MRI features of benign peripheral nerve sheath tumors: how do sporadic and syndromic tumors differ?

OBJECTIVES

To compare MRI features of sporadic and neurofibromatosis syndrome-related localized schwannomas and neurofibromas.

METHODS

In this retrospective study, our pathology database was searched for "neurofibroma" or "schwannoma" from 2014 to 2019. Exclusion criteria were lack of available MRI and intradural or plexiform tumors. Qualitative and quantitative anatomic (location, size, relationship to nerve, signal, muscle denervation) and functional (arterial enhancement, apparent diffusion-weighted coefficient) MRI features of sporadic and syndrome-related tumors were compared. Statistical significance was assumed for p < 0.05.

RESULTS

A total of 80 patients with 64 schwannomas (sporadic: 42 (65.6%) v. syndrome-related: 22 (34.4%)) and 19 neurofibromas (sporadic: 7 (36.8%) v. syndrome-related: 12 (41.7%)) were included. Only signal heterogeneity (T2W p=0.001, post-contrast p=0.03) and a diffused-weighted imaging target sign (p=0.04) were more frequent with schwannomas than neurofibromas. Sporadic schwannomas were similar in size to syndrome-related schwannomas (2.9±1.2cm vs. 3.7±3.2 cm, p = 0.6), but with greater heterogeneity (T2W p = 0.02, post-contrast p = 0.01). Sporadic neurofibromas were larger (4.6±1.5cm vs. 3.4±2.4 cm, p = 0.03) than syndrome-related neurofibromas, also with greater heterogeneity (T2W p=0.03, post-contrast p=0.04). Additional tumors along an affected nerve were only observed with syndrome-related tumors). There was no difference in apparent diffusion coefficient values or presence of early perfusion between sporadic and syndrome-related tumors (p > 0.05).

CONCLUSIONS

Although syndrome-related and sporadic schwannomas and neurofibromas overlap in their anatomic, diffusion and perfusion features, signal heterogeneity and presence of multiple lesions along a nerve are differentiating characteristics of syndrome-related tumors.

Malignant Chest Wall Tumors: Complex Defects and Their Management-A Review of 181 Cases

BACKGROUND

Chest wall tumors are a heterogeneous group of tumors that are managed by surgeons from diverse specialties. Due to their rarity, there is no consensus on their diagnosis and management.

MATERIALS

This retrospective, descriptive analysis includes patients with malignant chest wall tumors undergoing chest wall resection. Tumors were classified as primary, secondary, and metastatic tumors. The analysis includes clinicopathological characteristics, resection-reconstruction profile, and relapse patterns.

RESULTS

A total of 181 patients underwent chest wall resection between 1999 and 2020. In primary tumors (69%), the majority were soft tissue tumors (59%). In secondary tumors, the majority were from the breast (45%) and lung (42%). Twenty-five percent of patients received neoadjuvant chemotherapy, and 98% of patients underwent R0 resection. Soft tissue, skeletal + soft tissue, and extended resections were performed in 45%, 70%, and 28% of patients, respectively. The majority of patients (60%) underwent rib resections, and a median of 3.5 ribs were resected. The mean defect size was 24 cm2. Soft tissue reconstruction was performed in 40% of patients, mostly with latissimus dorsi flaps. Rigid reconstruction was performed in 57% of patients, and 18% underwent mesh-bone cement sandwich technique reconstruction. Adjuvant radiotherapy and chemotherapy were given to 29% and 39% of patients, respectively.

CONCLUSIONS

This is one of the largest single-institutional experiences on malignant chest wall tumors. The results highlight varied tumor spectra and multimodality approaches for optimal functional and survival outcomes. In limited resource setting, surgery, including reconstructive expertise, is very crucial.

Solitary plexiform neurofibroma of the tongue: report of a case with no evidence of neurofibromatosis type 1

Neurofibromas are frequently present in the skin, but are uncommon in the oral and maxillofacial region. There are three histological variants of neurofibroma: localized, diffuse, and plexiform. The plexiform histological variant of neurofibroma is the least common and is a rare occurrence in the oral cavity. Furthermore, plexiform neurofibroma is usually pathognomonic of neurofibromatosis type 1. A case of solitary plexiform neurofibroma of the tongue with no evidence of neurofibromatosis in a 50-year-old female Chinese patient is reported here. The lesion presented as a single, large, well-circumscribed rounded mass in the left hemi-tongue. The tumour was completely excised. No recurrence was observed at the 6-month follow-up.

Diagnostic conundrums of schwannomas: two cases highlighting morphological extremes and diagnostic challenges in biopsy specimens of soft tissue tumors

Schwannomas are benign, slow-growing peripheral nerve sheath tumors commonly occurring in the head, neck, and flexor regions of the extremities. Although most schwannomas are easily diagnosable, their variable morphology can occasionally create difficulty in diagnosis. Reporting pathologists should be aware that schwannomas can exhibit a broad spectrum of morphological patterns. Clinical and radiological examinations can show correlation and should be performed, in conjunction with ancillary tests, when appropriate. Furthermore, deferring a definitive diagnosis until excision may be necessary for small biopsy specimens and frozen sections. This report underscores these challenges through examination of two unique schwannoma cases, one predominantly cellular and the other myxoid, both of which posed significant challenges in histological interpretation.

[Plexiform fibrohistiocytic tumor]

Plexiform fibrohistiocytic tumors are rare, low-to-moderate malignant soft tissue tumors that occur primarily in children and adolescents and are located on the upper extremity. The diagnosis must be made histologically. We report on a young woman who presented a growing, painless lesion on the cubital fossa. Histopathology as well as the standard of treatment are discussed.

Superficial CD34-Positive Fibroblastic Tumor: Two Case Reports

Superficial CD34-positive fibroblastic tumor (SCPFT) is a recently described disease entity characterized by marked nuclear pleomorphism, low mitotic count, and diffuse CD34 positivity. It is a rare, distinctive, low-grade fibroblastic neoplasm. To date, only 44 cases have been reported in the English-language literature. Herein, we report two cases of SCPFT involving a 48-year-old male and a 22-year-old male with superficial tumors on the right and left thighs, respectively. Excision was performed in both cases. Histologically, both tumors showed spindle-to-epithelioid cells arranged in fascicular or sheet-like patterns. Most cells displayed granular or eosinophilic glassy cytoplasm, marked nuclear pleomorphism, and a low mitotic rate. On immunohistochemical staining, tumor cells were diffusely positive for CD34 and negative for S100 protein, smooth muscle actin, and desmin. After wide excision, neither patient experienced recurrence or metastasis after 16 months and 11 months of clinical follow-up, respectively. To the best of our knowledge, these are the first two cases of SCPFT reported in Korea. We believe these case reports would contribute to the clinicopathological understanding of SCPFT and assist clinicians in differentiating this tumor from other superficial soft tissue neoplasms.

The clinicopathological spectrum of sclerosing epithelioid fibrosarcoma: report of an additional series with review of the literature

We present a case series of sclerosing epithelioid fibrosarcoma (SEF) to further characterise its clinical and pathological features. Twenty-one patients with SEF were included in this study. There were 12 males and nine females (range 25-63 years; median 38 years). Tumours were located in the kidney (n=5), thigh (n=3), chest wall (n=3), head and neck (n=2), bone (n=2), abdominal wall (n=1), psoas major (n=1), retroperitoneum (n=1), omentum (n=1), popliteal space (n=1) and lung (n=1). Tumour sizes ranged from 2.5 to 16 cm (median 7 cm). Microscopically, epithelioid tumour cells were arranged in nests and cords and embedded in a dense sclerotic stroma. Some tumours showed myxoid areas, fibroma-like areas, acinar growth patterns and haemangiopericytoma-like appearance. A few tumour cells presented a rhabdomyoid shape. Calcification, ossification, cystic and necrosis were observed in some cases. The diagnosis was confirmed by immunoreactivity for MUC4, and by further fluorescence in situ hybridisation (FISH) or next generation sequencing (NGS) analysis. Clinical follow-up was available for 16 cases (median, 24 months; range 6-62 months). Seven patients developed metastases to lung (n=3), bone (n=3), brain (n=2) and back (n=1). Four patients developed a local recurrence. Three patients died of disease. Overall survival (OS) of SEF was related to patient age (p=0.001) and progression-free survival (PFS) was related to tumour size (p=0.046). In addition to soft tissue, SEF is more likely to involve the viscera and the abdominal cavity and has morphological variants. Familiarity with its distinctive clinical and pathological features helps avoid misdiagnosis.

Musculoskeletal oncology and thermal ablation: the current and emerging role of interventional radiology

The role of interventional radiology (IR) is expanding. With new techniques being developed and tested, this radiology subspecialty is taking a step forward in different clinical scenarios, especially in oncology. Musculoskeletal tumoral diseases would definitely benefit from a low-invasive approach that could reduce mortality and morbidity in particular. Thermal ablation through IR has already become important in the palliation and consolidation of bone metastases, oligometastatic disease, local recurrences, and treating specific benign tumors, with a more tailored approach, considering the characteristics of every patient. As image-guided ablation techniques lower their invasiveness and increase their efficacy while the collateral effects and complications decrease, they become more relevant and need to be considered in patient care pathways and clinical management, to improve outcomes. We present a literature review of the different percutaneous and non-invasive image-guided thermal ablation methods that are currently available and that could in the future become relevant to manage musculoskeletal oncologic diseases.

Haemorrhagic soft-tissue sarcoma: Oncological outcomes and prognostic factors for survival

INTRODUCTION

Haemorrhagic soft-tissue sarcomas (HSTS) are characterised by aggressive local growth and highly metastatic behaviour. We aimed to describe oncological outcomes and prognostic factors.

MATERIALS AND METHODS

Retrospective review including 64 patients treated with palliation (n = 7), with limb salvage surgery (LSS) (n = 9), with neoadjuvant radiotherapy (RT) + LSS (n = 12), with LSS + adjuvant RT (n = 30) or amputation (n = 6). Kaplan-Meier survival analysis estimated overall survival (OS), metastasis-free survival (MFS) and local recurrence-free survival (LRFS). After uni- and multivariate analysis, prognostic factors affecting OS, MFS and LRFS were identified.

RESULTS

Median age was 67 years (IQR 23 years) with median follow-up of 11 months (IQR 28 months). All cases were high grade. Eight (13%) had pulmonary metastases at presentation and another 40 (63%) developed metastases after median 9 months (IQR 19 months). Median OS was 12 months (IQR 38 months), and estimated OS after two-years was 15.9% and 52.9% for patients with and without metastatic disease at presentation, respectively. Improved OS was associated with negative resection margins (p = 0.031), RT (p = 0.045), neoadjuvant RT (versus adjuvant RT, p = 0.044) and amputation (versus LSS, p < 0.001). MFS was 35.1% after two-years. LR occurred in 18 of 51 (35.3%) patients with surgically treated localised disease. LRFS was 63.4% after two-years and significantly affected by a negative margin (p = 0.042) and RT (p = 0.001).

CONCLUSION

Haemorrhagic soft-tissue sarcomas should be excised, either with amputation or LSS with a clear resection margin. If LSS is attempted, neoadjuvant RT reduces the risk of tumour spillage and early LR, enhances the feasibility of achieving clear resection margins, and offers superior overall survival compared to adjuvant RT.

Schwannoma of Posterior Interosseous Nerve: A Case Report and Review of Literature

Schwannomas constitute only 5% of tumors of upper limb. Schwannoma of the posterior interosseous nerve is rare. A thorough search of literature revealed only three case reports of this entity. A 33-year old female presented with insidious onset swelling over extensor aspect of right forearm for one year and deficit of extension of fourth and fifth finger for a month. Magnetic Resonance Imaging and Fine Needle Aspiration Cytology were suggestive of low- grade nerve sheath tumor. The tumor was excised under tourniquet control and magnification, using microsurgical technique. Histopathology confirmed schwannoma. Result. Patient regained her full extension of fourth and fifth finger within 1.5 months. As schwannoma does not infiltrate the nerve fibers, so a complete surgical excision is the treatment of choice. We wrote this article to draw clinicians' attention to this unusual entity. Schwannoma of PIN is a relatively rare condition. Till date, there are only three cases reported in literature. Meticulous attention to detail is required while excising large schwannomas, as there is a risk of fascicular injury during dissection. Use of magnification and microsurgical technique prevents inadvertent nerve injury.

Primary uterine osteosarcoma arising in a leiomyoma with rapid local recurrence: A case report

Background

Extraskeletal osteosarcoma is an extremely rare malignant neoplasm. Literature regarding primary osteosarcoma of the uterus is confined to only a small number of case reports. Case: A 57-year-old female with a history of uterine fibroids presented to the emergency department with abdominal pain. Imaging was notable for an enlarged uterus with a 15 cm calcified fibroid extending along the posterior uterus. The patient underwent a laparotomy for total hysterectomy and bilateral salpingo-oophorectomy. Pathological evaluation of the specimen yielded mesenchymal proliferation with osteoid formation and tumor cells with densely eosinophilic cytoplasm resembling osteoblasts with a final diagnosis of primary uterine osteosarcoma. Multidisciplinary tumor board recommended against adjuvant treatment, given the lack of evidence for improved outcomes for early-stage uterine sarcomas. The patient was followed up with surveillance visits every-three months, entailing physical examination and computed tomography(CT) scans. Unfortunately, she had locoregional oligometastatic recurrence of her disease at 1-year follow up.

Conclusion

Primary uterine osteosarcoma is an extremely rare and aggressive neoplasm with limited understanding regarding optimal treatment options.

Prediction of lipomatous soft tissue malignancy on MRI: comparison between machine learning applied to radiomics and deep learning

Objectives

Malignancy of lipomatous soft-tissue tumours diagnosis is suspected on magnetic resonance imaging (MRI) and requires a biopsy. The aim of this study is to compare the performances of MRI radiomic machine learning (ML) analysis with deep learning (DL) to predict malignancy in patients with lipomas oratypical lipomatous tumours.

Methods

Cohort include 145 patients affected by lipomatous soft tissue tumours with histology and fat-suppressed gadolinium contrast-enhanced T1-weighted MRI pulse sequence. Images were collected between 2010 and 2019 over 78 centres with non-uniform protocols (three different magnetic field strengths (1.0, 1.5 and 3.0 T) on 16 MR systems commercialised by four vendors (General Electric, Siemens, Philips, Toshiba)).

Two approaches have been compared: (i) ML from radiomic features with and without batch correction; and (ii) DL from images. Performances were assessed using 10 cross-validation folds from a test set and next in external validation data.

Results

The best DL model was obtained using ResNet50 (resulting into an area under the curve (AUC) of 0.87 ± 0.11 (95% CI 0.65−1). For ML/radiomics, performances reached AUCs equal to 0.83 ± 0.12 (95% CI 0.59−1) and 0.99 ± 0.02 (95% CI 0.95−1) on test cohort using gradient boosting without and with batch effect correction, respectively. On the external cohort, the AUC of the gradient boosting model was equal to 0.80 and for an optimised decision threshold sensitivity and specificity were equal to 100% and 32% respectively.

Conclusions

In this context of limited observations, batch-effect corrected ML/radiomics approaches outperformed DL-based models.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41747-022-00295-9.

Aggressive Intra-Abdominal Fibromatosis in an Adolescent Girl - An Unusual Sequelae to Ovarian Germ Cell Tumor

BACKGROUND

Abdominal fibromatosis presenting as an abdominal mass is a rare occurrence in a gynecological setting. The diagnosis might not be suspected preoperatively, and management could be challenging.

CASE

An 18-year-old girl with ovarian germ cell malignancy was managed with staging laparotomy and chemotherapy. She developed a large abdominal mass 10 months later. An abdominopelvic mass (40 × 20 cm) was removed at laparotomy. The histopathological diagnosis was intra-abdominal fibromatosis. A rapidly growing abdominal mass recurred postoperatively. After discussion with the tumor board, chemotherapy with methotrexate and vinblastine was started. The tumor was not responsive, and the patient succumbed after the second cycle of chemotherapy.

SUMMARY AND CONCLUSION

Abdominal fibromatosis should be considered among the differential diagnoses of a rapidly growing abdominal mass after resection of an ovarian germ cell tumor.

[Giant cell-containing tumors of bone and differential diagnoses]

Osteoclastic giant cells represent a common cellular component of lesions arising in bone. Highlighting this morphological finding, the current WHO classification of bone tumors defines a diagnostic group comprising aneurysmal bone cyst, giant cell tumor of bone and non-ossifying fibroma, which may display morphologic similarities while being distinct with regard to molecular and biological features. Starting with these tumors - putting a focus on lesions arising in bone - this article gives a survey of other (chondrogenic and osteogenic) tumors that frequently contain osteoclastic giant cells, which may, particularly in small biopsies, enter differential diagnosis. Overlapping features with selected giant cell-containing soft tissue tumors, which may be of differential diagnostic relevance in daily routine, are discussed.

Fibro-osseous pseudotumor of the digit: a case report

Fibro-osseous pseudotumor is a poorly reported benign ossifying tumor. Due to its aggressiveness and lack of specificity, the lesion has previously been mistaken for a malignant lesion, leading to unnecessary radical treatment. Our case warns our readers of the aggressiveness of the tumor and rational surgical planning. In our case, a 25-year-old male patient presented with a painless, enlarging mass in the left index finger that had developed over the course of 5 months. The lesion was first partially surgically removed for biopsy, which confirmed the lesion to be fibro-osseous pseudotumor. Considering the possibility of skin necrosis from complete excision, complete removal was postponed until the second surgery. However, the residual lesion rapidly progressed, reaching its original size within 4 months. Another lesionectomy was performed to thoroughly remove the recurrent lesion surrounding the joint capsules. The intraoperative frozen section again supported the initial diagnosis and recurrence. During the 2-year follow-up, there were no signs of recurrence, and the function of the finger was fully recovered. Fibro-osseous pseudotumor should be considered in the differential diagnosis of rapidly progressive lesions affecting the digits. Complete surgical excision is the treatment of choice. However, the surgical strategy should be cautiously planned because of the aggressiveness of fibro-osseous pseudotumor and the possibility of saving the involved digit.

Primary cutaneous Leiomyosarcoma on the left iliac region: A rare case report from Syria

Introduction

and importance: Leiomyosarcoma is a rare aggressive soft-tissue malignancy typically originating from embryonic mesoderm or mesenchymal cell lines in smooth muscles.

Leiomyosarcoma of the skin is termed as “Dermal Leiomyosarcoma”, and is categorized into two subdivisions; superficial cutaneous and deep subcutaneous.

Both types begin either as primary lesions or metastatic lesions from distant sites.

Case presentation

We report the case of a 60-year-old male patient with Primary Cutaneous Leiomyosarcoma (PCL) located in the left iliac region.

His history is insignificant and he has no family or genetic history of leiomyosarcoma. The lesion was itchy without any other symptoms and existed 20 years before our evaluation.

A biopsy from the nodule was performed and sent to the pathology department, where the section was stained with smooth muscle actin stain (SMA) and the result was positive.

We referred the patient to a surgeon to excise the nodule. The lesion was excised with a 3cm safety margin, the eradication includes also the of the major iliac muscle.

After one year of follow-up there was no metastasis nor recurrence.

Conclusion

Primary Cutaneous Leiomyosarcoma is a very rare malignancy and it is hard to diagnose without biopsy and pathological examination.

•

Primary cutaneous Leiomyosarcoma is a very rare tumor.

•

Accurate diagnosis cannot be made without histological and immunohistochemical examination.

•

Surgery is the only guaranteed treatment and other methods are still controversial.

[Preoperative versus postoperative radiotherapy in soft tissue sarcomas: State of the art and perspectives]

Radiation therapy is a standard treatment for limbs soft tissue sarcomas. Preoperative versus postoperative radiotherapy has been a controversial topic for years. With preoperative irradiation, the treatment volume is more limited, the delivered dose possibly lower and the tumor volume easier to delimit. Only one randomized trial compared these two irradiation sequences. The results in terms of local control and survival were equivalent but the risk of acute postoperative complications was higher if irradiation was administered before surgery. However, in the latest update of this trial, patients who received adjuvant irradiation exhibited more severe late toxicity than those treated preoperatively. In addition, with modern irradiation techniques such as conformal with image-guided intensity modulated radiotherapy and flap coverage techniques, the incidence of complications after preoperative irradiation were lower than historically published rates. Locally advanced proximal sarcomas and the failure of other neoadjuvant treatments are nowadays classical indications for preoperative irradiation. As with other neoadjuvant treatments, induction radiotherapy must be personalized according to the histological subtype, the tumor site and the benefit/risk ratio, which is best appreciated by a multidisciplinary surgical and oncological team in a specialized center in the management of soft-tissue sarcomas.

Soft Tissue Perivascular Epithelioid Cell Tumour: An Unusual Finding

Perivascular epithelioid cell tumour (PEComa) is a rare mesenchymal tumour made up of clear perivascular cells with epithelioid characteristics, which co-expresses muscle and melanocytic markers with a component of spindle cells, like sarcoma and variety of other tissues. This time, we present the case of a young patient with a tumour in the dorsal region of progressive growth, compatible with PEComa of soft tissue after histopathological and immunohistochemical analysis.

A Plum On Thumb: A Rare Presentation Of Synovial Sarcoma

Synovial sarcoma (SS) is a rare and aggressive mesenchymal tumour accounting for around 5-10% soft tissue neoplasms usually found in joints of upper and lower extremities. A 35years old healthy looking male patient from Afghanistan presented with swelling on palmar side of base of thumb from last one year. Seven months back excisional biopsy was taken report of which showed neurofibroma/dermatofibroma with. No evidence of malignancy seen. From last 5months mass reappeared and gradually increased in size with itching sensation and mild pain. On local examination there was 5×4×5 cm reddish mass on palmar surface of base of thumb with extension into mid thenar eminence with diffuse margins. X-ray showed soft tissue density mass with spikes of calcification. Ultrasound showed 4.2×4×4.5 cm heterogeneous solid lesion on anteromedial surface of root of right thumb without any remarkable intralesional calcification and remarkable intralesional vasculature. MRI reported lobulated well defined soft tissue mass eliciting low to intermediate signal on T1 and WIs and bright signal on T2and STIR Vividly enhancing mass. Case was operated mass was excised and biopsy sent. Post op status was unremarkable. Biopsy reported poorly differentiated biphasic synovial sarcoma. No recurrence seen till 3months.

[Solitary locoregional metastasis of an undifferentiated pleomorphic sarcoma in the M. quadratus femoris]

Das undifferenzierte pleomorphe Sarkom („undifferentiated pleomorphic sarcoma“ [UPS]) gehört zur Gruppe der Weichteilsarkome und macht fast 10 % aller Weichteilsarkome aus. Der Fall eines 49-jährigen Patienten wird vorgestellt, bei dem die kompartmentorientierte Resektion eines primären UPS im linken Musculus gluteus maximus mit adjuvanter Radiotherapie (60 Gy) durchgeführt wurde. Im Rahmen der Tumornachsorge (3 Jahre später) wurde eine lokoregionäre Metastase an einer ungewöhnlichen Lokalisation im M. quadratus femoris festgestellt, welche mittels einer In-toto-Resektion mit intraoperativer Radiotherapie (10 Gy) behandelt wurde. Der intra- und postoperative Verlauf gestalten sich komplikationslos ohne neurologische Defizite. Im Rahmen der Nachtuntersuchung 6 Monate postoperativ war der Patient tumor- und beschwerdefrei.

Angioleiomyoma masquerading as shoulder pain

Angioleiomyoma is a benign soft tissue tumor originating from vascular smooth muscle. We report a case of a 20-year-old student who presented with pain in the right shoulder of 4 years duration. Shoulder movements were pain-free throughout the range of motion except resisted external rotation. Magnetic resonance imaging visualized a well-circumscribed lesion over the infraspinatus tendon. The lesion was surgically removed and sent for histopathological analysis. Morphology and immunohistochemistry results were suggestive of angioleiomyoma. The most common location for such a lesion is the lower limb, with less than 1% being reported in the upper arm, of which an angioleiomyoma of the shoulder is extremely rare.

Maxillary Sinus Myxofibrosarcoma Mimicking Nodular Fasciitis: A Rare Case Report

Myxofibrosarcoma (MFS) is a fibroblastic soft tissue sarcoma that is extremely rare in the maxillofacial region. Due to its non-specific clinicoradiographic findings and challenging histopathological features, the diagnosis is difficult. Here, we present a case of MFS which was first diagnosed as nodular fasciitis. The initial examination of the incisional biopsy showed a benign-appearing proliferation of fibroblasts without features of malignancy. The patient returned with recurrence four months after surgical excision of the primary lesion. The second histologic study revealed a high-grade spindle cell sarcoma with myxoid features most compatible with MFS. Definitive diagnosis of MFS was confirmed by these histopathologic features and supportive immunohistochemical stains. Unfortunately, the patient died of disease 3 months later.

Soft tissue pathology for the radiologist: a tumor board primer with 2020 WHO classification update

Radiologists serve an important role in the diagnosis and staging of soft tissue tumors, often through participation in multidisciplinary tumor board teams. While an important function of the radiologist is to review pertinent imaging and assist in the differential diagnosis, a critical role is to ensure that there is concordance between the imaging and the pathologic diagnosis. This requires a basic understanding of the pathology of soft tissue tumors, particularly in the case of diagnostic dilemmas or incongruent imaging and histologic features. This work is intended to provide an overview of soft tissue pathology for the radiologist to optimize participation in multidisciplinary orthopedic oncology tumor boards, allowing for contribution to management decisions with expertise beyond image interpretation.

[Clinicopathological and molecular genetic features of lipofibromatosis-like neural tumor]

Objective: To investigate the clinicopathological and molecular genetic features of lipofibromatosis-like neural tumor(LPF-NT). Methods: Three cases of LPF-NT in Children's Hospital of Fudan University from December 2018 to December 2019 were analyzed for their diagnosis and differential diagnosis. Results: One case was male and two cases were females, all of them aged under 1 years old. The clinical manifestation of LPF-NT was a local infiltrative growth mass in subcutaneous tissue. There were no specific radiologic features. Histologically, dense fascicles or compact sheets of spindle cells showed infiltration into subcutaneous adipose tissue. Spindle cells displayed a moderate degree of nuclear atypia with mitotic activity cells.Immunohistochemical study showed the tumor cells diffusely expressed S-100 protein, CD34, NTRKI, and pan-TRK. Fluorescence in situ hybridization detected rearrangement of NTRK1 gene in all 3 cases tested. Conclusions: LPF-NT is a newly named soft tissue tumor. Histological morphology, immunohistochemistry and molecular detection are helpful for the diagnosis and differential diagnosis of the disease.

The diagnostic value of ultrasound and shear wave elastography in the differentiation of benign and malignant soft tissue tumors

AIM

To evaluate the diagnostic value of ultrasound (US) and shear wave elastography (SWE) in the differentiation of benign and malignant soft tissue tumors.

MATERIALS AND METHODS

A hundred and nine patients (mean age 43.3 ± 20.5, range 0-85; 64 men and 45 women) diagnosed with soft tissue tumors between August 2016 and January 2020 were evaluated with US and SWE. The stiffness of the lesions was measured as mean and maximum shear wave velocity (SWV_mean and SWV_max) in meters/second (m/s). Two radiologists evaluated the US images independently and then reached a final consensus. Final diagnosis was obtained either by histopathological examination (core needle biopsy or surgery) or by follow-up. The diagnostic value of US and SWE in the differentiation of malignant and benign lesions was assessed.

RESULTS

Pathology results revealed 37 malignant and 43 benign lesions. Twenty-nine lesions were benign based on follow-up criteria. Consensus US reading revealed 91.9% sensitivity and 72.2% specificity with almost perfect inter-observer agreement (κ = 0.802). Larger lesion size, male gender, advanced patient age, deep location, hypoechoic and hypervascular appearance, ill-defined margins, and presence of cystic area were associated with malignant diagnosis (p < 0.001, p = 0.010, p = 0.001, p = 0.001, p = 0.003, p < 0.001, p = 0.001, and p = 0.011, respectively). Median SWV_mean and median SWV_max of malignant lesions (2.87 and 2.68) were not significantly different than those of the benign lesions (3.30 and 3.05; p = 0.271 and p = 0.402, respectively).

CONCLUSION

US features can differentiate malignant and benign soft tissue tumors, whereas SWE did not contribute to the differentiation of soft tissue tumors.

A Case of Pseudomyogenic Hemangioendothelioma of the Lower Extremity

Pseudomyogenic hemangioendothelioma (PMH) is a rare vascular tumor and was recently recognized as a distinct entity. It has a predilection for young male adults and it frequently occurs in distal extremities. Although it is known to follow an indolent course, multi-focal presentation and local recurrence are common. PMH should be differentiated from epithelioid sarcoma, epithelioid hemangioendothelioma, dermatofibrosarcoma protuberans, and rhabdomyosarcoma. Its characteristic immunohistochemical staining pattern and recurrent translocation t(7:19)(q22:q13) are the basis for its diagnosis. Surgical excision is the mainstay treatment, although chemotherapy can be considered in non-operable patients. We present a rare case of a 40-year-old Korean male patient diagnosed with PMH through an excisional biopsy to facilitate the recognition PMH in the clinical practice.

[Clinicopathological characteristics of indeterminate dendritic cell tumor of four cases]

Objective: To investigate the clinicopathologic features, diagnosis, differential diagnosis and molecular pathological characteristics of indeterminate dendritic cell tumor (IDCT). Methods: Four cases of IDCT were collected at Peking Union Medical College Hospital (3 cases) and Fujian Provincial Hospital (1 case). The 4 cases were analyzed, with focus on morphology, immunohistochemistry and BRAF V600E detection. Related literature was reviewed to reveal the characteristics of this tumor. Results: There were 2 males and 2 females aged 30-52 years (mean=40 years). Histopathological characteristics of the tumor cells were round, polygonal. The nuclei were round, with rich eosinophils cytoplasm. The tumor cells arranged in diffuse, sheet, whorl, and fascicle patterns. Mitosis was variable [generally(1-3)/10 HPF] and nucleoli were obvious. Lymphocytes, plasma cells and other infiltrates could be seen in the stroma. Immunohistochemically, tumor cells were positive for S-100 (4/4), CD1a (4/4), CD68 (4/4) and cyclin D1 (3/3), while CD207/Langerin, CKpan, CD21, HMB45, ALK and actin were negative. Ki-67 index was 5%-30%. Gene detection showed BRAF V600E mutations were not present in any of the four cases. Conclusions: IDCT is a rare type of dendritic cell tumor. There are no specific morphology characteristics. The diagnosis depends on clinical, histopathological and immunophenotype. Thus, electron microscopy and molecular testing are helpful if necessary.

[Clinicopathological characteristics of myxoid solitary fibrous tumor: analysis of seven cases]

Objective: To investigate the clinicopathological characteristics, immunophenotypes, and diagnostic and differential diagnostic features of myxoid solitary fibrous tumor (SFT). Methods: Seven cases of myxoid SFT were collected from the archives of Zhejiang Provincial People's Hospital from January 2014 to December 2019. The clinical features, histomorphology, immunohistochemistry, molecular genetics and prognosis were analyzed and the relevant literature was reviewed. Results: There were three male and four female patients ranging from 32 to 67 years. Locations included the pleura (three cases), pelvic cavity, vagina, parotid gland, and nasal cavity(one each). Tumor size ranged from 2.7 to 13.5 cm. Histologically, all cases were characterized predominantly by the presence of myxoid stroma comprising 55% to 90% of the tumor (mean 72%). The tumors were composed of predominantly stellated, spindled or ovoid cells disposed haphazardly, in loose fascicles, or in anastomosing strands imparting a microcystic/reticular appearance in a extensively myxoid, richly vascularized stroma. Staghorn-shaped branching vessels and thin strands of collagen were commonly seen between tumors cells amidst the myxoid background. These myxoid areas were punctuated by small cellular areas showing diagnostic features of classical SFT, which were present in all seven cases. Areas showing giant cell angifibroma-like change were noted in 2 cases and focal lipomatous metaplasia was identified in 1 case. Atypical features suggestive of aggressive behavior were present in 2 cases and in one of the cases myxoid SFT with high-grade sarcomatous overgrowth was noted. Immunohistochemically, tumor cells in all cases stained positively for STAT6 and CD34. Polymerase chain reaction technique showed in both the examined cases the characteristic NAB2ex4-STAT6ex2 fusion gene. According to the Demicco's risk assessment model, four cases were classfied as low, one was classified as moderate and 2 was classified as high. Follow-up information was obtained in 4 cases. One tumor recurred 3 times within 48 months after operation, and the other 3 cases had no tumor recurrence and metastasis. Conclusions: Myxoid SFT represents a rare morphologic variant of SFT with biological behaviors ranging from indolent to aggressive. Myxoid SFT should be included in the differential diagnostic spectrums of soft tissue tumors with significantly myxoid change. Carefully searching for the typical SFT histomorphology with the use of immunohistochemistry and if necessary, molecularly testing for NAB2-STAT6 fusion can help to distinguish myxoid SFT from its many mimickers.

Accuracy of ultrasound in the characterisation of deep soft tissue masses: a prospective study

PURPOSE

To investigate the accuracy of ultrasound in characterising the type of mass and likelihood of malignancy in deep soft tissue masses.

METHODS

Five hundred seventy-nine deep soft tissue masses were prospectively studied by ultrasound. Masses (n = 137) with prior MRI or CT were not included. Following ultrasound examination, the likely nature of the mass as well as the confidence of the reporting radiologist ('fully confident' versus 'not fully confident') about the ultrasound diagnosis was recorded. Clinical and ultrasound diagnoses were compared with the histological diagnosis which was available in 134 (23%) of the 579 masses.

RESULTS

Compared with histology, clinical and ultrasound accuracy for characterising the type of mass were 47% and 88% respectively when all differential diagnoses were considered. The radiologist was fully confident regarding the type of 436 (75%) of 579 masses and, in this setting, for those cases that could be compared with histology, diagnostic accuracy was 96%. For the remaining masses, where the radiologist was not fully confident, accuracy compared with histology was 58% for the first differential diagnosis and 80% for all differential diagnoses. For identifying malignancy, sensitivity, specificity, and positive and negative predictive value of ultrasound were 97%, 58%, 67%, and 99% respectively. Ultrasound alone was considered sufficient for diagnostic workup in over half of all deep soft tissue masses.

CONCLUSION

Ultrasound is useful at characterising and recognising malignancy in deep soft tissue masses. Provided local practice patterns are favourable, ultrasound may be considered a first-line investigation in the diagnostic workup of deep soft tissue masses.

KEY POINTS

• In three-quarters of cases, one can be fully confident about characterising the nature of deep soft tissue masses on ultrasound and, for those fully confident cases that could be compared with histology, the diagnostic accuracy of ultrasound was 96%. • Ultrasound can correctly recognise nearly all malignant deep soft tissue masses but some benign masses will also be considered possibly malignant. • Ultrasound alone was considered sufficient for imaging workup in over half of deep soft tissue masses.

Diagnostic utility of perilesional muscle edema in myositis ossificans

OBJECTIVES

To investigate the value of extensive perilesional muscle edema for the differentiation between myositis ossificans (MO) and malignant intramuscular soft tissue tumors on MRI.

MATERIALS AND METHODS

Two blinded readers analyzed MR examinations of 90 consecutive patients with intramuscular soft tissue masses (group 1: MO, n = 20; group 2: malignant tumors, n = 70). Extent of edema around lesions was graded (0, none; 1, minimal edema; 2, moderate edema; 3, extensive edema). Edema-lesion ratio (ELR = ratio of the maximal diameter of the edema and the maximal diameter of the central lesion) was calculated. ROC analysis, Mann-Whitney U test, and Kappa test were used.

RESULTS

A total of 70% and 60% of patients with MO had edema grade 3 (reader 1/reader 2), 30%/40% edema grade 2. For the patients with malignant tumors, it was 2.9%/1.4% (edema grade 3) and 16%/23% (edema grade 2). Interrater reliability was substantial (kappa = 0.66). Extent of edema was significantly higher for patients of group 1 (p < 0.0001, both readers). Mean ELR was 3.60 (group 1) and 1.35 (group 2), with statistically significant differences (p < 0.0001). Grade 3 edema showed a sensitivity/specificity of 70%/97.1% (reader 1) and 60%/99% (reader 2) for diagnosing MO. For ELR > 2.0, sensitivity was 90% and specificity 91% for diagnosing MO.

CONCLUSIONS

Extensive perilesional muscle edema on MRI of more than double the size of the central lesion is highly specific, but not pathognomonic for myositis ossificans in the early/intermediate stage in the differentiation to malignant intramuscular soft tissue lesions.

Stumbling upon the unexpected: A unique presentation of phosphaturic mesenchymal tumor in the hindfoot

We describe an unexpected and unique case of phosphaturic mesenchymal tumor in a 38-year-old female presenting with a painful lump in the plantar hindfoot. Phosphaturic mesenchymal tumors are extremely rare, generally benign soft tissue or osseous tumors, which are associated with overexpression of fibroblast growth factor-23 and tumor-associated osteomalacia. Patients often present with progressive signs and symptoms including systemic bone pain, muscle weakness, and insufficiency fractures, and timely diagnosis is paramount to appropriate therapy. Tumor resection is almost always curative with normalization of laboratory markers and resolution of symptomatology.

[Late complications following neo-/adjuvant radiotherapy and surgery for sarcomas of the extremities or pelvis/retroperitoneum : Preventative measures]

Radiotherapy is one of the pillars in the multimodal therapy of sarcomas of the extremities or pelvis/retroperitoneum. It can be delivered prior to or following surgery. Novel radiation techniques, such as intensity-modulated radiotherapy using high-energy photons or protons, contribute to the reduction of acute and late toxicities. This review article summarizes these concepts.

Papillary intralymphatic angioendothelioma: Dabska tumor

Papillary intralymphatic angioendothelioma (Dabska tumor) is a rarely metastasizing lymphatic vascular neoplasm that usually affects children and young adults. The majority of these cases occur in soft tissues of extremities, and to date less than 40 cases have been described. Despite the generally indolent evolution, can be locally invasive with the potential to metastasize. We describe a case of a young woman presenting with a plantar lesion, for 9 months and histological diagnosis of Dabska tumor. This neoplasm should be considered in the differential diagnosis of vascular dermatoses, allowing early diagnosis and treatment. Long-term follow-up should be performed.

Cervical Myxoid Solitary Fibrous Tumor: Report of an Unusual Variant and a Brief Overview of the Literature

We present a 49 year old female with a diagnostically challenging myxoid solitary fibrous tumor arising in the soft tissue of the neck. The tumor was diffusely positive for CD34 and STAT6 on immunohistochemistry.

Soft tissue sarcoma: DWI and DCE-MRI parameters correlate with Ki-67 labeling index

OBJECTIVES

To examine the correlation of diffusion-weighted and dynamic contrast-enhanced magnetic resonance imaging (MRI) parameters with Ki-67 labeling index (LI) in soft tissue sarcoma (STS).

METHODS

The institutional review board approved this retrospective study, and the requirement for informed consent was waived. Thirty-six patients with STS who underwent 3.0-T MRI, including diffusion-weighted and dynamic contrast-enhanced MRI, between July 2011 and February 2018, were included in this study. The mean and minimum apparent diffusion coefficients (ADCs) (ADC_mean and ADC_min, respectively), volume transfer constant, reflux rate, and volume fraction of the extravascular extracellular matrix of each lesion were independently analyzed by two readers. Their relationship with the Ki-67 LI was examined using Spearman's correlation analyses. Differences between low- and high-proliferation groups based on Ki-67 LI were evaluated statistically. Optimal cut-off points were determined using the area under the curve analysis for significant parameters. Interobserver agreement was assessed with the intraclass correlation coefficient.

RESULTS

ADC_mean (ρ = - 0.333, p = 0.047) was significantly and inversely correlated with Ki-67 LI. The high-proliferation group showed a significantly lower ADC_mean than did the low-proliferation group (median, 1.08 vs. 1.20; p = 0.048). When a cut-off ADC_mean value of 1.16 × 10^-3 mm²/s was used, the sensitivity, specificity, and area under the curve for differentiating low- and high-proliferation groups were 75.0%, 60.0%, and 0.712, respectively. Interobserver agreements between the two readers were almost perfect for all parameters.

CONCLUSIONS

ADC_mean was correlated with Ki-67 LI and could help differentiate between STS with low and high proliferation potential.

KEY POINTS

• ADC _meanwas significantly and inversely correlated with Ki-67 labeling index in soft tissue sarcoma. • In the high-proliferation group, ADC _meanvalues were significantly lower than those of the low-proliferation group.

[Ultrasound and MRI features of malignant fibrous histiocytoma of soft tissue]

OBJECTIVE

To investigate ultrasound and MRI features of malignant fibrous histiocytoma (MFH) of soft tissue.

METHODS

Ultrasound, MRI images and pathological data of 12 patients with malignant fibrous histiocytoma in soft tissue confirmed by operation and pathology were analyzed from January 2012 to August 2018, inlcuding 7 males and 5 females, aged from 36 to 69 years old with an average age of 53 years old; the courses of disease ranged from 4 to 49 months with an average of 28 months. Clinical manifestations were soft tissue masses and pain in the affected limbs. Ultrasound, MRI and contrast-enhanced examination were performed before operation. The lesions, morphology, echo/signal characteristics, color flow signals and enhancement features were observed and compared with pathology.

RESULTS

In 12 patients with MFH, 9 patients were primary lesions and 3 patients were recurrent lesions after operation. There were 7 cases of bilateral thighs, 2 cases of calves, 1 case of upper arm, 1 case of buttocks and 1 case of posterior peritoneum. The size ranged from 5.1 to 17.1 cm with an average of 8.7 cm. Ultrasound feature showed lobulated or agglomerate, and focused on low echo; 5 cases had capsule and with clear border; 7 cases were unclear boundary with surrounding tissues; and 6 cases with irregular echo-free. The blood flow signals were around the CDFI, and the internal blood flow signals were different. MRI feature showed lobulated, agglomerate or irregular shape, T1WI showed slightly lower signal or equal signal, T2WI showed high signal and DWI signal increased. Six patients manifested mixed signal inside, 7 patients manifested low signal separation inside, 5 patients with false envelope, and 9 patients manifested infiltration and growth with peripheral edema. T1WI showed uneven strengthening after enhancement. Immunohistochemical expression of Vim, CD68 were positive.

CONCLUSIONS

The age, location and imaging features of soft tissue MFH are characteristic. The diagnosis of MFH should be considered when irregular mass occurred in soft tissues of limbs at middle-aged and old people. Echo and signal are homogeneous or mixed. Separation, necrosis and cystic degeneration could be seen in the mass. When the blood flow signals are abundant and solid components are obviously enhanced, the diagnosis of MFH should be considered.

Factors Associated with Requesting Magnetic Resonance Imaging during the Management of Glomus Tumors

BACKGROUND

The characteristic clinical presentation of glomus tumors and the low negative predictive value of the magnetic resonance imaging (MRI) raise the question whether MRI improves their management. Therefore, this study aimed to investigate whether MRI improved the management of glomus tumors.

METHODS

In total, 87 patients with a histologically confirmed glomus tumor were treated over a 25-year period and analyzed retrospectively. Multivariable logistic regression analysis was used to evaluate the independent predictors of an MRI request during the management of glomus tumors.

RESULTS

ccording to the results, the patients who were treated by orthopaedic surgeons were more likely to have an MRI during the management of a glomus tumor.

CONCLUSION

The role of an MRI during the management of a glomus tumor is unclear. Orthopaedic surgeons are more likely to request an MRI. Furthermore, visible lesions with characteristic symptoms probably do not benefit from MRI. However, it may help to be sure that the highest-quality MRI is used with the best possible coil for the finger.

[Myxoid soft tissue tumours : An algorithm for differential diagnosis]

Soft tissue neoplasms with myxoid features are collectively not uncommon. Their often complex differential diagnosis makes them significantly over-represented among consultation cases. This applies not only to sarcomas but in particular to benign lesions as well. Generally, myxoid soft tissue lesions are divided into two major groups: (1) myxoid lesions by definition (which can however rarely be non-myxoid) and (2) rare myxoid variants of otherwise non-myxoid entities.Four major diagnostic challenges are responsible for the complexity of myxoid soft tissue neoplasms: (1) Diagnosis of malignancy in many cases is not based on conventional malignancy criteria but is defined by the entity itself, making under-diagnosis of malignancy likely in entities such as low-grade fibromyxoid sarcoma. (2) On the other hand, harmless myxoid lesions with features of high proliferation, e.g. nodular and proliferative fasciitis, tend to be over-diagnosed as malignant by the unworried. (3) The necessity to assess not only cellular morphology/differentiation, but also the stromal, vascular and architectural characteristics adds to the complexity of the differential diagnostic algorithm. (4) Last but not least, recognition of unexpected myxoid variants of non-myxoid entities is basically impossible if focal conventional areas are absent, underlining the need for high suspicion index and sufficient sampling.This review illuminates the various aspects related to the differential diagnostic workup of these challenging entities.

Systematic review of anorectal leiomyosarcoma: Current challenges and recent advances

BACKGROUND

The anorectal leiomyosarcoma (LMS) is an aggressive malignant neoplasm. Owing to the rarity of LMSs, an optimal treatment modality has yet to be determined.

AIM

To collect all published data on anorectal LMS characteristics, explore current treatment options, and review recent cases of postradiation LMS.

METHODS

A literature search of the PubMed electronic database was conducted using the MeSH terms “rectal neoplasms”, “anus neoplasms” and “gastrointestinal neoplasms” combined with “leiomyosarcoma”. The search was limited to English language and human studies. All available case reports and case series of anal or rectal LMSs that were published from the beginning of January 1996 to May 2017 were included if the diagnosis of LMS had been confirmed by histopathologic examination. Data were analyzed using simple statistics (mean, median, and standard deviation). Independent sample t-test was used to compare means for continuous variables.

RESULTS

A total of 27 articles reporting on 51 cases of anorectal LMS were identified. Among these cases, 11.7% had undergone previous pelvic radiotherapy (developing LMS at 13-35 years afterwards). Anorectal LMS affected the rectum in 92.2% of the cases, and no sex-based predominance was observed. Surgical resection with negative margins remains the mainstay of treatment, which can be accomplished with wide local excision or radical resection. The local recurrence rate was higher among cases who received wide local excision (30%), as compared to radical resection (20%); however, the overall rate of metastasis was 51.61% regardless of the treatment approach. The use of neoadjuvant radiation lowers the risk of local recurrence compared to adjuvant radiotherapy, and facilitates R0 resection of the tumor. Cases treated with adjuvant chemotherapy showed better rates of distant recurrence and overall survival. Nonetheless, multidisciplinary team discussion is necessary to determine the optimal management plan whilst considering patient- and disease-related factors.

CONCLUSION

A multidisciplinary team approach, considering the underlying patient- and disease- related factors, is necessary for optimal management of these complex tumors.

[Foot and ankle tumours : Part I: overview of incidence, diagnosis and staging of pedal tumours]

CLINICAL ISSUE

Foot and ankle tumours are rare. Part I of this paper provides a survey about tumour distribution regarding age and location of benign and malignant bone and soft tissue tumours.

STANDARD RADIOLOGICAL METHODS

All diagnostic radiological procedures are used for the diagnostic work-up of pedal tumours, in particular plain radiography, MRI, and ultrasonography.

METHODICAL INNOVATIONS

Dual-energy CT proves to be a valuable (differential) diagnostic tool in identifying urate dihydrate crystals.

PERFORMANCE

There are no reliable numbers available on accuracy of the aforementioned diagnostic procedures regarding tumour detection and identification. This is particularly true for soft tissue tumours which are small and well-defined, thus requiring histological clarification.

ACHIEVEMENTS

To evaluate pedal tumours correctly and reasonably, a full range of radiological diagnostics should be employed. Neither plain radiography alone nor a stand-alone MRI examination-depending on the tumour site-are sufficient to characterize such tumours including staging.

PRACTICAL RECOMMENDATIONS

Plain radiography remains the first-choice imaging modality. Ultrasonography is superior to reliably detect and identify ganglion cysts. MRI, however, continues to remain the upmost diagnostic modality of choice for evaluating foot and ankle tumours. CT possesses unchallanged diagnostic power to assess osseous changes. Bone scintigraphy (including SPECT-CT) and FDG-PET imaging are used when multifocal distribution or metastatic disease are suspected or to detect avidity of the pedal lesions, respectively.

[Foot and ankle tumours : Part II: Malignant bone tumours and soft tissue tumours of the foot with differential diagnostic hints]

CLINICAL ISSUE

Both benign and malignant tumours are encountered in the foot and ankle. Due to their rarity, however, diagnosis is often uncertain. Usual criteria such as tumour size, invasiveness or pain fail to differentiate benign from malignant neoplasias.

STANDARD RADIOLOGICAL METHODS

Plain radiography and-due to the complex foot anatomy-CT are important in the diagnostic evaluation of primary bone tumours. In the case of soft tissue tumours, ultrasonography is used to identify ganglion cysts. Tumour evaluation and staging are then performed using MRI. Nuclear imaging comes into play when multifocal, metastatic or systemic spread of the disease is suspected or if a biopsy procedure is planned.

METHODICAL INNOVATIONS

For the role of dual-energy CT, please refer to part I. Whether dual-energy CT is suitable to assess bone marrow oedema patterns is still debated.

SPECIAL FEATURES OF FOOT AND ANKLE TUMOURS

Primary bone tumours generally present in the ankle or the hindfoot. Malignant bone tumours, e. g. chondrosarcoma, are primarily found in the latter. On the other hand, soft tissue tumours generally present in the mid- and forefoot regions.

ACHIEVEMENTS

While the radiologic diagnostic evaluation of pedal bone tumours is quite reliable, caution is urgently needed in the case of soft tissue tumours because there are many confusing differential diagnoses.

PRACTICAL RECOMMENDATIONS

Proper X‑ray examination of the foot (at least in two plains) or with special views according to bony pathology is needed. All soft tissue masses that are not cysts should be evaluated further. MRI remains the diagnostic modality of choice but never stands alone! Caution: Size and well-defined margins of pedal soft tissue tumours are not considered criteria regarding whether a tumour is malignant or not.

[Epithelioid, biphasic and mixed tumors of soft tissue]

Epithelioid soft tissue tumors consist exclusively of epithelioid tumor cells. Biphasic tumors are composed of both a spindle-cell and an epithelioid component. The rare mixed tumors of soft tissue show a broader variety of cellular and stromal differentiation but also include at least one, possibly several, epithelioid portions.The close morphological similarity of some of these entities with each other, as well as with the more frequent soft tissue metastases of carcinomas, carcinosarcomas, and melanomas, to malignant mesothelioma and certain lymphomas, can often make the correct diagnosis extremely difficult. Recent advances in the detection of certain molecular alterations (mostly chromosomal translocations) have contributed to changes in tumor classification but also to improved pathological diagnostics (e.g. through the development of potent diagnostic antibodies) and biological understanding.The present overview should help the pathologist in the diagnosis of these rare tumors through the classical approach of morphological pattern recognition. The most important entities are discussed and illustrated in more detail, with the incorporation of the latest immunohistochemical and molecular aspects and the differential diagnosis of similar tumors.

Postoperative radiotherapy in primary resectable desmoid tumors of the neck: a case-control study

PURPOSE

Desmoid tumors (DTs) are rare soft tissue tumors, which frequently recur after surgery. The optimal treatment approach is still controversial due to lack of randomized data. The purpose of the study was to review a relative large series of DTs of the neck with emphasis on the value of postoperative radiotherapy (RT).

METHODS

A total of 68 patients with DTs of the neck region with or without postoperative RT between 1/2008 and 12/2017 were included. They were individually matched for factors including age, gender, tumor size and margin status with a cohort of patients who underwent operative without postoperative RT. The event-free survival (EFS) was compared in the two groups.

RESULTS

For the study, 34 patients and 34 matched control subjects were identified. The two groups did not differ in terms of age (p = 0.810), gender (p = 0.328), tumor size (p = 0.803) and margin status (p = 0.799). Patients who received surgery plus RT had a significantly higher 3‑year EFS than those who received surgery alone (74.6% vs. 13.3%, P < 0.001). Factors including postoperative RT and margin status were independent factors of EFS. The values of P were <0.001 and 0.003 and the hazard ratios (95% confidence interval) were 11.929 (4.732-30.072) and 0.299 (0.133-0.671), respectively. None of the patients treated with RT developed serious complications.

CONCLUSIONS

According to our results, postoperative radiotherapy is an effective treatment in desmoid tumors of the neck. Multi-institutional and prospective studies are warranted to further validate our findings.

Prevalence of elastofibroma dorsi on CT: Is it really an uncommon entity?

Objective

The aim of this study was to determine the prevalence, demographic data of elastofibroma dorsi (ED) in adult population who had undergone chest CT examination and to discuss clinical, and radiological presentations, and treatment options of ED.

Methods

We retrospectively reviewed 4074 chest CT examinations for ED from July 2014 to April 2015. Lesion size, side, and patient demographics were analyzed for positive cases of ED. The initial radiology reports of patients with ED were also reviewed.

Results

Of the 4074 patients, 111 patients (2.73%) (77 women and 34 men; mean age: 68.2 years; range: 35–91 years) had a total of 168 ED. The females had a 1.96 -fold higher prevalence of ED than the males (OR, 1.96; 95% CI, 1.481–2.59). The mean lesion thickness was found to be significantly greater in the female patients compared with the male patients (p = 0.001). The prevalence of the disease was estimated to be 4.98 times higher in patients aged 65 years or older (CI 95%, 3.25–7.36). In 111 ED patients, the lesions were only noted in 9 patients' initial radiology report.

Conclusion

Here, we present a prevalence study with the largest population in the literature concerning ED. Our study shows that ED is not as uncommon as previously thought and should be especially suspected in females and older age groups.

Level of Evidence

Level IV, Diagnostic Study.

[Dedifferentiated liposarcoma with inflammatory myofibroblastic tumor-like features: a clinicopathological analysis of five cases]

Objective: To investigate the clinicopathological features, diagnosis and differential diagnosis of dedifferentiated liposarcoma (DDLPS) with inflammatory myofibroblastic tumor (IMT)-like features. Methods: Five cases of DDLPS with IMT-like features were collected from the First Affiliated Hospital of Nanjing Medical University, the Affiliated Hospital of Nanjing University of Traditional Chinese Medicine and the First People's Hospital of Qinzhou between 2013 and 2018. EnVision method and fluorescence in situ hybridization (FISH) were used to detect the immunophenotype of the tumor cells and the profile of MDM2 gene amplification respectively. Results: All five cases were male and the median age was 61 (range 53 to 65) years. The clinical symptoms were mainly related to the space-occupying lesions. The tumors were located in duodenal mesentery (two cases), intestinal wall (one case), retroperitoneum (one case), and spermatic cord (one case). Grossly, the tumors were not well encapsulated, ranging from 3 to 13 cm (median 6.7 cm) in diameter, with tan to gray and firm cut surface. Histologically, the dedifferentiated component closely resembled inflammatory myofibroblastic tumor (IMT), with spindle/polygonal/stellate-shaped cells arranged in storiform, sheet-like, or random pattern, with varying degrees of chronic inflammation and fibrosis. All three major patterns seen in IMT (myxoid, cellular and hypocellular fibrous) were observed, the hypocellular fibrous pattern was the most common. Well-differentiated liposarcomatous component was found in the peripheral areas of all the tumors. One case had high grade dedifferentiated component. Four cases were strongly positive for MDM2 and p16. Two cases were positive for SMA, and one case was focally positive for desmin and one for CD34. None of the cases stained for ALK-1. FISH demonstrated MDM2 gene amplification in all five cases. Clinical follow-ups were available in all five cases and the interval ranged from 3 to 66 months (median 23 months). Two patients developed recurrences and one patient had metastasis. The remaining two patients were alive with no evidence of tumor recurrence at 3 and 14 months after surgery respectively. Conclusions: DDLPS with IMT-like features is a more aggressive neoplasm than its histological mimic (IMT), and should not be misdiagnosed as other intermediate or low-grade malignant tumors, such as IMT, sclerosing liposarcoma, inflammatory liposarcoma, aggressive fibromatosis, solitary fibrous tumors, low-grade myofibroblastic sarcoma, and low-grade fibrosarcoma.

ANGIOMYOMA OF THE UPPER LIP - CASE REPORT AND REVIEW OF THE LITERATURE

A case is presented of upper lip angiomyoma in a 36-year-old man. The tumor was painless, palpable and clinically visible. The operation was performed under local anesthesia in the Outpatient Department. There were no complications during the postoperative course. Current literature on the subject is listed in the introduction, followed by presentation of the case and histologic characteristics of the tumor. This case is described as one of the differential diagnostic possibilities in the diagnosis of soft tissue tumors of the lip. Also, through review of the literature, different clinical appearances of angiomyoma, histologic variations and immunohistochemical characteristics are discussed that can help identify this tumor.

The diagnostic significance of repeat ultrasound-guided biopsy of musculoskeletal soft-tissue lesions with initially inconclusive biopsy results

INTRODUCTION

To determine the diagnostic yield of repeat ultrasound (US)-guided biopsy of musculoskeletal soft-tissue lesions with initially inconclusive biopsy results, and to explore predictive factors for success of repeat biopsy.

MATERIALS AND METHODS

This retrospective study included 42 patients who underwent a repeat (second) US-guided biopsy session to target a musculoskeletal soft-tissue lesion because an initial US-guided biopsy session provided inconclusive results. Both biopsy sessions were performed in a tertiary referral center for soft-tissue sarcomas.

RESULTS

The diagnostic yield of repeat US-guided biopsy was 47.6%. Malignant nature of the lesion (P = 0.031), sharp lesion borders on US (P = 0.011), and good to very good lesion visibility on US (P = 0.017) were significantly associated with a diagnostic repeat US-guided biopsy. There was also a trend towards significance (P = 0.073) for a higher number of biopsy passes through the lesion. Other patient characteristics (age and gender), magnetic resonance imaging features (lesion homogeneity on T1-weighted, T2-weighted, and gadolinium chelate enhanced sequences, borders, enhancement pattern, depth and size), US features (lesion appearance, vascular flow, and depth), biopsy-related factors (days between initial and repeat US-guided biopsy, needle diameter, maximum length of acquired samples), and operator-related factors (same or different radiologists/pathologists for initial and repeat biopsies), were not associated with the diagnostic success of the repeat US-guided biopsy.

CONCLUSIONS

Repeat US-guided biopsy of a musculoskeletal soft-tissue lesion with initially inconclusive biopsy results can be useful to establish a final diagnosis. Lesion features on US (borders and visibility) may be used to prospectively determine the utility of a repeat US-guided biopsy.