Multicystic peritoneal tumor in two layer hens

Our plain-English summary of Multicystic peritoneal tumor in two layer hens, by K. Yoshida, T. Miyoshi, T. Murakami (The Journal of Veterinary Medical Science, 2020).

The study

• Authors: K. Yoshida, T. Miyoshi, T. Murakami
• Journal: The Journal of Veterinary Medical Science
• Published: 2020;82(3):294-298
• Type of article: Case report
• Cited by: 1 article, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

In chicken, peritoneal cystic lesions have not been clearly categorized. In this study, diffuse peritoneal multiple cysts were observed in two layer hens. The cysts in the serosa were lined with single layers of squamous or cuboidal cells. The papillary proliferations of columnar cells were also observed in one case. The smooth muscle layer or mass were observed around the cysts in both cases. The cystic lining cells were positive for pan-cytokeratin, vimentin, S100 and Wilms tumor 1. Ultrastructurally, they had sparsely microvilli on the luminal surface. The histological results indicated the present cases were multicystic mesothelioma, but also had characteristics of Mullerian epithelium. This is the first report describing the detailed pathological feature of unique multicystic tumor in chicken.

In plain English

This veterinary case report described two white leghorn layer hens in Japan with many small cysts in the lining of the abdomen (the peritoneum). The cysts were found by chance at routine meat inspection. The hens came from different farms, and their age was uncertain. Organs in both hens were covered with clear cysts less than 1 cm across. Under the microscope, the cysts were lined by a single layer of cells. No cell division and no invasion into organs were seen. Staining showed the cells were positive for cytokeratin and vimentin. Calretinin stained the cell surface but not the nucleus. A smooth muscle layer surrounded the cysts. No avian leukosis virus was detected. The authors concluded the tumors were likely benign mesothelioma but also had features of Mullerian epithelium. They stated that telling these two apart was difficult in this study and that more cases are needed. The article does not mention asbestos or any fiber exposure.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Veterinary case report (pathology description of two cases)
• Who was studied: Two white leghorn layer hens (case 1 and case 2) from different farms, found at routine chicken meat inspection in Japan. Age uncertain, estimated at about 600 to 700 days.
• Exposure: No asbestos or other fiber exposure was studied. The hens were tested for avian leukosis virus (ALV), which is linked to earlier chicken mesotheliomas. No virus or virus-like particles were found, and the authors suggested the tumors might be spontaneous.
• Main results:
  • In both hens, the abdominal organs were covered with multiple transparent cysts less than 1 cm in diameter. Case 1 had more cysts than case 2.
  • Case 1 showed scattered papillary (finger-like) growths of small column-shaped cells. Case 2 did not.
  • In both hens, the tumors stayed within the serous membrane and did not invade organ tissue.
  • In both hens, the tumor cells were strongly positive for cytokeratin and vimentin.
  • Calretinin stained the cell surface strongly but was negative in the nucleus.
  • In both hens, the tumor cells were negative for smooth muscle actin, neuron specific enolase, progesterone receptor, estrogen receptor and ALV.
  • A smooth-muscle-actin-positive layer surrounded the cysts. It was more prominent in case 2.
  • Under the electron microscope, the cells had sparse microvilli on their surface. No cilia were found in either case.
• The authors' conclusion: The authors concluded that the tumors were likely benign mesothelioma but showed notable differences from mesothelioma, including features of Mullerian epithelium.
• Limitations the authors state:
  • The authors stated that distinguishing benign mesothelioma from a Mullerian epithelial tumor was difficult in this study.
  • The authors stated that further case studies in chickens are needed for a definite diagnosis.
  • The ages of the hens were uncertain and only estimated.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Mesothelioma, Peritoneal mesothelioma.

Medical terms in this study, explained in our Lexicon: Columnar Cell, Wilms Tumor 1 (WT-1), Multicystic Mesothelioma (MCM), Epithelium.

Related studies

• Benign multicystic mesothelioma and peritoneal inclusion cysts: are they the same clinical and histopathological entities? A systematic review to find an evidence-based management — A.M.C. Rapisarda, A. Cianci, et al. (2018)
• Intra-abdominal benign multicystic peritoneal mesothelioma — I. Jouvin, A. Dohan, et al. (2014)
• Cytomorphologic characteristics of fine needle core biopsy of multicystic peritoneal mesothelioma: a case report and review of the literature — A.M. Kemp, R. Nayar, et al. (2010)
• Multicystic mesothelioma with endometriosis — G.M. Groisman, H. Kerner (1992)
• A multicystic tumor causing intermittent pain in a young man — E.V. Madsen, I.H. de Hingh (2014)
• Multi-institutional experience of diffuse intra-abdominal multicystic peritoneal mesothelioma — T.C. Chua, T.D. Yan, et al. (2011)

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