title: Comparison of abdominal ultrasound and magnetic resonance imaging for detection of abdominal lymphadenopathy in dogs with metastatic apocrine gland adenocarcinoma of the anal sac.
abstract: Imaging studies in humans with anal and rectal cancer indicate that magnetic resonance imaging (MRI) is a more sensitive technique than abdominal ultrasound (AUS) for the detection of abdominal lymphadenopathy. The purpose of this retrospective study was to directly compare the efficacy of these two techniques in detecting abdominal lymphadenopathy in dogs with apocrine gland adenocarcinoma of the anal sac (AGAAS). Six dogs with histologically confirmed AGAAS and histopathologic confirmation of metastasis to abdominal lymph nodes (LNs) had AUS and abdominal MRI. AUS identified lymphadenopathy in two of six dogs, whereas MRI identified lymphadenopathy in all the six dogs. Lymphadenopathy was predominantly sacral in location, with involvement of the medial iliac and hypogastric LNs in only two cases. These data suggest that MRI is more sensitive than AUS for detecting sacral abdominal lymphadenopathy in dogs with AGAAS. As such, MRI could be considered in any patient with AGAAS for initial staging of this disease.
authors: Department of Oncology, VCA Alameda East Veterinary Hospital, Denver, CO, USA.
authors: C L
authors: CL
authors: Anderson
authors: Department of Environmental & Radiological Health Sciences, Colorado State University, Fort Collins, CO, USA.
authors: C S
authors: CS
authors: MacKay
authors: Department of Veterinary Clinical Sciences, Washington State University, Pullman, WA, USA.
authors: G D
authors: GD
authors: Roberts
authors: Department of Veterinary Clinical Sciences, Washington State University, Pullman, WA, USA.
authors: J
authors: J
authors: Fidel
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis / Q000473:pathology / Q000662:veterinary*; D000694:Anal Gland Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D000695:Anal Sacs / Q000000981:diagnostic imaging / Q000473:pathology; D000818:Animals; D001050:Apocrine Glands / Q000000981:diagnostic imaging / Q000473:pathology; D004283:Dog Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D004285:Dogs; D008206:Lymphatic Diseases / Q000000981:diagnostic imaging / Q000473:pathology / Q000662:veterinary*; D008207:Lymphatic Metastasis; D008279:Magnetic Resonance Imaging / Q000662:veterinary; D012189:Retrospective Studies; D014463:Ultrasonography / Q000662:veterinary
keywords: apocrine gland adenocarcinoma of the anal sac; canine; lymphadenopathy; magnetic resonance imaging; metastasis; ultrasonography