[Large excoriated pleomorphic liposarcoma]

Pleomorphic liposarcoma is a rare and aggressive tumour developed from mesenchymal tissue. The clinical presentation is most often a subcutaneous mass syndrome. The surgical excision of such lesions has both a therapeutic and diagnostic confirmation value. We here report the case of a 41-year-old woman with a voluminous gluteal lesion that required surgical treatment.

Desmoid Tumors: A Comprehensive Review

Desmoid tumors (DT) are rare, locally aggressive, fibroblastic soft-tissue tumors that are characterized by infiltrative growth and can affect organs and adjacent structures, resulting in substantial clinical burden impacting patients' health-related quality of life. Searches of PubMed, Embase, Cochrane, and key conferences were conducted in November 2021 and updated periodically through March 2023 to identify articles describing the burden of DT. Of 651 publications identified, 96 relevant ones were retained. Diagnosis of DT is challenging because of its morphologic heterogeneity and variable clinical presentation. Patients visit multiple healthcare providers, often facing delays in correct diagnosis. The low incidence of DT (estimated 3-5 cases per million person-years) limits disease awareness. Patients with DT experience a high symptom burden: up to 63% of patients experience chronic pain, which leads to sleep disturbance (73% of cases), irritability (46% of cases), and anxiety/depression (15% of cases). Frequently mentioned symptoms are pain, limited function and mobility, fatigue, muscle weakness, and swelling around the tumor. Overall, quality of life in patients with DT is lower than in healthy controls. There is no treatment approved by the US Food and Drug Administration for DT; however, treatment guidelines reference available options, such as active surveillance, surgery, systemic therapy, and locoregional therapy. Choice of active treatment may depend on tumor location, symptoms, and risk of morbidity. The substantial burden of illness of DT is related to difficulties in timely and accurate diagnosis, high symptom burden (pain and functional limitations), and decreased quality of life. There is a high unmet need for treatments that specifically target DT and improve quality of life.

The reproducibility of MTV and TLG of soft tissue tumors calculated by FDG-PET: Comparison between the lower limit by the fixed value SUV 2.5 and that value by 30% of SUVmax

PURPOSE

We evaluated the reproducibility calculating volume-based FDG-PET/CT parameters, i.e., metabolic tumor volume (MTV) and total lesion glycolysis (TLG), in soft tissue tumors.

MATERIALS AND METHODS

Fifty-three cases with soft tissue tumors were analyzed retrospectively. The conditions determining the lower limit of MTV were fixed value SUV 2.5 or 30% of SUVmax. To investigate the agreement of the measurements by two radiologists, %difference, the correlation coefficients and Bland-Altman plot were analyzed. We compared these parameters in both intra- and inter-operator for evaluating the agreement in the measurements.

RESULTS

The values of % difference were excellent, 0.2-3.5%, in the intra-operator in all calculated volume-based parameters. In both inter- and intra-operator analysis, the values of % differences were lower in the parameters calculated by SUV 2.5 fixed value as a lower threshold compared with those calculated by 30% of SUVmax as a lower threshold. The correlation coefficient in MTV30% for inter-operator were 0.84 or 0.87, those were lower than values by the intra-operator evaluation. Nevertheless, the correlation coefficients were higher than 0.84 in every parameter. Particularly, correlation coefficient in the parameters calculated by SUV 2.5 fixed value was better than those calculated by 30% of SUVmax. The Bland-Altman plot analysis showed good agreement for all parameters, particularly in the intra-operator examinations. However, in the inter-operator study, some variances were noted in every condition.

CONCLUSION

In conclusion, the reproducibility of measuring volume-based FDG-PET/CT parameters of soft tissue tumors was good, particularly, in the measurement by fixed lower limit value SUV 2.5 in the intra-operator.

Multi-parametric MRI-based radiomics for the diagnosis of malignant soft-tissue tumor

PURPOSE

To develop and validate a multiparametric magnetic resonance imaging-based radiomics nomogram for differentiating malignant and benign soft-tissue tumors.

METHODS

A total of 91 patients with pathologically confirmed soft-tissue tumors were enrolled between January 2017 and October 2020. Forty-eight patients were consecutively enrolled between November 2020 and March 2022, as a time-independent cohort. All patients underwent contrast-enhanced T1-weighted and T2-weighted fat-suppression magnetic resonance scans at 3.0 T. Radiomics features were extracted and selected from the two modalities to develop the radiomics signature. Significant clinical/morphological characteristics were identified using a multivariate logistic regression analysis. The least absolute shrinkage and selection operator regression were applied to identify discriminative features. A clinical-radiomics nomogram was constructed based on clinical/morphological characteristics and radiomics features. Finally, the performance of the nomogram was validated using the receiver operating characteristic and decision curve analysis (DCA).

RESULTS

Six features were selected to establish the combined RS. Size, margin, and peritumoral edema were identified as the most important clinical and morphological factors, respectively. The radiomics signature outperformed the clinical model in terms of AUC and sensitivity. The nomogram integrating the combined RS, size, margin, and peritumoral edema achieved favorable predictive efficacy, generating AUCs of 0.954 (95% confidence interval [CI]: 0.907-1.000, Sen = 0.861, Spe = 0.917), 0.962 (95% CI: 0.901-1.000, Sen = 0.944, Spe = 0.923), and 0.935 (95% CI: 0.871-0.998, Sen = 0.815, Spe = 0.952) in the training (n = 60), validation (n = 31) and time-independent (n = 48) cohorts, respectively. The DCA curve indicated good clinical usefulness of the nomogram.

CONCLUSIONS

Our study demonstrated the clinical potential of multiparametric MRI-based radiomics in distinguishing malignant from benign soft-tissue tumors, which can be considered as a noninvasive tool for individual treatment management.

Ultrasonography of Pediatric Superficial Soft Tissue Tumors and Tumor-Like Lesions

Ultrasonography (US) is usually the first imaging examination performed to evaluate palpable or visible superficial soft tissue lesions that are common in children. Although clinical assessments, such as age at presentation, clinical course, and overlying skin discoloration, are important for the differentiation of pediatric soft tissue lesions, US allows a specific diagnosis of some typical benign lesions and helps in guiding further investigation since it provides detailed information about the lesion location, characterization including solid versus cystic, vascularity, and compressibility. Therefore, sufficient knowledge of the normal anatomy, proper ultrasonographic techniques, and the imaging findings of common and uncommon soft tissue lesions in children are crucial for accurate assessment and management of patients. In this article, we review the techniques and imaging findings focusing on the ultrasonographic features of a variety of superficial soft tissue lesions detected in children.

Accuracy of histological grades from intraoperative frozen-section diagnoses of soft-tissue tumors

BACKGROUND

For excised tumor specimens, histological grades can differ between the biopsy diagnosis and the final diagnosis.

METHODS

We retrospectively investigated the diagnostic accuracies of histological grades for frozen-section and permanent-section diagnoses from patients with soft-tissue tumors. Frozen-section, permanent-section, and final diagnoses were classified as benign tumors/tumor-like lesions, intermediate malignancies, or malignant tumors. Diagnostic accuracies of the histological grades from the frozen and permanent sections were evaluated by comparing the final diagnoses for the resected specimens.

RESULTS

The diagnostic accuracies of the histological grades for the frozen- and permanent-section diagnoses were 95% (387/408 lesions) and 97% (395/408 lesions), respectively. Among the tumor types, the diagnostic accuracies of the histological grades for the frozen-section and permanent-section diagnoses were 84% and 87% for adipocytic tumors, 87% and 91% for fibroblastic/myofibroblastic tumors, 99% and 100% for nerve-sheath tumors, 98% and 98% for fibrohistiocytic tumors, 90% and 98% for tumors of uncertain differentiation, 100% and 100% for vascular tumors, and 97% and 98% for other tumors, respectively.

CONCLUSIONS

Histological grades from frozen-section diagnoses yielded low diagnostic accuracies in adipocytic and fibroblastic/myofibroblastic tumors. Treatment should be planned based on permanent-section diagnosis and radiological findings for these tumors.

Intracranial Ewing Sarcoma - A case report

Background:

Intracranial Ewing’s sarcoma (ES) is a rare entity with <15 cases reported in the literature. It belongs to a family of round-cell neuroectodermally derived tumors bearing many similarities to peripheral primitive neuroectodermal tumor (pPNET). There is currently no established treatment protocol. Reported cases are treated with either surgery alone or surgery with adjuvant chemotherapy and radiation.

Case Description:

We describe a case of intracranial left frontal ES in a 19-year-old patient who presented with change in behavior. Diagnosis was unclear based on radiological findings on MRI and CT alone. MRI brain with contrast demonstrated a large extra-axial ovoid heterogeneously enhancing left frontal convexity mass. The patient underwent gross total resection with adjuvant chemotherapy and radiation. No local or systemic recurrence was found at 12 months postoperatively.

Conclusion:

Intracranial ES/pPNET is rare tumor with nonspecific clinical presentation and radiological findings. They are locally invasive. Surgery with adjuvant chemoradiation is the mainstay treatment. Distinction of pPNET and cPNET is important for therapeutic and prognostic purposes.

Clinical significance of thermal detection of soft-tissue tumors

BACKGROUND

Soft-tissue tumors are often accompanied by abnormal temperature distribution detected during palpation. However, the assessment of temperature distribution is subjective, limiting its wide use in cancer screening. The aim of this study was to evaluate the clinical significance of the thermal detection of soft-tissue tumors.

METHODS

This study involved 100 soft-tissue tumor patients, the pathological diagnosis of which was confirmed by surgery from February 2017 to March 2019 in our hospital. Sixty patients were diagnosed with benign lesions, while 40 patients had malignant tumors. The cohort consisted of 52 males and 48 females, with a median age of 62 (range 22-84). Temperature difference detection by orthopedic oncologists, as well as the consistency and accuracy of temperature distribution detection by orthopedic oncologists, were investigated. The relationship between abnormal temperature distribution and the presence of malignancy in soft tissue was also explored.

RESULTS

We found that more than half of the orthopedic oncologists could detect a temperature difference of 0.2 °C or higher. All three surgeons reported consistent temperature distribution findings after palpation in 92 out of 100 soft-tumor patients. The presence of abnormal temperature distribution was significantly associated with the presence of malignancy (P < 0.0017). Temperature differences of 0.2 °C or higher were significantly associated with the presence of malignant tumors (P < 0.001).

CONCLUSIONS

Diagnosis of abnormal temperature distribution by orthopedic oncologists could suggest the presence of malignancy in patients with soft-tissue lesions.

Sonographic Appearances of Liposarcoma: Correlations with Pathologic Subtypes

Liposarcoma is the second most common malignant soft-tissue tumor. This entity is pathologically categorized into 4 subtypes: well-differentiated, myxoid, dedifferentiated and pleomorphic. Although features on magnetic resonance imaging and computed tomography for these 4 subtypes have been reported quite precisely, those on sonography have not been fully investigated. The present study was therefore aimed at clarifying the sonographic appearances of each liposarcoma subtype and assessing correlations with histopathology. The study population was made up of 35 cases, including 21 cases of well-differentiated liposarcoma, 6 cases of myxoid liposarcoma, 6 cases of dedifferentiated liposarcoma and 2 cases of pleomorphic liposarcoma. Compared with the other subtypes, well-differentiated liposarcoma was characterized by the high frequency of the following findings: isoechogenicity, tiny hyperechoic lines and hypovascularity (p < 0.01, in each). Myxoid liposarcomas were characterized by low echogenicity, intermingled with anechoic areas and moderate vascularity (p < 0.01, in each). Dedifferentiated liposarcomas showed a specific biphasic pattern of hyperechoic and hypoechoic areas and hypervascularity (p < 0.01, in each). Pleomorphic liposarcomas showed a specific gyrus-like mixture of hyperechoic and hypoechoic areas (p < 0.01). In conclusion, the present study revealed different characteristics of sonographic appearance among the 4 histopathologic subtypes of liposarcoma.

Imaging appearances of soft-tissue tumors of the pediatric foot: review of a 15-year experience at a tertiary pediatric hospital

Tumors of the foot are rare in children. In this review the authors illustrate radiographic, sonographic and MR imaging findings of foot soft-tissue tumors in children based on all cases presenting at a tertiary pediatric hospital during the 15-year period of 1999-2014. Among these cases there were 155 tumors of the foot - 72 of the bones and 83 of the soft tissues. Vascular malformations, fibromatosis and sarcomas were respectively the most frequent benign, intermediate and malignant soft-tissue tumors. Some tumors showed specific imaging findings. In imaging investigations, ultrasound can be used as the first imaging modality for diagnostic workup of most lesions because it is noninvasive, low-cost and readily available, and can confirm the presence of the mass and evaluate cystic components, especially in young children who would otherwise require sedation for MR imaging. MR imaging is the reference standard technique because of its high tissue contrast, which allows for detection and characterization of soft-tissue and bone abnormalities. MR imaging is useful as the first imaging modality in select cases, including those with high suspicion of malignancy, very large lesions or pre-treatment lesions. Recognition of some typical imaging findings in pediatric soft-tissue foot tumors is helpful to establish diagnosis and facilitate patient management.

Magnetic resonance imaging appearance of soft-tissue metastases: our experience at an orthopedic oncology center

OBJECTIVE

To assess the prevalence and magnetic resonance imaging appearance of metastasis presenting as a soft-tissue mass.

MATERIALS AND METHODS

A retrospective chart review was performed on 51 patients who presented to an orthopedic oncology center with soft-tissue masses, with a histology-proven diagnosis of soft-tissue metastasis, over a 14-year period. Their magnetic resonance imaging, primary origin, and follow-up have been assessed.

RESULTS

Soft-tissue metastasis was identified in patients ranging from 18 to 85 years old. Most (80%) of the masses were located deep to the deep fascia. In our cohort of patients, melanoma was the most common primary malignancy contributing to soft-tissue metastasis (21.8%). Among soft-tissue metastasis from solid organs, breast and lung were the most frequent (9.1% each). Five patients had soft-tissue metastases from an unknown primary.

CONCLUSION

Imaging diagnosis of soft-tissue metastases is challenging as it can demonstrate imaging appearances similar to primary soft-tissue sarcoma. The presence of a known malignancy may not be evident in everyone, and even if available, histopathology will be necessary for diagnosis if this is the only site of recurrence/metastasis to differentiate from a primary soft-tissue sarcoma. Moreover, soft-tissue metastasis may be the initial presentation of a malignancy. Primary malignancies with soft-tissue metastasis carry a poor prognosis; hence, prompt diagnosis and management in essential.

Localized and diffuse forms of tenosynovial giant cell tumor (formerly giant cell tumor of the tendon sheath and pigmented villonodular synovitis)

Tenosynovial giant cell tumor (TSGCT) is a rare benign tumor arising from joint synovia, bursae and tendon sheaths. Their variable clinical presentation is related to variations in site and progression. Localized forms are most frequent in the hands, and diffuse forms in the knee. MRI is necessary and sometimes sufficient for diagnosis. Treatment strategy is guided by progression, symptomatology, location and diathesis. Optimally complete resection is the principle of first-line treatment. Radiation therapy is effective and targeted therapies are promising; both should especially be considered in case of relapse.

MR Imaging of Soft-Tissue Tumors of the Upper Extremity

Certain soft-tissue tumors seem to be specific to the upper extremity; most are benign. Knowledge of key magnetic resonance features, with clinical history and epidemiologic knowledge, can assist the radiologist in establishing optimal diagnosis. Indeterminate lesions require biopsy to exclude malignancy.

Angiolipoma of the labia majora: MR imaging findings with histopathological correlation

Benign soft tissue tumors of the vulva are relatively rare in adult patients. We present the magnetic resonance (MR) imaging features of an angiolipoma of the labia majora that developed in a 58-year-old woman. MR imaging showed a well-circumscribed lesion that was hyperintense on T1-weighted and T2-weighted MR images, and hypointense on fat-suppressed MR images, consistent with fat content. High apparent diffusion coefficient was noticed on diffusion-weighted MR images. Dynamic gadolinium-chelate enhanced MR imaging showed progressive enhancement. Histopathologically, the lesion was predominantly made of mature adipose tissue and contained thin walled vascular channels consistent with angiolipoma.