Utility of artificial intelligence in a binary classification of soft tissue tumors

Soft tissue tumors (STTs) pose diagnostic and therapeutic challenges due to their rarity, complexity, and morphological overlap. Accurate differentiation between benign and malignant STTs is important to set treatment directions, however, this task can be difficult. The integration of machine learning and artificial intelligence (AI) models can potentially be helpful in classifying these tumors. The aim of this study was to investigate AI and machine learning tools in the classification of STT into benign and malignant categories. This study consisted of three components: (1) Evaluation of whole-slide images (WSIs) to classify STT into benign and malignant entities. Five specialized soft tissue pathologists from different medical centers independently reviewed 100 WSIs, representing 100 different cases, with limited clinical information and no additional workup. The results showed an overall concordance rate of 70.4% compared to the reference diagnosis. (2) Identification of cell-specific parameters that can distinguish benign and malignant STT. Using an image analysis software (QuPath) and a cohort of 95 cases, several cell-specific parameters were found to be statistically significant, most notably cell count, nucleus/cell area ratio, nucleus hematoxylin density mean, and cell max caliper. (3) Evaluation of machine learning library (Scikit-learn) in differentiating benign and malignant STTs. A total of 195 STT cases (156 cases in the training group and 39 cases in the validation group) achieved approximately 70% sensitivity and specificity, and an AUC of 0.68. Our limited study suggests that the use of WSI and AI in soft tissue pathology has the potential to enhance diagnostic accuracy and identify parameters that can differentiate between benign and malignant STTs. We envision the integration of AI as a supportive tool to augment the pathologists' diagnostic capabilities.

Diagnostic Performance of Radiomics and Deep Learning to Identify Benign and Malignant Soft Tissue Tumors: A Systematic Review and Meta-analysis

RATIONALE AND OBJECTIVES

To systematically evaluate the application value of radiomics and deep learning (DL) in the differential diagnosis of benign and malignant soft tissue tumors (STTs).

MATERIALS AND METHODS

A systematic review was conducted on studies published up to December 11, 2023, that utilized radiomics and DL methods for the diagnosis of STTs. The methodological quality and risk of bias were evaluated using the Radiomics Quality Score (RQS) 2.0 system and Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool, respectively. A bivariate random-effects model was used to calculate the summarized sensitivity and specificity. To identify factors contributing to heterogeneity, meta-regression and subgroup analyses were performed to assess the following covariates: diagnostic modality, region/volume of interest, imaging examination, study design, and pathology type. The asymmetry of Deeks' funnel plot was used to assess publication bias.

RESULTS

A total of 21 studies involving 3866 patients were included, with 13 studies using independent test/validation sets included in the quantitative statistical analysis. The average RQS was 21.31, with substantial or near-perfect inter-rater agreement. The combined sensitivity and specificity were 0.84 (95% CI: 0.76-0.89) and 0.88 (95% CI: 0.69-0.96), respectively. Meta-regression and subgroup analyses showed that study design and the region/volume of interest were significant factors affecting study heterogeneity (P < 0.05). No publication bias was observed.

CONCLUSION

Radiomics and DL can accurately distinguish between benign and malignant STTs. Future research should concentrate on enhancing the rigor of study designs, conducting multicenter prospective validations, amplifying the interpretability of DL models, and integrating multimodal data to elevate the diagnostic accuracy and clinical utility of soft tissue tumor assessments.

Recent advances in molecular profiling of bone and soft tissue tumors

The molecular characterization of soft tissue and bone tumors is a rapidly evolving field that has changed the perspective of how these tumors are diagnosed today. Morphology and clinico-radiological context still represent the cornerstone of diagnostic considerations but are increasingly complemented by molecular data that aid in objectifying and confirming the classification. The spectrum of analyses comprises mutation or gene fusion specific immunohistochemical antibodies, fluorescence in situ hybridization, DNA and RNA sequencing as well as CpG methylation profiling. This article provides an overview of which tools are presently available to characterize bone and soft tissue neoplasms molecularly, what limitations should be considered, and what conclusions can be drawn from the individual findings.

Cryoablation for Bone and Soft Tissue Lesions in Pediatric Patients: Complications and Preventive Measures

PURPOSE

To evaluate complications associated with cryoablation in a pediatric population and review preventive measures to mitigate these complications.

MATERIAL AND METHODS

Retrospective study including all the image guided cryoablations performed on pediatric population. Immediate and delayed complications were analyzed, and we identified the different protective measures used and the clinical outcomes from follow-up. Point estimates for the percentage of complications were calculated by maximum likelihood, and 95% confidence intervals for the true percentages were calculated using the Clopper-Pearson exact method.

RESULTS

Eighty-seven ablations were performed on 68 patients (age range of 2-18 years, mean 12.4 years) for non-neoplastic (70%) and neoplastic (30%) lesions. The percentage of ablations resulting in complications was 18% (95% confidence interval (CI) 11% to 28%). Of these, 5% (95% CI 1% to 11%) were grade 3 complications, and 14% (95% CI 7% to 23%) were grade 2 complications. Thermal protection was performed in 27.6% of ablations (n = 24). The mean clinical follow-up duration was 348 days.

CONCLUSION

Cryoablation in pediatric patients is relatively safe, with a major complication rate per ablation of 5%. Thermal protective measures can be considered to mitigate these complications.

Gardner syndrome: A case report

BACKGROUND

Gardner syndrome (GS) is a rare autosomal dominant hereditary disorder. Since GS often has multi-system involvement with diverse clinical manifestations, misdiagnosis is common. Herein we report a case of GS.

CASE SUMMARY

A 38 year-old women presented with intermittent abdominal distension, nausea, and vomiting for 15 mo, which was aggravated for 1 wk. Related tests showed gastrointestinal adenoma and multiple desmoid tumors in the abdominal wall and abdominal cavity, and gene sequencing confirmed the diagnosis of GS. The patient underwent endoscopic intestinal polypectomy and symptomatic treatment, and her symptoms were relieved. Later, the patient's symptoms recurred and became worse than before. Gastrointestinal anastomosis was performed, and the patient had no postoperative discomfort. Finally, her condition improved.

CONCLUSION

The clinical manifestations of GS are varied, and the appearance of extraenteral manifestations before intestinal polyps is very important for the early identification of such patients, so as to achieve early treatment and improve the prognosis.

Postoperative drainage management and wound complications following resection of lower limb soft tissue tumors: a retrospective cohort study

PURPOSE

Postoperative wound complications are common in patients undergoing resection of lower extremity soft tissue tumors. Postoperative drainage therapy ensures adequate wound healing but may delay or complicate it. The aim of this study is to evaluate the incidence of postoperative wound complications and delayed or prolonged drainage treatment and to propose a standardized definition and severity grading of complex postoperative courses.

METHODS

A monocentric retrospective analysis of 80 patients who had undergone primary resection of lower extremity soft tissue tumors was performed. A new classification was developed, which takes into account postoperative drainage characteristics and wound complications. Based on this classification, risk factors and the prognostic value of daily drainage volumes were evaluated.

RESULTS

According to this new definition, regular postoperative course grade 0 (no wound complication and timely drainage removal) occurred in 26 patients (32.5%), grade A (minor wound complications or delayed drainage removal) in 12 (15.0%), grade B (major wound complication or prolonged drainage therapy) in 31 (38.8%), and grade C (reoperation) in 11 (13.7%) patients. Tumor-specific characteristics, such as tumor size (p = 0.0004), proximal tumor location (p = 0.0484), and tumor depth (p = 0.0138) were identified as risk factors for complex postoperative courses (grades B and C). Drainage volume on postoperative day 4 was a suitable predictor for complex courses (cutoff of 70 ml/d).

CONCLUSION

The proposed definition incorporates wound complications and drainage management while also being clinically relevant and easy to apply. It may serve as a standardized endpoint for assessing the postoperative course after resection of lower extremity soft tissue tumors.

Glomus tumor mimicking digital adenocarcinoma

Glomus tumors are uncommon, benign lesions commonly located on the digits of the hands and are diagnostically challenging. This is because hemangiomas or ganglion cysts are more commonly identified in those locations. Our case report underlines the diagnostic challenge of a glomus tumor and the importance of immunohistochemical staining.

Percutaneous biopsy of musculoskeletal tumors and the potential for needle tract seeding: technical considerations, current controversies, and outcomes

Multidisciplinary communication and planning between the musculoskeletal radiologist and orthopedic oncologist are essential for proper biopsy planning when a primary musculoskeletal malignancy is suspected. Image-guided percutaneous biopsy allows for real-time visualization of the biopsy needle and surrounding structures, combining high diagnostic accuracy with safety and cost-effectiveness. However, determining a surgically optimal biopsy trajectory for a mass can be technically challenging due to critical surrounding anatomy or challenging needle approach angles. Inappropriately placed biopsies can have serious repercussions on patient function and oncological survival. The potential for needle tract seeding and local recurrence after biopsy of sarcoma has been central to the debate regarding the need for excision of the biopsy tract. This multidisciplinary review highlights current controversies in the field, including the issue of core needle biopsy tracts and their excision, technical considerations and advances in image-guidance in the setting of challenging biopsies, advances in histopathological diagnostics with implications for targeted therapy in sarcoma, as well as surgical and oncological outcomes after needle tract biopsy.

New trends in the surgical management of soft tissue sarcoma: The role of preoperative biopsy

Soft tissue sarcoma (STS) accounts for 1% of all malignant neoplasms in adults. Their diagnosis and management constitute a challenging target. They originate from the mesenchyme, and 50 subtypes with various cytogenetic profiles concerning soft tissue and bones have been recognized. These tumors mainly affect middle-aged adults but may be present at any age. Half of the patients have metastatic disease at the time of diagnosis and require systemic therapy. Tumors above 3-5 cm in size must be suspected of potential malignancy. A thorough history, clinical examination and imaging that must precede biopsy are necessary. Modern imaging techniques include ultrasound, computed tomography (CT), new magnetic resonance imaging (MRI), and positron emission tomography/CT. MRI findings may distinguish low-grade from high-grade STS based on a diagnostic score (tumor heterogeneity, intratumoral and peritumoral enhancement). A score ≥ 2 indicates a high-grade lesion, and a score ≤ 1 indicates a low-grade lesion. For disease staging, abdominal imaging is recommended to detect early abdominal or retroperitoneal metastases. Liquid biopsy by detecting genomic material in serum is a novel diagnostic tool. A preoperative biopsy is necessary for diagnosis, prognosis and optimal planning of surgical intervention. Core needle biopsy is the most indicative and effective. Its correct performance influences surgical management. An unsuccessful biopsy means the dissemination of cancer cells into healthy anatomical structures that ultimately affect resectability and survival. Complete therapeutic excision (R0) with an acceptable resection margin of 1 cm is the method of choice. However, near significant structures, i.e., vessels, nerves, an R2 resection (macroscopic margin involvement) preserving functionality but having a risk of local recurrence can be an acceptable choice, after informing the patient, to prevent an unavoidable amputation. For borderline resectability of the tumor, neoadjuvant chemo/radiotherapy has a place. Likewise, after surgical excision, adjuvant therapy is indicated, but chemotherapy in nonmetastatic disease is still debatable. The five-year survival rate reaches up to 55%. Reresection is considered after positive or uncertain resection margins. Current strategies are based on novel chemotherapeutic agents, improved radiotherapy applications to limit local side effects and targeted biological therapy or immunotherapy, including vaccines. Young age is a risk factor for distant metastasis within 6 mo following primary tumor resection. Neoadjuvant radiotherapy lasting 5-6 wk and surgical resection are indicated for high-grade STS (grade 2 or 3). Wide surgical excision alone may be acceptable for patients older than 70 years. However, locally advanced disease requires a multidisciplinary task of decision-making for amputation or limb salvage.

Two cases of spindle cell tumors with S100 and CD34 co-expression showing novel RAF1 fusions

BACKGROUND

Recently, a novel group of CD34 and S100 co-expression spindle cell tumors with distinctive stromal and perivascular hyalinization harboring recurrent gene fusions involving RET, RAF1, BRAF, and NTRK1/2 gene has been identified.

CASE PRESENTATION

In this study, we reported two Chinese male patients with soft tissue tumors presenting in the right knee joint and the left thigh, respectively. For both patients, the tumors were completely excised with clear margin. Microscopically, case 1showed morphological overlap with neurofibroma, and case 2 showed overlap with lipomatous solitary fibrous tumor. Both tumors showed co-expression of S100 and CD34, and absence of SOX10. Genomic profiling with DNA-based next-generation sequencing (NGS) assay was performed and revealed KIF5B-RAF1 (K16:R8) and TLN2-RAF1 (T54:R8) rearrangements. RNA-based NGS and RT-PCR were performed to confirm the gene fusion.

CONCLUSIONS

Though systemic therapy was not indicated in these two patients, identification of targetable kinase fusions may help to refine tumors with an ambiguous immunoprofile, and provides suggestions for targeted therapy in rare aggressive cases.

Benign Fibrous Histiocytoma of Larynx: A Rare Case Report

The Fibrous histiocytoma is one of the mesenchymal tumors that can present as malignant or benign. We reported a 30 years old male, a rare case of benign fibrous histiocytoma of larynx and evaluated the clinical and histological aspect of this patient.

MRI evaluation of soft tissue tumors: comparison of a fast, isotropic, 3D T2-weighted fat-saturated sequence with a conventional 2D T2-weighted fat-saturated sequence for tumor characteristics, resolution, and acquisition time

OBJECTIVES

To test whether a 4-fold accelerated 3D T2-weighted (T2) CAIPIRINHA SPACE TSE sequence with isotropic voxel size is equivalent to conventional 2DT2 TSE for the evaluation of intrinsic and perilesional soft tissue tumors (STT) characteristics.

METHODS

For 108 patients with histologically-proven STTs, MRI, including 3DT2 (CAIPIRINHA SPACE TSE) and 2DT2 (TSE) sequences, was performed. Two radiologists evaluated each sequence for quality (diagnostic, non-diagnostic), tumor characteristics (heterogeneity, signal intensity, margin), and the presence or absence of cortical involvement, marrow edema, and perilesional edema (PLE); tumor size and PLE extent were measured. Signal-to-noise (SNR) and contrast-to-noise (CNR) ratios and acquisition times for 2DT2 in two planes and 3DT2 sequences were reported. Descriptive statistics and inter-method agreement were reported.

RESULTS

Image quality was diagnostic for all sequences (100% [108/108]). No difference was observed between 3DT2 and 2DT2 tumor characteristics (p < 0.05). There was no difference in mean tumor size (3DT2: 2.9 ± 2.5 cm, 2DT2: 2.8 ± 2.6 cm, p = 0.4) or PLE extent (3DT2:0.5 ± 1.2 cm, 2DT2:0.5 ± 1.0 cm, p = 0.9) between the sequences. There was no difference in the SNR of tumors, marrow, and fat between the sequences, whereas the SNR of muscle was higher (p < 0.05) on 3DT2 than 2DT2. CNR measures on 3DT2 were similar to 2DT2 (p > 0.1). The average acquisition time was shorter for 3DT2 compared with 2DT2 (343 ± 127 s vs 475 ± 162 s, respectively).

CONCLUSION

Isotropic 3DT2 MRI offers higher spatial resolution, faster acquisition times, and equivalent assessments of STT characteristics compared to conventional 2DT2 MRI in two planes. 3DT2 is interchangeable with a 2DT2 sequence in tumor protocols.

KEY POINTS

• Isotropic 3DT2 CAIPIRINHA SPACE TSE offers higher spatial resolution than 2DT2 TSE and is equivalent to 2DT2 TSE for assessments of soft tissue tumor intrinsic and perilesional characteristics. • Multiplanar reformats of 3DT2 CAIPIRINHA SPACE TSE can substitute for 2DT2 TSE acquired in multiple planes, thereby reducing the acquisition time of MRI tumor protocols. • 3DT2 CAIPIRINHA SPACE TSE and 2DT2 TSE had similar CNR of tissues.

Can homogeneous, lipomatous tumors be primarily resected without biopsy? A retrospective analysis of 240 tumors

BACKGROUND

According to guidelines, every soft tissue tumor (STT) larger than 3 cm should be biopsied before definitive resection. Advances in magnetic resonance imaging (MRI) improve the possibility to give a provisional diagnosis of the tumor's entity. Can lipomas and atypical lipomatous tumors (ALTs) of the extremities therefore be primarily marginally resected based on interpretation of MR images without a previous biopsy?.

METHODS

In this retrospective, single-center study, 240 patients with the suspicion of a lipomatous tumor in MRI and surgical treatment in our institution between 2011 and 2020 were included. MR imaging was performed before surgery. All resected specimens underwent histopathological analysis.

RESULTS

The collective comprised 142 tumors that were suspected as lipoma or ALT by the radiologist and underwent primary marginal resection (PMR). One case had myxoid liposarcoma that was underestimated on MRI and needed radical follow-up resection. One-hundred forty-one patients were cured after PMR. Ninety-eight patients were biopsied initially and in 93 cases resected afterwards according to the necessary oncological margins.

CONCLUSION

In our institution, PMR is performed if a lipoma or ALT is suspected on MR imaging. Our treatment method and the diagnostic algorithm are presented. Primary resection spares patients from one surgical procedure, but a slight risk for underestimation of the tumor remains.

Diagnostic delay in soft tissue tumors: a single-center study of a university cancer center with a focus on health services research

Background

Lumps and soft tissue tumors (STT) are frequent reasons for consulting a physician. Most STT are benign, and lumps are not always associated with a tumor. MRI is the most advanced imaging modality to assist a provisional diagnosis of STT. Only a small fraction of STT is malignant, these soft tissue sarcomas are known for their aggressive growth.

The study aims to analyze the influence of the MRI report on the speed of treatment of patients with suspected STT.

Methods

This was a retrospective, longitudinal, single-center study from 2011–2020. We included adult patients who had biopsies or resections of masses suspicious for STT in MRI exams. MRI reports were classified as benign (I), intermediate/unclear (II), or malignant (III). For these cohorts, time was statistically analyzed from MRI scan to first contact with the University cancer center (UCC) and surgery. Furthermore, distance in kilometers from the patients´ home to the UCC was examined and compared to age and suspected malignancy.

Results

Three hundred two patients (♀130; ♂172) were included. Histologic analyses revealed 286 tumors. The average age of the patients was 54.7(SD: 16.2) years. Malignant tumors were more often suspected in older patients (p = 0.0098). Patients with a benign diagnosed tumor in MRI contacted the UCC after an average of 31.3 (SD: 47.8) days. In contrast, patients with suspicion of a malignant tumor contacted the UCC significantly earlier, after 14.1 days (SD: 17.1); p = 0.0098. Likewise, the time between first contact and biopsy/resection was 32.8 days (SD: 35.7) for suspiciously benign tumors, and potentially malignant tumors were treated significantly faster 14.8 (SD: 16.0) days; (p = 0.028). Patients traveled on average 47.5 km (range: 0.5–483) to contact a specialized physician at the UCC. Suspected degree of malignancy or patient´s age had no statistical influence on traveled distance.

Discussion

The treatment speed depended to a great extent on the suspected malignancy of the STT in the MRI report. The provisional diagnoses from the radiologist highly influenced the time delay between MRI scan and first contact to the UCC and surgical treatment. No discrimination of age or distance to the UCC was observed in this study.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-022-07891-w.

[Alveolar rhabdomyosarcoma: Two fusion-negative cases lacking PAX3-FOXO1 and PAX7-FOXO1]

Rhabdomyosarcoma is the most common soft tissue sarcoma in childhood and adolescence. Morphologically, two major forms are described: alveolar and embryonal rhabdomyosarcoma. The former is generally associated with a poorer prognosis and it usually harbors a characteristic fusion gene, PAX3/7-FOXO1, that is used to confirm the diagnosis. We present two cases, both of which exhibited the classic alveolar histology with immunohistochemical myogenic differentiation (Desmin, MYOD-1 and Myogenin expression) and lacked the characteristic fusion gene PAX3/7-FOXO1. The aim of this report is to highlight the importance of the molecular status in the study and diagnosis of these cases, as it seems to be not only a useful diagnostic tool, but also an important prognostic factor.

[Abdominal soft tissue tumors]

Gastrointestinal stromal tumors are the most common mesenchymal tumors in the abdomen and occur in Germany with an incidence of 10 to 15 cases per million inhabitants. Clear identification and characterization are of major importance for the prognosis and therapy of patients. Similarly, they have to be differentiated from other mesenchymal neoplasias such as leiomyomatous, neurogenic, adipocytic, and fibroblastic tumors. Additionally, the number of translocation positive neoplasias is increasing, requiring the use of adequate molecular assays. The aim of this paper is to give practical advice for their identification. Reference pathology is one possibility to support the correct diagnosis.

Update on MR Imaging of Soft Tissue Tumors of Head and Neck

This article reviews soft tissue tumors of the head and neck following the 2020 revision of WHO Classification of Soft Tissue and Bone Tumours. Common soft tissue tumors in the head and neck and tumors are discussed, along with newly added entities to the classification system. Salient clinical and imaging features that may allow for improved diagnostic accuracy or to narrow the imaging differential diagnosis are covered. Advanced imaging techniques are discussed, with a focus on diffusion-weighted and dynamic contrast imaging and their potential to help characterize soft tissue tumors and aid in distinguishing malignant from benign tumors.

What's new in musculoskeletal oncology

We reviewed the recent literature related to primary musculoskeletal tumors and metastatic bone tumors. With regard to primary bone tumors, computer navigation systems and three-dimensional-printed prostheses seem to be new treatment options, especially in challenging anatomical locations, such as the sacrum and pelvis. Regarding the treatment of giant cell tumor of bone, recent studies have suggested that denosumab administration is related to a higher local recurrence rate following curettage, but a lower local recurrence rate following en bloc resection. In addition, there was no difference in the local recurrence rate at five years after surgery between short-term and long-term denosumab therapy. With regard to soft tissue tumors, percutaneous cryoablation appears to be a new treatment option for extra-abdominal desmoid tumors, with encouraging results. Regarding soft tissue sarcomas, a negative surgical margin of < 1 mm is sufficient to control local recurrence. Pexidartinib seems to be a promising systemic therapy for the treatment of tenosynovial giant cell tumors for which surgery is not expected to improve the function of the affected limb. Finally, the life expectancy of patients is the most important factor in determining the optimal surgical procedure for patients with impending or pathological fractures of the long bone due to metastatic bone tumors. Elevated C-reactive protein level was found to be an independent poor prognostic factor at 1 year after surgery for long bone metastases.

The diagnostic performance of conventional ultrasound and strain elastography in malignant soft tissue tumors

OBJECTIVE

To investigate the diagnostic value of conventional ultrasound (US) and strain elastography (SE) in malignant soft tissue tumors.

METHOD

A total of 83 soft tissue masses were included prospectively. US and SE imaging were performed at the same time. Two observers assessed the B mode, color Doppler, elastic scores (ES), strain ratio (SR), and SE size to B mode size (EI/B) ratio and compared the consistency of the data between the observers. According to the pathological diagnosis of resection, the cases were divided into malignant and nonmalignant groups. The diagnostic value of conventional US and SE in the prediction of malignant soft tissue tumors was assessed.

RESULTS

The pathology results divided cases into 36 malignant lesions and 47 nonmalignant lesions. There was no statistically significant difference in gender, location, maximum diameter, echo, tail sign, cystic component, Doppler scores, or SR between the two groups (p > 0.05). However, significant differences between the two groups were found in age, depth, heterogeneity, edge, ES, and EI/B (p < 0.05). The biggest area under the receiver operating characteristics curve (0.934) was the combination model of age, heterogeneity, edge, ES, and EI/B, and the sensitivity and specificity were 0.861 and 0.957, respectively.

CONCLUSIONS

Conventional US and SE are significant for the diagnosis of malignant soft tissue tumors, and SE can be used as a complementary technique to the characterization of STTs using conventional US.

Diagnostic Value of Contrast-Enhanced Ultrasound for Differential Diagnosis of Malignant and Benign Soft Tissue Masses: A Meta-Analysis

This meta-analysis was aimed at investigating the value of using contrast-enhanced ultrasound (CEUS) in the differential diagnosis of benign and malignant soft tissue masses (STMs). Relevant studies published before March 24, 2020 were identified through a comprehensive search of PubMed, Ovid, Cochrane and Web of Science. According to the inclusion criteria, five studies were selected comprising 746 patients. In the differential diagnosis of benign and malignant STMs, the pooled sensitivity and specificity of CEUS were 76% (95% confidence interval [CI]: 71%-81%; heterogeneity [I²] = 74.5%) and 67% (95% CI: 62%-71%; I² = 36.5%), respectively. The diagnostic odds ratio was 7.37 (95% CI: 3.78%-14.35; I² = 66.6%). The overall area under the curve was 0.77 (standard error: 0.0392). Subgroup analysis revealed that different index tests of CEUS resulted in different diagnostic performance. Importantly, CEUS is an effective method for the differential diagnosis between benign and malignant STMs.

Diagnostic limitations and considerations in the imaging evaluation of advanced multicentric infantile myofibromatosis

Infantile myofibromatosis, the most common fibrous tumor of infancy, is classified in 2 forms; as a solitary nodule or as numerous, widely-distributed multicentric lesions with or without visceral involvement. Although benign, multicentric myofibromas are still associated with a high incidence of morbidity and mortality due to the infiltration of critical structures. Herein, we present a case of an infant with aggressive PDGFRB and NOTCH3 mutation-negative myofibromas distributed throughout the vascular, respiratory, and gastrointestinal systems. The extensive disease resulted in pulmonary hypertension, respiratory failure and gastrointestinal obstruction refractory to chemotherapy and unamenable to surgical resection. Despite the presence of numerous highly invasive myofibromas, multiple imaging modalities largely underestimated, or even missed, tumors found at autopsy. This case demonstrates the limitations of radiographic imaging to assess disease burden in multicentric infantile myofibromatosis. The postmortem findings of extensive disease far exceeding what was demonstrated by multiple imaging modalities suggests that pediatricians should have a high index of suspicion for undetected tumors if clinical deterioration is otherwise unexplained.

Mesenchymal lesions of the vulva

Mesenchymal lesions of the vulva include site-specific entities limited to the lower genital tract, as well as a range of non-site-specific tumors that are more common at extragenital sites. Site-specific lesions include fibroepithelial stromal polyp, cellular angiofibroma, angiomyofibroblastoma, and aggressive angiomyxoma. Non-site-specific tumors that may occur in the vulva include those of smooth muscle, skeletal muscle, vascular, neural, adipocytic, and uncertain differentiation. This review discusses both site-specific and non-site-specific vulvar mesenchymal lesions including non-neoplastic proliferations, benign neoplasms, locally aggressive neoplasms with a predilection for local recurrence, neoplasms of indeterminate biologic potential, and frankly malignant neoplasms with a high risk of distant metastasis and death. Accurate diagnosis is essential for proper management, and is facilitated by correlation with clinical findings and targeted application of immunohistochemical and molecular studies.

Use of Free Anterolateral Thigh Flap in Reconstruction of Soft Tissue Defects in Orthopedic Oncology: What are the Outcomes?

INTRODUCTION

Soft tissue defects due to trauma with crush injuries and post-tumor excision are large in size. Free anterolateral flap provides a stable and durable coverage of soft tissue defects and leads to good functional outcomes.

MATERIALS AND METHODS

Between January 2017 and January 2019, eight males and six female patients with soft tissue defects were operated upon using a free anterolateral thigh flaps. The defects in ten patients were due to post-tumor extirpation and in four patients due to wound breakdown following post-tumor extirpation.

RESULTS

The average flap dimension was 14 cm × 12 cm. The mean follow-up was 11 months (4-28 months). All the flaps survived well except in one patient who with an upper limb defect, had flap necrosis owing to which patient needed to undergo abdominal flap coverage. Two patients with sarcoma developed local recurrence and had to undergo above‑knee amputation.

CONCLUSION

The method of reconstruction depends on the size of defect and area to be covered and need of post-surgery mobilization and need for radiotherapy. The free anterolateral thigh flap has varied uses in orthopedics with very good extent of coverage and provides very potent coverage of neurovascular structures, bones, tendons, and implants.

Dermatofibrosarcoma protuberans: a tumor in the wide spectrum of the bland-looking spindle cell lesions of the breast

Dermatofibrosarcoma protuberans (DFSP) is a soft tissue tumor, usually occurring as a cutaneous lesion localized to the trunk or extremities; although it has a high rate of local recurrence, its metastatic potential is very low and complete surgical excision is frequently curative. Most of the cases reported as “DFSP of the breast” are tumors arising in the subcutaneous tissue infiltrating the underlying breast parenchyma. To the best of our knowledge, only 5 cases of DFSP of the breast have been reported to date. We herein present a rare case of DFSP of the breast parenchyma in a 41-year-old female with emphasis on the diagnostic clues and the differential diagnosis with other benign and malignant spindle cell lesions of the breast.

A Juxta-Articular Myxoma of the Thumb

Juxta-articular myxomata are benign tumors that are mostly encountered in the vicinity of larger joints. Few cases in the hand have been reported. We present a case of a juxta-articular myxoma at the metacarpophalangeal joint of the thumb in a 40-year-old man. The preoperative diagnostic work-up included 4-dimensional magnetic resonance angiography and ultrasound. The histochemical examination of the resected tumor established the diagnosis definitively. Follow-up magnetic resonance imaging scheduled with no clinical suspicion of tumor recurrence 9 months after surgery revealed no obvious recurrence. At 14 months, the patient had full motion without pain and declined further imaging.

Mesenchymal neoplasms: Is it time for cytology? New perspectives for the pre-operative diagnosis of soft tissue tumors in the molecular era

Soft tissue tumors comprise a great variety of common and rare entities with overlapping features. Their diagnosis is based on the evaluation of several histological parameters which are difficult to assess on small incisional biopsies. Useful diagnostic markers in the field of soft tissue tumors include: 1) molecular biomarkers detecting pathogenetically relevant, distinctive alterations; 2) immunohistochemical surrogate biomarkers of pathogenetically relevant, distinctive molecular alterations; 3) highly specific immunohistochemical biomarkers indicating tumor differentiation. Their introduction in clinical practice has revolutionized the pre-operative diagnosis of soft tissue tumors. Cytology has long been considered inadequate as a first-line approach in this setting. However, since the implementation of new immunohistochemical and molecular tests with high diagnostic specificity, fine needle aspiration cytology (FNAC) is starting to gain acceptance for the pre-operative assessment of soft tissue tumors. FNAC represents a versatile, poorly expensive and well-tolerated diagnostic strategy with relevant advantages over histological biopsies. Moreover, evidences suggest that, in expert hands, FNAC can also aim at a definite diagnosis, especially if a cell block is prepared, allowing the application of multiple ancillary techniques.

Soft Tissue Special Issue: Fibroblastic and Myofibroblastic Neoplasms of the Head and Neck

Fibroblastic and myofibroblastic neoplasms of the head and neck encompass a group of rare tumor types with often overlapping clinicopathologic features that range in biologic potential from benign to overtly malignant. Even neoplasms with no metastatic potential may provide significant therapeutic challenges in this region due to the unique anatomy of the head and neck. This review will cover the following entities, highlighting important clinical aspects of each neoplasm and then focusing on their characteristic histomorphology, immunophenotype, and molecular alterations: nodular and cranial fasciitis, fibrous hamartoma of infancy, nasopharyngeal angiofibroma, nuchal-type and Gardner fibromas, desmoid fibromatosis, dermatofibrosarcoma protuberans and giant cell fibroblastoma, solitary fibrous tumor, inflammatory myofibroblastic tumor, low-grade myofibroblastic sarcoma, infantile fibrosarcoma, low-grade fibromyxoid sarcoma, and sclerosing epithelioid fibrosarcoma. While some of these neoplasms characteristically arise in the head and neck, others are rarely described in this anatomic region and may therefore be particularly difficult to recognize. Distinction between these entities, however, is crucial, particularly as the molecular pathogenetic basis for these neoplasms are being rapidly elucidated, in some instances allowing for targeted therapeutic approaches.

Clinical Applications of DSC-MRI Parameters Assess Angiogenesis and Differentiate Malignant From Benign Soft Tissue Tumors in Limbs

OBJECTIVE

To investigate the correlation between dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) parameters and angiogenesis and to explore prospectively the feasibility of using DSC-MRI to differentiate malignant from benign soft tissue tumors (STTs) in limbs.

METHODS

This prospective study included 33 patients with STTs in limbs who underwent DSC-MRI after bolus Gd-DTPA infusion. All STTs were confirmed by pathological examination after surgery and microvessel density (MVD), vascular endothelial growth factor (VEGF) expression, were evaluated by immune-histochemical analysis. Semiquantitative DSC-MRI parameters, including negative enhancement integral (NEI), maximum slopes of decrease (MSD) and increase (MSI), and mean time to enhancement were calculated by postprocessing in workstation. The correlation was analyzed between DSC-MRI parameters and angiogenesis factors. Then, the DSC-MRI parameters were compared between benign and malignant STTs and evaluated for diagnostic efficiency by receiver operating characteristic.

RESULTS

The 33 evaluated tumors were consisted of 13 benign and 20 malignant STTs in limbs. Significant positive correlations were observed between NEI, MSD, MSI and MVD, VEGF (p < 0.05). However, mean time to enhancement had no correlation with MVD and VEGF. The benign and malignant STTs differed significantly in terms of NEI, MSD, and MSI (p < 0.05). The areas under the curve (AUC) of NEI, MSD, and MSI were 0.915, 0.862, and 0.815 for discriminating between benign and malignant STTs, respectively.

CONCLUSION

DSC-MRI parameters are positively correlated with MVD and VEGF, which can evaluate angiogenesis indirectly. Furthermore, DSC-MRI can be considered as one of assistant noninvasive MR imaging technique in differentiation between benign and malignant STTs in limbs.

Musculoskeletal Tumors

Pediatric musculoskeletal tumors can arise in both bone and soft tissues. The overwhelming majority of these are benign; however, rarely, malignant neoplasms do occur. These are collectively termed sarcomas, indicating their mesenchymal origin. Sarcoma management requires careful adherence to the well-described tenets of tumor management. This article summarizes the basic principles and recent advances in the management of soft tissue and bone tumors.

Update on selected advances in the immunohistochemical and molecular genetic analysis of soft tissue tumors

Although traditional morphological evaluation remains the cornerstone for the diagnosis of soft tissue tumors, ancillary diagnostic modalities such as immunohistochemistry and molecular genetic analysis are of ever-increasing importance in this field. New insights into the molecular pathogenesis of soft tissue tumors, often obtained from high-throughput sequencing technologies, has enabled significant progress in the characterization and biologic stratification of mesenchymal neoplasms, expanding the spectrum of immunohistochemical tests (often aimed towards recently discovered genetic events) and molecular genetic assays (most often fluorescence in situ hybridization and reverse transcription-polymerase chain reaction). This review discusses selected novel molecular and immunohistochemical assays with diagnostic applicability in mesenchymal neoplasms, with emphasis on diagnosis, refinement of tumor classification, and treatment stratification.

Conformity to Clinical Practice Guidelines at Initial Management in Adult Soft Tissue and Visceral Tumors since the Implementation of the NetSarc Network in Eastern France

BACKGROUND

Soft tissue sarcomas are rare and heterogenous tumors that are hard to diagnose. The aim of this study was to evaluate local practices and conformity to clinical practice guidelines (CPGs) for their initial diagnostic management.

MATERIALS AND METHODS

Patients were carriers of a soft tissue or visceral tumor, presented at a sarcoma tumor board (STB) between 2010 and 2016. Conformity to CPGs was evaluated using ten criteria designed for this purpose. Associations between different factors and conformity to composite criteria, reflecting the three main diagnostic steps (imaging, biopsy and histological report) were analyzed.

RESULTS

A total of 643 patients were included. A preoperative tumor imaging assessment and a biopsy were performed according to CPGs in 80.8% and 36.8% of the cases, respectively. When done, the first surgical resection was R0 in 30.3% of cases, R1 in 28.6%, and R2 in 10.9%. The rest of the operated patients with sarcoma had a second surgical excision (11.4%), an intraoperative fragmentation (4.3%), or margins were unknown (14.4%). Six of the ten quality criteria presented a conformity rate higher than 70%. Two criteria with a conformity rate lower than 20% were the most controversial: presentation at a STB before biopsy and freezing of a tumor fragment. A multivariate analysis revealed that the common predictor of nonconformity to composite criteria was the initial management in a nonexpert center.

CONCLUSION

Initial diagnostic management requires improvement, especially outside of specialized centers.

IMPLICATIONS FOR PRACTICE

This article supports the essential need to refer patients with soft tissue tumors to specialized centers to improve the management of sarcomas beginning at the diagnostic phase. Indeed, the reported data were very similar to those already described at the national level of the NetSarc network and indicate the necessity to keep raising awareness about this simple issue: early referral to reference centers will save lives.

Exosomes in sarcomas: Tiny messengers with broad implications in diagnosis, surveillance, prognosis and treatment

Exosomes are cell-secreted extracellular vesicles, which contain an array of biomolecules, such as proteins, mRNAs, microRNAs, and lipids, take part in intercellular communication and mediate tumor-host interactions. They are increasingly considered as a source of biomarkers for liquid biopsies as well as potential drug vectors. Sarcomas are rare malignant mesenchymal tumours and due to their relative rarity exosomes have not been investigated in as extensively as in epithelial malignancies. Nonetheless, valuable information has been gathered over the last years on the roles of exosomes in sarcomas. In the present review we summarize all relevant data obtained so far from cell lines, animal models and patients with emphasis on their potential clinical utility.

Advanced magnetic resonance imaging (MRI) of soft tissue tumors: techniques and applications

Imaging evaluation of soft tissue tumors is important for the diagnosis, staging, and follow-up. Magnetic resonance imaging (MRI) is the preferred imaging modality due to its multiplanarity and optimal tissue contrast resolution. However, standard morphological sequences are often not sufficient to characterize the exact nature of the lesion, addressing the patient to an invasive bioptic examination for the definitive diagnosis. The recent technological advances with the development of functional MRI modalities such as diffusion-weighted imaging, dynamic contrast-enhanced perfusion imaging, magnetic resonance spectroscopy, and diffusion tensor imaging with tractography have implemented the multiparametricity of MR to evaluate in a noninvasive manner the biochemical, structural, and metabolic features of tumor tissues. The purpose of this article is to review the state of the art of these advanced MRI techniques, with focus on their technique and clinical application.

Pleomorphic liposarcoma: Updates and current differential diagnosis

Pleomorphic liposarcoma is the least common but most aggressive subtype of liposarcoma. Tumors most commonly arise in the deep soft tissues of the extremities in adult patients. Pleomorphic liposarcoma has no specific immunohistochemical or molecular genetic features, and the presence of lipoblasts remains the sole diagnostic criterion. Diagnostic challenges include the identification of lipoblasts, which are often scarce or focal, and the distinction from other pleomorphic sarcomas, including dedifferentiated liposarcoma with homologous lipoblastic differentiation. This review provides an updated overview of the clinicopathologic features of pleomorphic liposarcoma, with discussion of its morphologic variants, differential diagnosis, and the role of small biopsy samples.

Mesenchymal Neoplasms of the Genitourinary System: A Selected Review with Recent Advances in Clinical, Diagnostic, and Molecular Findings

Mesenchymal neoplasms of the genitourinary (GU) tract often pose considerable diagnostic challenges due to their wide morphologic spectrum, relative rarity, and unexpected incidence at GU sites. Soft tissue tumors arise throughout the GU tract, whether from adventitia surrounding or connective tissues within the kidneys, urinary bladder, and male and female genital organs. This selected article focuses on a subset of these lesions, ranging from benign to malignant and encompassing a range of patterns of mesenchymal differentiation, where recent scholarship has lent greater insight into their clinical, molecular, or diagnostic features.

The epidemiology and survivorship of clear cell sarcoma: a National Cancer Database (NCDB) review

PURPOSE

Clear cell sarcoma (CCS) is a rare soft tissue tumor thought to originate from tendons and aponeuroses. This is the largest and most comprehensive study of CCS to the best of our knowledge. In addition, this is the first study to determine the estimated 10-year overall survival, specific treatment modalities including neoadjuvant and adjuvant combinations, and sites of distant metastasis in CCS utilizing a national database.

METHODS

The National Cancer Database (NCDB) was used to study 489 patients diagnosed with CCS from 2004 to 2014. Kaplan-Meier methods were used to estimate 5- and 10-year overall survival, and log-rank tests were used to compare survival amongst stage.

RESULTS

Median age at diagnosis was 39 years. Males and females were equally affected. Race distribution was 78% Caucasian and 15% Black. Most common primary site was lower limb or hip (53%). Percentage of patients with distant organ metastases was 15%, with lung being the most common site (4%). Median overall survival was 57.2 months. Overall estimated 5- and 10-year survival was approximately 50 and 38%, respectively. Approximate 5-year survival for Stages I-IV was 75, 65, 35, and 15%, respectively. Stages at disease presentation were 34% at Stage I, 13% at Stage II, 16% at Stage III, and 38% at Stage IV. Surgery was the most common form of treatment (83%); 34% received radiation and 20% received chemotherapy.

CONCLUSION

The 5-year overall survival for CCS in Stages III and IV was much worse than Stages I and II. Overall estimated 5- and 10-year survival was approximately 50 and 38%, respectively. Men and women were equally affected and had a median age at diagnosis of 39 years. The most common tumor location was lower limb and hip and the most common site of metastases was the lung.

Stem cell transcription factor SOX2 in synovial sarcoma and other soft tissue tumors

BACKGROUND

SOX2 has gained considerable interest as a pluripotency inducing gene. Co-transfection of SOX2 together with NANOG, KLF4 and c-MYC into adult fibroblasts was able to generate pluripotent stem cells. SOX2 has been reported to be expressed in synovial sarcoma, a tumor being characterized by the SS18-SSX gene fusion forming part of the SWI/SNF chromatin remodeling complex that affects histone methylation. The role of SOX2 in this tumor type as well as other soft tissue tumor entities however is still poorly characterized. We analyzed SOX2 protein expression in soft tissue tumors. Alongside we tested Histone H3 expression (H3K27me3) in SOX2 positive cases to investigate this epigenetic mark and its correlation with the SOX2 status and clinicopathological parameters.

METHODOLOGY

In total, 60 samples of synovial sarcomas from the reference center for soft tissue tumors at the institute of pathology of the Jena University hospital were included into the study along with 343 other tissue tumors. Protein analysis was done by immunohistochemistry of tissue microarrays. All synovial sarcoma cases were confirmed by molecular testing using SS18 FISH break apart probes.

RESULTS

SOX2 reactivity was detectable in 35 synovial sarcoma cases (58.3%) while 25 (41.7%) were negative. Only 13 cases of the other 343 soft tissue tumors, varying from nodular fasciitis to undifferentiated pleomorphic sarcoma, revealed a SOX2 expression, 12 out of these were undifferentiated high grade sarcoma. There was no obvious correlation with the clinicopathological data. H3K27me3 immunohistochemistry of the synovial sarcoma cases revealed a high statistically significant correlation between SOX2 and H3K27me3 expression (p < 0,0005, Chi square test). Similar to SOX2, there was no correlation between H3K27me3 expression and tumor grade. Six SOX2 positive synovial sarcoma cases were analyzed by FISH using a SOX2/CEN3 dual color FISH probe. None of these cases revealed an amplification of the SOX2 gene.

CONCLUSION

The data confirms previous studies reporting SOX2 and H3K27me3 expression in synovial sarcoma and reveals that both biomarkers are related to each other. It strengthens the notion that the tumor type is driven by epigenetic processes similar to those that are operating in pluripotent stem cells. The relevance of these parameters in the pathway pathology of synovial sarcoma, i.e. the timing and dosing of SOX2 and H3K27me3 expression initiated by the SS18-SSX driver mutation together with the interplay of these events with other signaling pathways, cellular mechanisms and additional mutations in tumor progression, will require further studies.

Correlation between histological and ultrasonographic findings of soft tissue tumors: To verify the possibility of cell-like resolution in ultrasonography

BACKGROUND

The purpose of this study is to test the possibility of obtained cell-like resolution in soft tissue tumors on the basis of ultrasound echotexture.

METHODS

This is a prospective study consisting of 57 patients (29 females and 28 males, age range: 9-83 years, average age: 44.5 years) with palpable soft tissue mass, referred from the Departments of Orthopedics and Oncology for ultrasound (US)-guided biopsy. The study was approved by the institutional review board (IRB) of our hospital. Ultrasonographic images were recorded by still imaging in the biopsy tract in each biopsy session. Equipment included curvilinear and linear array probes. After biopsy, a radiologist and a pathologist correlated the US image and the observations regarding the histology of the tissue specimen in low-power (40 × magnification) and high-power (100-400 × magnification) fields.

RESULTS

The histologic results included 22 benign and 35 malignant lesions. The echotexture of the soft tissue tumors correlated well with the cellular distribution and arrangement: the greater the number of cells and the more regular their arrangement as seen histologically, the greater is the hypoechogenicity on the ultrasound. The echogenicity of the soft tissue tumor also correlated well with the presence of fat cells, hemorrhage, cartilage, and osteoid tissue, all of which cause an increase in echogenicity.

CONCLUSION

This study showed that the echotexture of soft tissue tumors can predict some details of cellular histology.

Lipoblastoma of the Labia: A Case Report

BACKGROUND

Vulvar masses are rare in prepubertal girls. Lipoblastomas are benign adipose tumors that arise from embryonic white fat and occur almost exclusively in infants and children.

CASE

An 18-month-old female infant presented with a 2-cm mobile mass in the left labia majora. Imaging and examination revealed normal prepubertal gynecologic structures and a 4.5 cm fatty mass in the left labia. Surgical excision revealed a 3.8 cm well circumscribed adipose tissue mass consistent with maturing lipoblastoma on microscopic examination. Cytogenetic analysis revealed 79,XXX [7]/46,XX[13], a near-triploid clone.

SUMMARY AND CONCLUSION

The differential diagnosis of vulvar masses in children should include lipoblastoma. Although preoperative imaging has limited ability to differentiate lipomatous tumors, magnetic resonance imaging is the modality of choice for evaluating tumor extension and for surgical planning. Treatment is complete surgical excision with close follow-up for at least 5 years because of the high recurrence rate.

Pseudolipoblastic perineurioma: an unusual morphological variant of perineurioma that may simulate liposarcoma

Perineuriomas are rare peripheral nerve sheath tumors arising from or differentiating along the lines of normal perineurial cells. They can be divided into intraneural and soft tissue types, with the latter category including a significant number of morphological variants. Herein, we further expand their morphological spectrum to include "pseudolipoblastic" perineuriomas. These lesions occurred in the tongue of a 30-year-old man and in the triceps of a 67-year-old woman and were characterized by bland, epithelioid cells with striking intracytoplasmic vacuolization. The architecture varied, with some areas showing a striking "net-like" or "microreticular" pattern and smaller areas having a more typical spindled and whorled appearance. Clinical follow-up (5months and 52months, respectively) showed no evidence of local recurrence or metastasis. Multiple perineurial markers, including epithelial membrane antigen, claudin-1, GLUT-1, and collagen IV, were diffusely positive. Both cases were submitted in consultation out of concern that they represented high-grade liposarcomas. To the best of our knowledge, this unusual morphological variant of perineurioma has not been reported. These tumors appear to be entirely benign and should be cured with simple excision. Pseudolipoblastic perineuriomas should be distinguished from round cell and epithelioid pleomorphic liposarcomas, as well as from other tumors that may show prominent intracytoplasmic vacuolization.

Pleomorphic hyalinizing angiectatic tumor arising in the groin: A case report

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Pleomorphic Hyalinizing Angiectatic Tumors are rare tumors.

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Diagnosis is best with microscopic and histochemical analysis.

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Treatment is with wide local resection.

Introduction

Pleomorphic hyalinizing angiectatic tumors are a rare group of tumors that are currently classified as benign tumors of unknown differentiation. To our knowledge, less than 100 cases have been reported in literature. We report a case that presented in the groin – an uncommon location for this rare tumor.

Case report

A 75 year-old female presented with a seven-year history of painless right groin mass with rapid growth of 2 year duration. On physical examination, a firm and mobile mass was identified in the right groin. It measured 12 cm × 8 cm, with no clinically palpable lymph nodes. Microscopic and immunohistochemical features were consistent with pleomorphic hyalinizing angiectatic tumor.

Discussion

Pleomorphic hyalinizing angiectatic tumor is a rare soft tissue tumor usually diagnosed using microscopic and immuohistochemical analysis to allow for differentiation from other soft tissue tumors. It is treated by wide local excision.

Primary Soft Tissue Lymphomas: Description of Seven Cases and Review of the Literature

The present study describes a series of primary soft tissue lymphomas, including immunohistochemical characterization by tissue microarray and cytogenetic profiling. Formalin-fixed, paraffin-embedded tissue samples were collected from patients who underwent soft tissue biopsy. Cases were selected according to the definition of primary soft tissue lymphoma as a lymphoid malignancy arising in soft tissues without evidence of other nodal or extranodal localization for a period of at least 6 months. Our series comprised seven patients with a mean age of 72 years. There were three diffuse large B-cell lymphomas (DLBCLs); one B-cell lymphoma, unclassifiable, with features intermediate between DLBCL and Burkitt lymphoma; one DLBCL derived from follicular lymphoma; one ALK-negative anaplastic large cell lymphoma; and one follicular lymphoma. Immunohistochemical and molecular profiles were consistent with the histological diagnoses. The present study contributes to our knowledge about uncommon presentation of lymphoid neoplasms and confirms previously published clinical-pathological data. We present, for the first time, the complete immunohistochemical profile and molecular cytogenetic studies of these lymphoid neoplasms. A rare case of a primary soft tissue ALK-negative anaplastic large cell lymphoma is described in detail.

Cutaneous syncytial myoepithelioma:: Clinico-pathological features and differential diagnosis

Cutaneous syncytial myoepithelioma (CSM) is a very rare tumor belonging to the spectrum of skin myoepithelial lesions. CSM usually affects the upper extremities of young to middle aged patients and is characterized by peculiar morphological and immunohistochemical features. Unlike classic myoepithelioma, CSM is composed by a densely packed proliferation of spindled to histiocytoid cells, which are variably positive for EMA, S100, SMA, and frequently negative for cytokeratins and GFAP. The peculiar histopathology and the extreme rarity of such lesion (less than 40 cases reported in the literature) can make the diagnosis of CSM a true challenge. In the present case, we report the clinico-pathological features of a primary CSM occurring in a 38 year-old Caucasian man. The differential diagnoses of such lesion are also briefly discussed.

Certainty of S100 from Physiology to Pathology

S100 exists in wide variety of tissues and cell types, originally isolated from brain tissue and they are of low molecular weight proteins. S100 is evenly distributed in cytoplasm and also in nucleoplasm and is involved in both intercellular and extracellular functions. S100 protein is generally expressed in normal and also in pathological conditions. In current review, we discuss: a) update nomenclature of the various S100 proteins, b) expression of S100 in oral diseases (different soft tissue tumors, odontogenic cyst and tumor) for diagnostic value and also to know their histogenesis, c) role of S100 and RAGE receptor in oral squamous cell carcinoma.

Assessing the role of ¹⁸F-FDG PET and ¹⁸F-FDG PET/CT in the diagnosis of soft tissue musculoskeletal malignancies: a systematic review and meta-analysis

PURPOSE

Twelve years ago a meta-analysis evaluated the diagnostic performance of (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in assessing musculoskeletal soft tissue lesions (MsSTL). Currently, PET/CT has substituted PET imaging; however, there has not been any published meta-analysis on the use of PET/CT or a comparison of PET/CT with PET in the diagnosis of MsSTL. Therefore, we conducted a meta-analysis to identify the current diagnostic performance of (18)F-FDG PET/CT and determine if there is added value when compared to PET.

METHODS

A systematic review of English articles was conducted, and MEDLINE PubMed, the Cochrane Library, and Embase were searched from 1996 to March 2015. Studies exploring the diagnostic accuracy of (18)F-FDG PET/CT (or dedicated PET) compared to histopathology in patients with MsSTL undergoing investigation for malignancy were included.

RESULTS

Our meta-analysis included 14 articles composed of 755 patients with 757 soft tissue lesions. There were 451 (60 %) malignant tumors and 306 benign lesions. The (18)F-FDG PET/CT (and dedicated PET) mean sensitivity, specificity, accuracy, positive predictive value, and negative predictive value for diagnosing MsSTL were 0.96 (0.90, 1.00), 0.77 (0.67, 0.86), 0.88 (0.85, 0.91), 0.86 (0.78, 0.94), and 0.91 (0.83, 0.99), respectively. The posterior mean (95 % highest posterior density interval) for the AUC was 0.92 (0.88, 0.96). PET/CT had higher specificity, accuracy, and positive predictive value when compared to a dedicated PET (0.85, 0.89, and 0.91 vs 0.71, 0.85, and 0.82, respectively).

CONCLUSION

(18)F-FDG PET/CT and dedicated PET are both highly accurate in the diagnosis of MsSTL. PET/CT is more accurate and specific and has a higher positive predictive value than PET.

An unusual case of neurothekeoma of the arm in an adult

Neurothekeomas are uncommon benign neoplasms with a peripheral nerve sheath origin. This tumor usually involves dermis and is described as a small, solitary, slow growing and reddish to flesh-colored nodule or papule. Neurothekeoma preferentially affects the central aspect of the face, the arms or shoulders of women in the second and third decades of life. This is the first case report of neurothekeoma involving the wrist developing from synovial tissue and with uncertain clinical behavior in an adult female. The tumor was completely excised under brachial plexus block. Histopathologically, the examination of the microscopic slides revealed the presence of a 20-mm diameter, well-circumscribed and multilobulated tumor composed of abundant myxoid stroma with cellular elements; with immunohistochemistry there was positivity to vimentin but S100-protein, epithelial membrane antigen, cytokeratin AE1-3, CD99 and CD34 were all negative. This pattern suggested a myxoid tumor form of neurothekeoma, mixed subtype. The patient had an atypical local recurrence and was re-operated after 3 months. After 12 months there was no evidence of clinical recurrences confirmed by magnetic resonance evaluation. Basically, our case report adds an important element in the correct clinical management of neurotecheomas: faced with a histological diagnosis with an unusual localization and mixed or hypercellular type, clinicians must consider the possibility of an early local recurrence, suggesting a close clinical and radiological follow-up.

Assessment of Musculoskeletal Malignancies with Functional MR Imaging. Magn Reson Imaging Clin N Am. 2016;24:239-259. [PMID: 26613884 DOI: 10.1016/j.mric.2015.08.006]

Functional MR imaging is the technique of choice to evaluate and manage malignant musculoskeletal masses. Advanced MR imaging sequences include chemical shift MR imaging, diffusion-weighted imaging with apparent diffusion coefficient mapping, MR spectroscopy imaging, and dynamic contrast-enhanced perfusion imaging. Functional MR imaging adds value to morphologic sequences in the detection, characterization, staging, and posttherapy assessment of malignant musculoskeletal malignancies. This article reviews the technical role of each functional sequence and their clinical applications to allow more confident decisions to be made. Multiparametric analysis of functional and anatomic MR sequences allows musculoskeletal tumors analysis to be improved.

Soft tissue tumors of the sinonasal tract

Primary soft tissue tumors arising in the sinonasal tract are rare. While many mesenchymal neoplasms have been reported in the nasal cavity, sinuses, and nasopharynx, few are distinctive to this anatomic region. Some tumor types are relatively more common in this area, such as schwannoma and rhabdomyosarcoma. Nasopharyngeal angiofibroma and sinonasal hemangiopericytoma are unique entities of the sinonasal tract, as well as the recently characterized biphenotypic sinonasal sarcoma. This review discusses the clinical, morphologic, and immunohistochemical features and currently known molecular data of the more frequently encountered soft tissue tumors of the sinonasal tract.

Schwannoma located in the upper gingival mucosa: case report and literature review

The Schwannoma is a benign tumor that originates from Schwann cells of peripheral motor and sensory nerves. It presents as a solitary, slow growing, smooth-surfaced and asymptomatic firm mass. The pre-operative diagnosis is often difficult, and in majority of cases it can only be made during the surgery and the definitive diagnosis obtained by histological study when cells test positive for S-100 protein. In this report, a case of a 20-year-old female patient with a Schwannoma located in the upper gingival mucosa is discussed. The patient was referred to the department of oral and maxillofacial surgery with chief complaint of enlargement of the upper gingival mucosa at the level of upper right premolar. Clinical findings showed characteristics of connective tissue tumor including epulis; however, histologic and immunohistochemical studies revealed it to be a Schwannoma. There has been no sign of recurrence 1 year and 8 months after surgery.