BACKGROUND Peritoneal mesothelioma is a rare abdominal disease; that occasionally occurs congenitally in younger calves. Cytologic examination of peritoneal effusion (PE) was utilized to diagnose this disease, and was not diagnostic. Diagnostic accuracy has been elevated by recent use of ultrasonography (US), despite most diagnoses have been obtained post-mortem in slaughter houses or during clinical necropsy. In humans, ante-mortem diagnosis is highly associated with clinical use of computed tomography (CT) and laparoscopy together with imaging-assisted biopsy. The present report evaluates the diagnostic applicability of CT and laparoscopy as well as US via the practical application of these imaging modalities in an affected calf, and compares the cytologic and histologic findings among in PE, and specimens obtained from fine-needle aspiration and core-needle biopsy. In addition, the present results were reviewed in comparison with those of previous bovine and human reports. CASE PRESENTATION A 58-day-old male Japanese black calf presented first with scrotal swelling, followed by progressive abdominal distention. Abnormalities of the case included: 1) accumulation of anechoic PE inside the swollen scrotum and abdomen; 2) formation of multiple echogenic nodules within the peritoneal membrane based on US images; 3) presence of hyper-dense spots (suspected calcification) along the margins of the nodules; 4) anatomic connections between intra-abdominal nodular lesions and the swollen tunica vaginalis via the inguinal region based on CT images; 5) serosanguineous-colored and less-turbid characteristics of PE; and 6) formation of multiple nodules over all of the serosa of the rumen as well as the peritoneal wall based on laparoscopic views. Fine-needle aspiration and core-needle biopsy were successfully performed under US and laparoscopic observations, respectively. Histology findings of the core-needle biopsy specimen appeared more indicative (characterization of tubular structures comprised of cubical or columnar abnormal mesothelial cell linings) diagnostically of peritoneal mesothelioma than did findings of the fine-needle aspiration specimen. CONCLUSIONS To the best of our knowledge, this report is the first description of clinical applications of CT and laparoscopy to diagnose peritoneal mesothelioma in a calf. Laparoscopy enhanced the diagnostic accuracy due to clear gross visualization of the intra-abdominal abnormalities and applicability to imaging-guided core-needle biopsy.

中文翻译：

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影像学和活检方法对小牛腹膜间皮瘤的诊断功效。

背景腹膜间皮瘤是一种罕见的腹部疾病。这种情况偶尔发生在年轻的犊牛中。腹腔积液（PE）的细胞学检查可用于诊断该疾病，但不能诊断。尽管大多数诊断是在屠宰场或临床尸检期间进行的验尸，但最近通过使用超声检查（US）已经提高了诊断的准确性。在人类中，事前诊断与计算机断层扫描（CT）和腹腔镜检查以及影像辅助活检的临床应用高度相关。本报告通过这些影像学方法在患病小牛中的实际应用，评估了CT和腹腔镜以及US的诊断适用性，并比较了PE中的细胞学和组织学发现，以及从细针穿刺和芯针活检获得的标本。此外，目前的结果与以前的牛和人类报告进行了比较。病例介绍一只58日龄的雄性日本黑小牛首先出现阴囊肿胀，然后逐渐进行腹胀。该病例的异常包括：1）消声的PE在阴囊和腹部肿胀内积聚；2）基于US图像在腹膜内形成多个回声结节；3）结节边缘存在高密度斑点（可疑钙化）；4）基于CT图像，通过腹股沟区域将腹腔内结节性病变与阴道中膜肿胀之间的解剖学联系；5）PE呈血色和较不混浊的特性；6）根据腹腔镜观察，在瘤胃的所有浆膜以及腹膜壁上形成多个结节。在美国和腹腔镜观察下，分别成功进行了细针穿刺和芯针活检。与细针穿刺标本的发现相比，在诊断腹膜间皮瘤时，核心针穿刺活检标本的组织学发现似乎更具指示性（由立方或柱状异常间皮细胞内膜组成的管状结构的特征）。结论据我们所知，本报告首次描述了CT和腹腔镜诊断小腿腹膜间皮瘤的临床应用。