Role of magnetic resonance imaging in the prediction of histological grade in soft tissue sarcomas

BACKGROUND

Soft tissue sarcomas are rare malignant tumors with significant heterogeneity. The importance of classifying histological grades is fundamental to defining the treatment approach.

OBJECTIVE

To evaluate magnetic resonance imaging (MRI) in predicting the histological grade of soft tissue sarcomas.

METHODS

A retrospective observational study included patients over 18 years undergoing MRI and primary tumor surgery at AC Camargo Cancer Center from January 2015 to June 2022. Two radiologists evaluated MRI criteria (size, margin definition, heterogeneity of the T2 signal, high-intensity peritumoral signal on T2, and postperitumoral contrast), and a grading prediction score was calculated. χ2 and logistic regression analyses were conducted.

RESULTS

Sixty-eight patients were included (38 men; median: 48 years). Moreover, 52 high-grade and 16 low-grade tumors were observed. The MRI criteria associated with histological grade were peritumoral high-intensity T2-weighted signals (p < 0.001) and peritumoral postcontrast enhancement (p = 0.006). Logistic regression confirmed their significance (odds ratio [OR]: 11.8 and 8.8, respectively). Each score point increment doubled the chance of high-grade tumors (OR: 2.0; p = 0.014).

CONCLUSION

MRI effectively predicts histological grades of soft tissue sarcomas. Peritumoral high-intensity T2-weighted signals and peritumoral postcontrast enhancement are valuable indicators of high-grade tumors. This highlights MRI's importance in treatment decision-making for sarcoma patients.

Primary bone lymphoma: pictorial essay

Primary bone lymphoma is a rare neoplasm that can initially present as local pain, a palpable mass, and pathologic fracture. It can also be discovered as an incidental finding on an imaging examination. It is defined as a bone marrow tumor with no involvement of other sites, lasting at least six months. The diagnosis is confirmed by biopsy and immunohistochemical analysis. Although the imaging characteristics are nonspecific, there are certain findings that, when correlated with clinical and epidemiological aspects, can increase the level of suspicion of primary bone lymphoma. The classic imaging aspect is a bone lesion with a soft-tissue component that preserves the cortical layer more than would be expected given the invasive nature of the lesion. Magnetic resonance imaging is the best imaging method to evaluate the extent of involvement of adjacent compartments, whereas computed tomography depicts the cortical layer in greater detail, as well as being an important tool for biopsy guidance. Other imaging modalities are also discussed, such as X-ray, ultrasound, bone scintigraphy, and positron emission tomography/computed tomography. The aim of this paper is to describe the most common findings obtained with the various imaging methods used in patients with a confirmed diagnosis of primary bone lymphoma.

Snapping scapula syndrome: pictorial essay

Snapping scapula syndrome manifests as an audible or palpable crackling during the sliding movements of the scapula over the rib cage, often perceived during physical or professional activities. It can be caused by morphological alteration of the scapula and rib cage, by an imbalance in periscapular musculature forces (dyskinesia), or by neoplasia (bone tumors or soft tissue tumors). In this pictorial essay, we review the main causes of snapping scapula syndrome, exemplified by a collection of didactic cases.

Lipoma arborescens of the elbow: a case with features of a high-grade tumor

Lipoma arborescens (LA) is an uncommon non-neoplastic disorder that may affect almost any joint, mainly the knee. LA is very rare in the elbow, and there are only a few cases reported in the literature. This study aimed to describe a case of LA in the elbow, presenting with features of a high-grade tumor. The authors report the case of a 51-years-old male who presented to this institution with pain and swelling on the left elbow. The patient had a seven-year history of investigation, with inconclusive diagnosis. Magnetic resonance imaging (MRI) showed an expansive mass with local aggressiveness. Due to these characteristics, it was not possible to discard soft tissue sarcoma at the differential diagnosis. After biopsy and a multidisciplinary team meeting, the authors opted for surgical resection. The final anatomopathological result confirmed the diagnosis of LA. Despite not being a true neoplasm, LA can cause many symptoms and functional impairment of the affected joint. It is important to keep this diagnosis in mind when any expansive mass surrounding a joint is observed.

Incidência e aspectos de imagem do linfoma pós-transplante hepático em crianças

OBJETIVO: Avaliar a incidência e os aspectos de imagem do linfoma pós-transplante hepático em crianças. MATERIAIS E MÉTODOS: Foram revisados os prontuários e exames de imagem de crianças submetidas a transplante hepático entre 2000 e 2008 em uma única instituição. RESULTADOS: De 241 crianças submetidas a transplante hepático, com seguimento médio de 41,4 ± 26,4 meses, 16 (6,6%) tiveram linfoma. A média de idade no transplante hepático das crianças que desenvolveram linfoma foi inferior à das crianças que não desenvolveram (23,9 ± 18,9 vs. 38,0 ± 48,9 meses; p = 0,02). O tempo entre o transplante e o desenvolvimento do linfoma variou de 6 a 103 meses. A apresentação clínica e radiológica foi variável e a localização mais comum do tumor foi no abdome (n = 13; 81,3%), seguida de tórax e cabeça e pescoço (n = 4; 25,0% cada). Os achados de imagem incluíram: linfonodomegalias, massas mediastinais, pulmonares e mesentéricas, espessamento parietal de alças intestinais e nódulos hepáticos e renais. Quatro crianças (25,0%) faleceram devido a complicações do linfoma. CONCLUSÃO: Linfomas são complicações relativamente incomuns e potencialmente fatais que podem acontecer a qualquer momento após o transplante hepático em crianças, e que têm diversas apresentações clínicas e de imagem.