Infantile hemangioma in a subadult Chinese pangolin: a case report

Abstract

Background: Hemangiomas are a relatively common type of tumor in humans and animals. Various subtypes of hemangiomas have been described in the literature. The classification methods for hemangiomas differ between human and veterinary medicine, and the basis for tumor classification can be found in the literature.

Case presentation: This study describes a tumor in the subcutaneous tissue of the right dorsum of an artificially rescued juvenile Chinese pangolin. Computed tomography (CT) examination yielded the preliminary diagnosis of a vascular malformation, and surgery was performed to resect the tumor. Histopathological examination showed that the tumor mainly was consisted of adipose tissue, capillaries, and spindle cells in the fibrous stroma. Immunohistochemistry showed the positive expression of CD31, CD34, α-SMA, GLUT1 and WT-1 in the tumor tissue, and the tumor was eventually diagnosed as an infantile haemangioma.

Conclusion: The final diagnosis of infantile hemangioma was depended on the histopathological immunohistochemical and CT examination of the neoplastic tissue. This is the first report of infantile hemangioma in a critically endangered species Chinese pangolin.

Keywords: CT; Chinese pangolin; Histopathology; Immunohistochemistry; Infantile hemangioma.

Fig. 1

Imaging characteristics of the hemangioma in the Chinese pangolin. a. CT angiography 3D reconstruction; the blue arrow indicates the hemangioma, and the gray arrow indicates the blood supply vessel. b. 2D CT; the gray arrow indicates the blood supply vessel

Fig. 2

Histopathological staining results of the tumor. The mass was composed of multiple nodules with well-defined borders and no membranes (Fig. a, 1×), and the mass was nondestructively mixed with adipose tissue (Fig. b, 10×). Some regions of the mass were composed of numerous capillaries filled with many red blood cells (Fig. c, 40×). The capillaries were lined with endothelial cells with round to oval nuclei, and the interstitial components were not clear. Collagen fibers were dissolved, and there was interstitial edema (Fig. d, 40×). The interstitium was significantly widened, and many filamentous collagen fibers, as well as proliferated capillaries, were observed, along with many neutrophils in some local areas (Fig. e, 40×). The proliferative capillaries exhibited good differentiation, with little cellular atypia and few mitotic figures. In some areas, the tumor was composed solely of spindle-shaped cells in the fibrous stroma, and groups of these spindle-shaped cells were mixed with microtubular structures (Fig. f, 40×)

Fig. 3

ab. Strong expression of CD31 and α-SMA in the cytoplasm of proliferating vascular endothelial cells (black arrows). c. CD34 expression only in capillary endothelial cells (black arrows). d. NO CD34 expression in the vascular lumen composed of spindle cells (black arrows). e. Weak GLUT-1 expression (black arrows). f. Weak WT-1 expression (black arrows)