Ultrasonographic characteristics of soft tissue tumours in dogs

B-Mode and Contrast-Enhanced Ultrasonography Aspects of Benign and Malignant Superficial Neoplasms in Dogs: A Preliminary Study

Simple Summary

In dogs, superficial neoplasms are common, and it is crucial to determine their malignancy, as this will have an impact on treatment and prognosis. So far, the diagnostic value of ultrasound modalities, such as B-mode and contrast enhanced ultrasound, for superficial neoplasms in dogs is still unclear, despite promising studies in humans. B-mode ultrasound enables assessment of the size, shape and arrangement of the neoplastic tissue, whereas contrast enhanced ultrasound enables the assessment of blood flow intensity and pattern. The aim of this study was to identify B-mode and contrast enhanced ultrasound characteristics that may be used to distinguish benign and malignant superficial neoplasms in dogs. Ultrasonographic characteristics, for which a significant difference was observed between benign and malignant neoplasms, were border definition, echogenicity, echotexture, blood flow pattern at wash-in and blood flow intensity during wash-out at the center of the neoplasm. Despite these significant differences, there was a considerable overlap in ultrasonographic characteristics between benign and malignant neoplasms. In conclusion, B-mode and contrast enhanced ultrasound might contribute to malignancy prediction; however, based on individual ultrasonographic characteristics, they seem unable to replace cytology or histopathology.

Abstract

Contrast-enhanced ultrasonography (CEUS) is considered a promising technique for differentiation of benign and malignant tumors in humans. However, few studies have assessed superficial neoplasms in dogs by means of CEUS. The aim of this study was to identify ultrasonographic criteria evaluated by B-mode ultrasound (US) and CEUS that may be used to distinguish benign and malignant superficial neoplasms in dogs. A total of 63 superficial neoplasms from 59 dogs were evaluated using B-mode US and CEUS prior to histopathologic examination. Qualitative and quantitative parameters were compared between benign and malignant neoplasms by Fischer’s exact test or fixed effects model. With B-mode US, a significant difference was found for border definition, echogenicity and echotexture. With CEUS, a significant difference was found for the enhancement pattern at wash-in and the wash-out area under the curve at the center of the neoplasm. Malignant neoplasms had on average a lower regional blood volume during the wash-out phase compared to benign neoplasms. Despite these significant differences, there was a considerable overlap in B-mode and CEUS parameters between benign and malignant neoplasms. In conclusion, B-mode US and CEUS might contribute to malignancy prediction; however, based on individual ultrasonographic parameters, they seem unable to replace cytology or histopathology.

Malignancy prediction of cutaneous and subcutaneous neoplasms in canines using B-mode ultrasonography, Doppler, and ARFI elastography

BACKGROUND

Cutaneous and subcutaneous neoplasms are highly prevalent in dogs, ranging from benign to highly aggressive and metastatic lesions. The diagnosis is obtained through histopathology, however it is an invasive technique that may take a long time to obtain the result, delaying the beginning of the adequate treatment. Thus, there is a need for non-invasive tests that can help in the early diagnosis of this type of cancer. The aim of this study was to verify the accuracy of B-mode ultrasonography, Doppler, and ARFI elastography to predict malignancy in cutaneous and subcutaneous canine neoplasms. In addition, we aim to propose an ultrasonography evaluation protocol and perform the neoplasms characterization using these three proposed techniques.

RESULTS

Twenty-one types of specific neoplasm were diagnosed, and using B-mode, we verified the association between heterogeneous echotexture, invasiveness, presence of hyperechoic spots, and cavity areas with malignancy. An increased pulsatility was verified in malignant neoplasms using Doppler (cut-off value > 0.93). When using the elastography, malignancy was associated with non-deformable tissues and shear wave velocity > 3.52 m/s. Evaluation protocols were proposed associating 4, 5, 6, or 7 malignancy predictive characteristics, and characterization was done for all tumors with at least two cases.

CONCLUSIONS

We concluded that ultrasonography methods are promising and effective in predicting malignancy in these types of tumors, and the association of methods can increase the specificity of the results.

Recurrent and non-recurrent feline injection-site sarcoma: computed tomographic and ultrasonographic findings

OBJECTIVES

This study describes the sonographic and computed tomographic (CT) characteristics of primary and recurrent feline injection-site sarcomas (FISSs).

METHODS

Between 2005 and 2013, 32 cats were selected for prospective and retrospective studies. Tumor shape and margins, presence of thickening of the adipose tissue, muscular and bone involvement, pre- and postcontrast attenuation, blurring of fat planes, calcification and liquefactive necrosis, intratumoral areas and skip metastasis were analyzed in CT scans. Echogenicity, echotexture, tumor margins and peritumoral tissue characteristics were analyzed by ultrasound (US).

RESULTS

Irregular shape (62.5%) with digitiform projections (100.0%), mixed (peripheral and intratumoral) contrast enhancement (67.7%), blurring of fat planes (68.8%) and signs of liquefactive intratumoral necrosis (68.8%) were the prevailing CT findings. Ultrasonography revealed irregular tumor margins, peripheral hyperechoic capsule-like rim, heterogeneous echotexture, and hyperechoic tissue contiguous with the formations and thickening of adjacent subcutaneous tissues in all cases. Mixed echogenicity with areas suggestive of tumor liquefactive necrosis was documented in 83.3% of cases. Skip metastases were highly correlated with tumor recurrence (P = 0.001). The incidence of muscular involvement tended to be higher (P = 0.003) in tumors presenting with thickening of adjacent adipose tissue.

CONCLUSIONS AND RELEVANCE

CT and US features common to FISS lesions were highlighted in this study. The imaging modalities employed allowed assessment of peritumoral inflammation, particularly adipose tissue inflammation. Imaging data may contribute to FISS diagnosis, therapeutic planning and patient follow-up.