Three cases of hydatid disease are reported, all presenting as soft tissue lesions in the lower extremities. All three cases were studied with ultrasound (US), two with computed tomography (CT), and two with magnetic resonance (MR) imaging techniques. Two patients presented with multivesicular lesions which were considered diagnostic of hydatid disease. The third patient showed a lesion with a predominantly solid pattern, closely mimicking a soft-tissue neoplasm. US was not diagnostic, but MR outlined vesicular structures and a fibrous pericyst. Hydatid disease presenting in the soft tissues can therefore be diagnosed with confidence when it shows multivesicular lesions but MR may be the most useful imaging technique when a complex or solid pattern is present.

Chemical shift GRE MR imaging can be used to detect fatty metamorphosis in HCC.

OP GRE sequences could replace conventional SE sequences in T1-W imaging in nonfatty livers, whereas in fatty livers, T1-W SE sequences could be obviated, but both OP and IP sequences are necessary. Chemical shift imaging (OP and IP) can be used to accurately characterize lesions for fat content.

Renal lymphangiectasia is a rare benign condition of the kidney without specific clinical presentations. Classic imaging findings are described in literature. Here, we present a case of renal lymphangiectasia with history of bilateral flank pain and abnormal renal function tests. The radiological appearance on ultrasound (US) and computed tomography (CT) showed features of bilateral renal lymphangiectasia but the patient refused invasive procedure for aspiration of the cysts. So, follow-up of the patient was done by magnetic resonance imaging (MRI). Imaging findings of our case on US, CT, and MRI are discussed along with details of the additional finding of dilated retroperitoneal lymphatic channels, cisterna chyli, as well as the thoracic duct.

Peripheral nerve sheath tumors (PNSTs) in domestic and wild animals are uncommon tumors that originate from cells that comprise the sheaths of peripheral nerves. One type of PNST originates from Schwann cells and is termed schwannoma. Two other types of cells, perineural cells and fibroblasts, are components of peripheral nerve sheaths and may give rise to tumors. These tumors, particularly the malignant variety, may have histologic patterns that closely mimic those of other fusiform tumors. Electron microscopic and/or immunohistochemical evaluation is often necessary to establish a diagnosis of PNST. 11,13 PNSTs affecting cranial or spinal nerve roots and the brachial plexus have been described in several animal species (cattle, dog, cat, rat). 11 Malignant cranial and spinal PNSTs are rare in animals and metastasize infrequently. 3,11 In this report, a malignant PNST originating from a spinal nerve with hepatic and splenic metastasis is described in a snake.A 12-year-old captive-bred male water moccasin (Agkistrodon piscivorus) developed a firm nonulcerated and progressive swelling of the subcutaneous tissue on the right midbody. Flaccid paralysis and lack of propriocepcion was present distal to the lesion. The head and neck were displaced laterally to the left. The snake was anesthetized using a face mask with isofluorane a in oxygen for induction followed by tracheal intubation. A biopsy of the costal mass was obtained for evaluation. The histopathologic diagnosis was invasive undifferentiated spindle cell sarcoma. Neoplastic cells were observed in all the sample edges. The animal was again anesthetized to completely resect the cutaneous mass. The previous diagnosis was histologically confirmed, and neoplastic cells were observed in the deeper resection border associated with the ribs.Three months later, a new and larger subcutaneous swelling was observed in the same location. The snake's general condition had markedly worsened: it was anorectic and the head displacement, flaccid paralysis, and lack of propriocepcion were more pronounced. The animal was again anesthetized and positioned in sternal recumbency to evaluate the extension of the new lesion and to detect possible metastasis by radiography and magnetic resonance imaging (MRI). Plain radiographs revealed a large, poorly defined soft tissue mass on the right costal wall that invaded the celomic cavity. On MRI, transverse sections revealed a hyperintense mass on the right side of the body. The mass was located in the paravertebral muscles and invaded the celomic cavity through the intercostal spaces. It also invaded the vertebral canal through intervertebral foramina and compressed the spinal cord (Fig. 1). Coronal sections demonstrated neoplasFrom the Department of Pathology (Ramis, Pumarola, Majó) and the Veterinary Teaching