Case report: Abdominal mesothelioma in Atelerix albiventris

Our plain-English summary of Case report: Abdominal mesothelioma in Atelerix albiventris, by I. Troncoso, J. Brown, C. Isla, et al (Frontiers in Veterinary Science, 2024).

The study

• Authors: I. Troncoso, J. Brown, C. Isla, J.M. Lajara, M. Ebner, K. Fehrmann-Cartes
• Journal: Frontiers in Veterinary Science
• Published: 2024;11:1341815
• Type of article: Case report
• Read it: PubMed · Publisher · Free full text

Abstract

Hedgehogs, as exotic species, are more susceptible to various neoplastic conditions affecting diverse bodily systems, particularly the tegumentary, hemolymphatic, and digestive systems. Among these conditions, epithelial tumors are the most prevalent, followed by round cell tumors and mesenchymal tumors. A striking characteristic is the malignant nature of over 8% of these tumors, leading to a generally unfavorable prognosis. This study aims to present a unique case involving a 2.5 year-old male African pygmy hedgehog in Concepción, Biobío District, Chile, diagnosed with a mesenchymal neoplasia originating from mesothelial cells. The hedgehog presented to the veterinary clinic with acute abdominal pain, prompting ultrasound imaging, and comprehensive cytological, histopathological, and immunohistochemical analyses. During abdominal ultrasound, a mass was observed, and its cytological examination revealed the presence of malignant cells. The histopathological examination unveiled a diffuse mesothelial cell tissue interwoven with abundant fibrous tissue and small cysts containing serous fluid, all enveloped by flattened or cuboidal cells of mesothelial origin. Immunohistochemistry further confirmed the diagnosis, demonstrating positive immunostaining for calretinin and mesothelin markers, corroborating the diagnosis of fibrous malignant peritoneal mesothelioma. This case highlights the complexity of neoplastic conditions in hedgehogs and emphasizes the importance of multimodal diagnostic approaches for accurate identification and understanding of these rare diseases.

Copyright © 2024 Troncoso, Brown, Isla, Lajara, Ebner and Fehrmann-Cartes.

In plain English

This veterinary case report describes one pet animal: a 2.5-year-old male African pygmy hedgehog brought to a clinic in Concepción, Chile, in January 2022 with intense abdominal pain. Ultrasound showed a mass 1.22 cm across next to the bladder region and a loop of intestine. A fine-needle sample contained cells meeting criteria for malignancy. About two weeks later the mass was removed by surgery; it had two lobes measuring 2.5 cm and 1.5 cm. Under the microscope it contained mesothelial cells, abundant fibrous tissue and small fluid-filled cysts. The cells stained positive for calretinin and mesothelin and negative for cytokeratin 5/6. The final diagnosis was localized malignant fibrous peritoneal mesothelioma. The hedgehog improved after surgery but died about a month after a check-up held two weeks post-surgery. The authors noted that the staining markers are not validated for hedgehogs. The study did not examine asbestos, and the authors wrote that the cause of mesothelioma in hedgehogs is still unknown. They concluded that fibrous mesothelioma is a plausible diagnosis for abdominal tumors in hedgehogs.

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 (single animal)
• Who was studied: One 2.5-year-old male African pygmy hedgehog (Atelerix albiventris) seen at a veterinary clinic in Concepción, Biobío District, Chile, on 21 January 2022
• Exposure: No asbestos or other exposure was studied. The authors state that the cause of mesothelioma in hedgehogs is unknown. They mention asbestos only when describing humans and dogs, citing other studies.
• Main results:
  • Abdominal ultrasound showed a hypoechoic mass 1.22 cm in diameter next to a jejunal loop of intestine.
  • Fine-needle aspiration cytology showed a few oval-shaped cells meeting criteria for malignancy.
  • At surgery the tumor was in the peritoneal cavity, attached ventral to the bladder.
  • The tumor had two lobes, measuring 2.5 cm and 1.5 cm.
  • Histopathology showed small cysts filled with serous fluid, covered by flattened or cuboidal mesothelial cells.
  • Immunohistochemistry was positive for calretinin and mesothelin and negative for cytokeratin 5/6 (CK5/6).
  • The final diagnosis was localized malignant fibrous peritoneal mesothelioma.
  • The hedgehog improved after surgery. It died 1 month after a check-up held about 2 weeks post-surgery, following 2 days of acute deterioration.
• The authors' conclusion: The authors concluded that fibrous mesothelioma is a plausible diagnosis for abdominal neoplasia in hedgehogs.
• Limitations the authors state:
  • The immunohistochemistry markers used are not validated for hedgehogs.
  • No normal hedgehog tissue was available as a positive control for the markers.
  • On ultrasound the tumor nodules were hard to distinguish because of kidney swelling (hydronephrosis) and fluid in the abdomen, so a second scan was needed.
  • On cytology, reactive (inflamed) cells look very similar to tumor cells.

Topics

Medical terms in this study, explained in our Lexicon: Mesothelioma, Mesenchymal Tumor, Prognosis, Mesothelial Cells, Ultrasound, Serous Fluid, Immunohistochemistry, Calretinin.

Related studies

• Carbon nanotubes introduced into the abdominal cavity of mice show asbestos-like pathogenicity in a pilot study — C.A. Poland, R. Duffin, et al. (2008)
• Asbestosis and abdominal neoplasms — E.E. Keal (1960)
• Multi-institutional experience of diffuse intra-abdominal multicystic peritoneal mesothelioma — T.C. Chua, T.D. Yan, et al. (2011)
• Neoplasia among insulation workers in the United States with special reference to intra-abdominal neoplasia — E.C. Hammond, I.J. Selikoff, et al. (1965)
• Loss of BAP1 expression is very rare in peritoneal and gynecologic serous adenocarcinomas and can be useful in the differential diagnosis with abdominal mesothelioma — J. Andrici, J. Jung, et al. (2016)
• Genome-wide analysis of abdominal and pleural malignant mesothelioma with DNA arrays reveals both common and distinct regions of copy number alteration — A.C. Borczuk, J. Pei, et al. (2016)

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