First Report and 3D Reconstruction of a Presumptive Microscopic Liver Lipoma in a Black Barbel (Barbus balcanicus) from the River Bregalnica in the Republic of North Macedonia

• Published in: Applied sciences 2021-09, Vol.11 (18), p.8392
• Main Authors: Rebok, Katerina, Jordanova, Maja, Azevedo, Júlia, Rocha, Eduardo
• Format: Article
• Language: English
• Subjects: 3D reconstruction; Adipocytes; Barbus balcanicus; Blood vessels; Carbohydrates; Connective tissue; Cytoplasm; Freshwater fish; Lipids; Lipoma; Liver; Marine fish; microlipoma; Organs; Parenchyma; Reconstruction; Tumors; Tuna; Vertebrates
• ISSN: 2076-3417; 2076-3417
• DOI: 10.3390/app11188392

A lipoma is a benign tumour of mature adipocytes which may appear in various species, including marine and freshwater fish. It usually occurs in isolated locations, such as a superficial or deep mass, mainly in the skin and seldom in other organs. In non-mammalian vertebrates, there is no agreed minimal size for the mass to be considered a lipoma. This study histologically describes a case proposed to be a microlipoma in the liver of Barbus balcanicus. The structure was an oval-shaped mass of well-differentiated adipocytes, surrounded by hepatic parenchyma. The adipocyte cluster did not contact with major vascular or biliary tracts, the liver capsule, or the hilum. The cell mass reached a maximal linear length and width of ~0.5 mm and ~0.4 mm. A three-dimensional and software-assisted reconstruction of the adipocytic mass showed that it had the shape of a flattened prolate spheroid (~0.01 mm3). Given the histological criteria currently used in the literature, we consider the mass as a lipoma, or, better, a microlipoma because it was tiny. We interpret this structure as an early growing lipoma. This work is the second description of a liver lipoma in a fish to the best of our knowledge.