Ultrasonographic evaluation of thoracic and abdominal neoplasia in domestic ruminants: A systemic review

Abstract

There is a lack of literature on the usefulness of ultrasonography in the diagnosis and prognosis of thoracic and abdominal neoplasia in domestic ruminants, such as cattle, camels, sheep, and goats. This review aims to shed light on the current applications and prospects of ultrasonography in the diagnosis of thoracic and abdominal neoplasia in domestic ruminants. The scientific literature on ultrasonographic evaluation of the thoracic and abdominal neoplasia in domestic ruminants has been systematically reviewed to verify the potential role of ultrasonography in diagnosing such neoplasia. Based on the literature results, cattle (71.03%) were the most affected animals by thoracic and abdominal neoplasia, followed by sheep (11.86%), goats (11.57%), and camels (5.54%). In all included species, the abdominal neoplasia was more frequent (6.18%) than the thoracic neoplasia (2.97%), and the most frequent neoplasms were forestomach neoplasia. It is concluded that ultrasonography is not widely used in diagnosing thoracic and abdominal neoplasia in ruminant practice. Using ultrasonography in conjunction with guided needle aspiration and biopsy can offer veterinarians the opportunity for more precise diagnosis and treatment decisions guidance of thoracic and abdominal neoplasia in domesticated ruminants.

Keywords: Animals; Diagnosis; Ruminant; Tumors; Ultrasound.

Fig. 1.. Ultrasonograms in a Holstein cow with mesothelioma (3.5 MHz). Image (A) shows the ultrasonographic appearance of the greater omentum viewed at the left ventral abdomen. The greater omentum is surrounded by hypoechoic ascitic fluid and contains multiple nodules (arrow). Image (B) shows the ultrasonographic appearance of the lateral aspect of the abdomen taken at the right 11th intercostal space where multiple coalesced nodules (arrowhead) were scanned floating in hypoechogenic fluid. Image (C) shows multiple nodules in the greater omentum, varying in size from one to ten cm. Image (D) shows numerous masses adherent to the epicardium. Image (E) shows tubular structures lined by neoplastic cells with basophilic cytoplasm and supported by connective tissue; magnification (HE, x40). Image (F) shows the lumina of the tubular structures are lined by solitary columnar neoplastic mesothelial cells with basophilic cytoplasm; magnification (HE, ×200) (Tharwat et al., 2012).

Fig. 2.. Longitudinal sonogram of an omasal leiomyoma imaged at the seventh intercostal space in a 6-year-old Holstein cow. Note the asymmetric, non-homogenous, and echogenic patterns of the tumor (A). The mass appeared to project into the omasal lumen. Image (B) shows necropsy findings in the same cow showing an 18×14 cm mass in the omasum. Image (C) shows a photomicrograph of a section of the mass revealing interlacing bundles of well-differentiated smooth muscle cells with abundant cytoplasm and irregular fusiform nuclei with vesiculated chromatin (Hematoxylin and eosin ×40). Lt, lateral; Md, medial, 1, right ventral thoracic wall; 2, sternal part of the diaphragm and peritoneum; 3, liver; 4, omasal wall, 5, omasal lumen (Mohamed et al., 2004).

Fig. 3.. Intraoperative ultrasonographic findings of the abomasum in a female camel with inappetence and colic during the past 6 months. In image (A), the abomasal wall appeared thickened, vascularized, and hyperechoic and the contents appeared heterogeneous (B). At necropsy, the abomasal (C) and omasal (D) folds were thickened, congested, and ulcerated. The tumor consisted of variable-sized acini lined by malignant epithelial cells with moderate atypia separated by desmoplastic stroma with dense mixed inflammatory cell infiltrate. Extensive areas of necrosis with suppuration were also seen (HE: (E) ×200; (F) ×400) (Tharwat et al., 2018).

Fig. 4.. Transrectal ultrasonographic findings in a female camel with renal cell carcinoma of the right kidney. Image (A) shows a hypoechoic mass involving the right renal parenchyma while image (B) shows the normal left kidney. Postmortem findings showed that the right kidney occluded almost the pelvic cavity (C) and a severely enlarged right kidney (18 Kg) compared to a normal, 1.5 Kg, left kidney (D). Image (E) shows cross section through the right kidney mass with a hemorrhagic, irregular shaped, and cavitated tumor. Image (F) shows histopathological results of the tumor revealing tubular differentiation with malignant epithelial lining and nuclear anaplasia (HE ×400) (Tharwat et al., 2017).