Histiocytic sarcoma mimicking localized tenosynovial giant cell tumor in the pediatric foot: A rare case report with MRI Findings.

We present a rare case of histiocytic sarcoma (HS) occurring in the foot of a 12-year-old male, initially misdiagnosed as localized tenosynovial giant cell tumor (TSGCT). HS is an exceptionally uncommon hematologic malignant neoplasm, with its occurrence in children and extranodal sites being even rarer. To our knowledge, this is the first reported case of extranodal HS in the foot, emphasizing comprehensive MRI findings. Initially, the patient was diagnosed with TSGCT based on histological results following surgical resection. However, after recurrence and subsequent surgical resection, histological and immunochemical analyses led to a revised diagnosis of HS. This report focuses on the MRI findings of HS, highlighting the distinctions from localized TSGCT. While both conditions share histopathological similarities, immunohistochemical tests are crucial for accurate diagnosis. The report underscores the importance of differentiating HS for appropriate treatment.

Predictors of Extraprostatic Extension in Patients with Prostate Cancer.

PURPOSE: To identify effective factors predicting extraprostatic extension (EPE) in patients with prostate cancer (PCa). METHODS: This retrospective cohort study recruited 898 consecutive patients with PCa treated with robot-assisted laparoscopic radical prostatectomy. The patients were divided into EPE and non-EPE groups based on the analysis of whole-mount histopathologic sections. Histopathological analysis (ISUP biopsy grade group) and magnetic resonance imaging (MRI) (PI-RADS v2.1 scores [1-5] and the Mehralivand EPE grade [0-3]) were used to assess the prediction of EPE. We also assessed the clinical usefulness of the prediction model based on decision-curve analysis. RESULTS: Of 800 included patients, 235 (29.3%) had EPE, and 565 patients (70.7%) did not (non-EPE). Multivariable logistic regression analysis showed that the biopsy ISUP grade, PI-RADS v2.1 score, and Mehralivand EPE grade were independent risk factors for EPE. In the regression assessment of the models, the best discrimination (area under the curve of 0.879) was obtained using the basic model (age, serum PSA, prostate volume at MRI, positive biopsy core, clinical T stage, and D'Amico risk group) and Mehralivand EPE grade 3. Decision-curve analysis showed that combining Mehralivand EPE grade 3 with the basic model resulted in superior net benefits for predicting EPE. CONCLUSION: Mehralivand EPE grades and PI-RADS v2.1 scores, in addition to basic clinical and demographic information, are potentially useful for predicting EPE in patients with PCa.

Fibrosarcoma of Great Toe Shown with Multimodality Radiologic Imaging Features.

INTRODUCTION: Fibrosarcoma of bone is a rare malignant spindle cell tumor. CASE STUDY: Herein, we present a case of fibrosarcoma in a 40-year-old male who was presented to the clinic with left-sided great toe pain for 20 years. Simple radiographs showed acrolysis at the distal phalanx of great toe. Magnetic resonance imaging (MRI) revealed a 1.5 cm sized heterogenous high signal intensity mass on T2-weighted images and iso signal intensity on T1- weighted images. Dorsal and distal portion of the mass showed markedly dark signal intensity on T1 and T2-weighted images. CONCLUSION: In an enhanced image, the mass showed heterogenous enhancement. Surgical removal was performed and pathologic analysis revealed fibrosarcoma. Although extremely rare, fibrosarcoma of the bone should be kept in mind as a possibility when a lesion exhibits a black signal intensity component on an MRI with acrolysis.

MRI Findings of Periarticular Lesions with Isolated Greater Tubercle Fractures and Dislocation.

PURPOSE: To identify MRI findings for injuries to periarticular soft tissue structures that were related to isolated greater tubercle fracture. MATERIALS AND METHODS: 16 patients (mean age: 53.8, range 30-71 yrs) were enrolled and diagnosed with isolated greater tubercle (GT) fracture with CT and MRI and underwent shoulder arthroscopy from September 2009 to April 2019. Two musculoskeletal radiologists were blinded to the patient history and arthroscopic surgical findings and reviewed patient's CT and MRI. Fracture displacement, fracture center, and presence of bony Bankart lesion with Hill sachs lesion were checked on shoulder CT. Soft tissue injuries, including rotator cuff injury, deltoid muscle injury, long head of biceps tendon injury, capsular injury, glenoid injury, and injury location of the subscapularis and infraspinatus were checked on shoulder MRI. RESULTS: MRI showed supraspinatus injury (56.3%), subscapularis injury (56.3%), deltoid muscle injury (25%), infraspinatus injury (25%), teres minor muscle injury (37.5%), injury of the long head of the biceps tendon (43.8%), inferior glenohumeral ligament tear (87.5%), superior labral anterior-toposterior lesion (25%), Bankart lesion (18.8%), and Hill-Sachs lesion (6.3%). 88.9% of subscapularis injuries and 75% of infraspinatus injuries showed caudal predominance. All of the patients with infraspinatus injuries showed concomitant teres minor muscle injuries. In order of frequency, the fracture centers were anterior (25%), posterior (31.3%), and all (43.8%). For patients with Bankart and Hill- Sachs lesions, the fracture center included the posterior portion in all cases. CONCLUSION: MRI and active arthroscopic examinations may be valuable when an isolated GT avulsion fracture is identified on X-ray examination.

Extradural Spinal Lymphoplasmacyte-Rich Meningioma in the Thoracic Spine: A Case Report and Literature Review.

Most spinal meningiomas have an intradural or partly extradural location. The meningothelial origin is the most common pathologic type of spinal meningioma. Pure extradural spinal meningiomas are not common, and lymphoplasmacyte-rich meningioma (LPRM) is very rare. We report a case of isolated extradural spinal meningioma in the thoracic spine that was pathologically confirmed as LPRM.

Extra-Abdominal Desmoid-Type Fibromatosis Mimicking Myxofibrosarcoma.

A 27-year-old woman was confirmed to have extraabdominal desmoid-type fibromatosis. Desmoid-type fibromatosis is a very rare connective tissue neoplasm with the extraabdominal type even more rare. It is most commonly found in proximal structures such as shoulders, neck, chest, and extremities. There are few case reports for desmoid-type fibromatosis located in paraspinal soft tissue. We report a case of desmoid-type fibromatosis mimicking a myxofibrosarcoma. Teaching Point: Even if there are suggestive findings for malignant soft tissue tumor on radiologic evaluation, histological confirmation is necessary before surgical treatment.

Intraosseous ganglion cyst mimicking chondrosarcoma on MRI: a case report.

BACKGROUND: The intraosseous ganglia is a benign cyst, rarely locate in the olecranon process. As intraosseous ganglia can mimic malignant bone tumor, computed tomography (CT) is important for diagnosis even when magnetic resonance imaging (MRI) suggests malignant bone tumor, such as chondrosarcoma. CASE PRESENTATION: In this paper, we report a 42-year-old woman with intraosseous ganglia in the olecranon process of the ulna. She complained pain in right elbow for 3 weeks. MRI revealed an intraosseous mass which initially diagnosed as chondrosarcoma. However, followed computed tomography (CT) demonstrated scattered intralesional gas and no underlying mineralization, and we can exclude chondrosarcoma from diagnosis. CONCLUSIONS: The intraosseous ganglia can mimic bone tumor in MRI; therefore, CT is essential for accurate characterization of bone tumor. Even if MR imaging strongly suggests chondrosarcoma of the bone, CT should be performed as additional study.

Early Imaging Findings of Hypertrophic Osteoarthropathy Mimicking Bone Metastasis from Extrathoracic Malignancy.

Hypertrophic osteoarthropathy (HOA) is a syndrome characterized by digital clubbing, periosteal bone formation, and synovial effusions. Secondary HOA is associated with intrathoracic malignancy in most cases; however, in rare cases, HOA can be caused by extrathoracic conditions. We report early ultrasound, computed tomography, magnetic resonance imaging, and bone scintigraphy findings of HOA in a patient with breast cancer. Its ambiguous clinical and imaging findings that mimicked malignant conditions are particularly interesting and informative.

Primary neuroendocrine carcinoma of the breast: radiologic and pathologic correlation.

Primary neuroendocrine carcinoma of the breast (PNCB) is a rare type of breast cancer. There have been few reports on PNCB and radiologic-pathologic correlation in PNCB has not been described thoroughly. We present a rare case of pathologically confirmed poorly differentiated PNCB removed via lumpectomy. Image findings on mammography, ultrasonography, computed tomography, magnetic resonance image, and positron emission tomography-computed tomography are also presented.