nerve. Furthermore, we comprehensively reviewed the existing literature to provide a concise summary of the diagnostic criteria, imaging findings, and pathological features of granular cell tumors. Given the high recurrence and metastasis rates of this disease, granular cell tumors of the median nerve should be considered when a patient presents with symptoms of median nerve impairment. The diagnosis of atypical granular cell tumors relies on pathological examination. In addition, extensive resection and long-term follow-up are necessary to improve prognosis.

Small (≤5 cm) soft tissue tumors of the extremity and superficial trunk: MRI features and demographic characteristics associated with malignancy

Background

Although a substantial proportion of small soft tissue tumors are malignant, magnetic resonance imaging (MRI) features and demographic characteristics associated with these tumors have not been well described.

Purpose

To investigate the MRI features and demographic characteristics associated with small (≤5 cm) malignant soft tissue tumors, and to identify independent predictors that allow differentiation of small benign and malignant soft tissue tumors.

Material and Methods

This retrospective study evaluated patients who underwent surgical excision of small soft tissue tumors of the extremities and superficial trunk, and preoperative contrast-enhanced MRI. Seven MRI findings (tumor depth, tumor-fascia relationship, heterogeneity of signal intensity, necrosis, peritumoral edema, peritumoral enhancement, and margin) and two demographic parameters (age and sex) were included in univariate and multivariate logistic regression analyses to identify independent predictors of small malignant soft tissue tumors.

Results

A total of 221 patients (102 men; mean age=45.6 ± 17.6 years) with 72 malignant and 149 benign tumors were included. In the univariate analysis, peritumoral edema (odds ratio [OR] = 3.854; P < 0.001) and peritumoral enhancement (OR = 3.966; P < 0.001) and patient age (≥46 years) (OR = 2.154; P = 0.009) were significantly associated with malignancy. Multivariate analysis showed that peritumoral enhancement on MRI (OR = 3.728; P < 0.001) and patient age (≥46 years) (OR = 1.907; P = 0.036) were independent predictors of malignancy. The combination of these two parameters showed accuracy of 75.1%, sensitivity of 55.6%, and specificity of 84.6% to predict malignancy.

Conclusion

Among several MRI and demographic features, the presence of peritumoral enhancement on MRI and patient age (≥46 years) were independent predictors of malignancy in small soft tissue tumors.

Tumor-skin invasion is a reliable risk factor for poor prognosis in superficial soft tissue sarcomas

Introduction

Superficial soft tissue sarcomas are often left untreated unless they invade the skin and skin ulcers manifest. Progressive sarcomas frequently result in dismal oncological outcomes despite multidisciplinary treatment. This study aimed to identify prognostic factors for superficial soft tissue sarcomas.

Materials and methods

This study retrospectively analyzed the clinicopathological data of 82 patients with superficial soft tissue sarcomas treated between August 2003 and December 2020 at our institution. A superficial soft tissue sarcoma was defined if the percentage of the area occupied by the tumor in the assessed region (skin, subcutaneous) was more than 50%. Age, sex, location, tumor size, tumor-skin invasion, tumor grade, and distant metastasis at initial diagnosis were evaluated as potential prognostic factors. Cox proportional hazards regression models were used to identify the prognostic factors. Five-year survival rates were assessed by the Kaplan-Meier method.

Results

The mean follow-up time was 60.1 months. The 5-year overall survival, 5-year local recurrence-free survival, and 5-year metastasis survival rates were 76.4%, 60.6%, and 71.0%, respectively. Univariate analysis showed significant relationships between poor prognosis and tumor size ≥5 cm, distant metastasis at initial diagnosis, and tumor-skin invasion. In the multivariate analysis, only the tumor-skin invasion was associated with worse overall survival.

Conclusions

Superficial soft tissue sarcomas have biologically been considered a separate category due to their better prognosis. In this study, the tumor-skin invasion was the only significant factor associated with a poor prognosis. Therefore, all superficial soft tissue sarcomas without tumor-skin invasion should be treated as early as possible.

Clinical characteristics of patients with undergoing unplanned excisions of malignant soft tissue tumors

INTRODUCTION

Malignant soft tissue tumors are rare tumors representing <1% of all malignancies. As these tumors are rare, it is not uncommon that malignant soft tissue tumor excision is performed without the required preoperative imaging, staging, or wide resection margins for sarcomas. The purpose of this study was to investigate the characteristics of patients with undergoing unplanned excisions. Risk factors for tumor recurrence and mortality in patients treated with unplanned excisions were also analyzed.

METHODS

Forty-nine patients who underwent unplanned excision at other hospitals and additional wide excision at our hospital between January 2002 and December 2018 were identified. Among them, 42 patients with follow-up for more than 1 year were included in this retrospective study. The relationships between sex, age, tumor depth, histological grade, location, size, surgical margin at additional wide excision, residual tumor, reconstruction, kind of hospital where the primary excision was done (sarcoma vs non-sarcoma center), preoperative examination, chemotherapy, radiation therapy, and oncological outcomes were statistically analyzed.

RESULTS

Mean patient age was 57.3 years (15-85 years) and the mean observation period was 72.5 months (14-181 months). This analysis showed 53.8% tumors that underwent unplanned excisions were small (<5 cm) and 70.7% tumors were superficial. Multivariate analysis revealed that a positive margin during additional wide excision was significantly associated with a lower 5-year LRFS (p < 0.01).

CONCLUSION

Most of the tumors underwent unplanned excisions were small (<5 cm) and superficial. Surgeons should be aware that a positive margin during additional wide excision is an independent risk factor for local recurrence.

Cutting into wound repair

The skin is home to an assortment of fibroblastic lineages that shape the wound repair response toward scars or regeneration. In this review, we discuss the distinct embryonic origins, anatomic locations, and functions of fibroblastic lineages, and how these distinct lineages of fibroblasts dictate the skin's wound response across injury depths, anatomic locations, and embryonic development to promote either scarring or regeneration. We highlight the supportive role of the fascia in dictating scarring outcomes; we then discuss recent findings that indicate fascia mobilization by its resident fibroblasts supersede the classical de novo deposition program of wound matrix formation. These recent findings reconfigure our traditional view of wound repair and present exciting new therapeutic avenues to treat scarring and fibrosis across a range of medical settings.

The differential diagnosis of trunk and extremity dermal and sub-dermal lesions referred to a musculoskeletal oncology service

OBJECTIVES

To determine the differential diagnosis of dermal and sub-dermal soft tissue masses which do not extend to the deep fascia that are referred to a specialist musculoskeletal oncology service.

MATERIALS AND METHODS

Review of all patients referred to a specialist musculoskeletal oncology service over a 13-month period with a dermal or sub-dermal soft tissue mass which did not extend to the deep fascia based on MRI appearances. Data collected included age, gender, site and maximal lesion size, and final histological diagnosis for biopsied and/or excised lesions.

RESULTS

56 patients were included, 21 (37.5%) males and 35 (62.5%) females with mean age 49.75 years (range 5-86 years). 3 patients had 2 lesions making a total of 59 lesions, 11 (18.6%) dermal and 48 (81.4%) sub-dermal. Histological diagnosis was available in 44 (74.6%) cases, of which 11 (25%) were non-neoplastic, 23 (52.3%) were benign neoplasms, and 10 (22.7%) were malignant neoplasms. Although older age at presentation and greater mean maximal tumour dimension were seen with malignant lesions, these did not reach statistical significance (p = 0.154 and 0.102 respectively). There was also no relationship between skin involvement from sub-dermal lesions and malignancy, but 5 of 6 dermal lesions which showed an exophytic growth pattern were malignant.

CONCLUSIONS

The differential diagnosis of dermal and sub-dermal lesions which do not reach the deep fascia is wide with a malignant lesion being the cause in almost one-quarter of cases.

Small indeterminate superficial soft tissue masses: relationship between depth and histological grade

OBJECTIVE

To determine whether the location of a small, indeterminate soft tissue mass within the subcutaneous compartment is related to its histological grade.

METHODS

All Sarcoma Service referrals over a 12 month period of small (<3 cm) superficial soft tissue masses, indeterminate by MRI evaluation which subsequently underwent primary excision biopsy were included. Lesions were categorised by their anatomical location in the subcutaneous compartment. Histopathological diagnoses were categorized according to12 WHO 2013. χ2 statistical analysis was performed to determine the relationship between lesion depth and histological grade.

RESULTS

The study included 43 patients, mean age 42 years (range 15-71 years). Within the subcutaneous compartment, 16 lesions were categorized as superficial, 9 lesions central and 18 lesions deep, of which 9 were non-neoplastic, 29 benign, 1 intermediate-grade and 4 malignant. Location in the deep aspect of the subcutaneous compartment was associated with a higher risk of intermediate or malignant histology (p = 0.02).

CONCLUSION

The location of a small, indeterminate soft tissue mass within the subcutaneous compartment may be an indicator of histological aggressiveness. Lesions in the deep subcutaneous compartment are more likely to be intermediate-grade/malignant lesions. Therefore, if considering excision biopsy as definitive treatment, a wider margin may be appropriate.

ADVANCES IN KNOWLEDGE

Small, indeterminate soft tissue masses can be aggressive and the anatomical depth within the subcutaneous tissue may be a potential indicator of histological aggressiveness.