Lymph node hemangioma in one-humped camel.

Hemangioma is a benign tumor of blood and lymphatic vessels. It is common in skin, mucosa and soft tissues, and its occurrence in lymph nodes is extremely rare. A 10 year-old she-camel was slaughtered at Nyala slaughterhouse, South Darfur State, Sudan. Grossly, the carcass was emaciated. The left ventral superficial cervical lymph node was enlarged, hard on palpation and protruded outside the body. Its cut surface was dark red in color and measured (18 cm) in diameter. Histopathologically, the sections revealed vascular masses were composed of non-encapsulated clusters of small and medium sized with thick and thin-walled, filled with blood, separated by courageous stroma and surrounded by closely packed proliferating capillaries. To the best of our knowledge, this is the first record of the left ventral superficial cervical lymph node hemangioma in a camel in the Sudan.

Introduction

Hemangiomas are benign tumors of the blood and lymphatic vessels. In animals, hemangiomas are common in dogs but rare in cats, horses and other domestic animals (Goldschmidt and Hendrick, 2002). Although canine hemagiomas are commonly located in the skin (Hargis et al., 1992; Schultheiss, 2004), they are also recorded in the spinal cord, tongue, liver, kidneys, spleen, conjunctiva and synovial joints (Cordy, 1979; Schoofs, 1997; Rallis et al., 1998; Eddlestone et al., 1999; Schultheiss, 2004; Pirie et al., 2006; Miller et al., 2007). Feline hemangiomas have been reported in the tongue, skin and conjunctiva (Crow et al., 1981; Miller et al., 1992; Pirie and Dubielzig, 2006). In the horse, cutaneous hemangiomas are the commonest (Johnson et al., 1996).

Although hemangioma is common in skin, mucosa and soft tissues, its occurrence in lymph nodes is extremely rare (Reich et al., 2000). Hemangioma has been recorded from abattoir derived liver specimens in camel (El-mahdy et al., 2013).

Grossly, in the lymph node hemangioma the size of the involved lymph nodes ranges from 2 to 35 cm (Chan et al., 1992; Dellacho et al., 1999). Microscopically, hemangiomas are characterized by proliferating, vasoformative mesenchymal tissue forming capillary and cavernous vessels and less often, arterial and venous structures. Endothelial cells in these tumors may be surrounded by pericytes and fibroblasts (Calonje and Fletcher, 2007).

Hemangiomas may be classified as capillary or cavernous, lobular capillary, cellular and epithelioid (Chan et al., 1992; Tsang et al., 1994; Reich et al., 2000). The capillary or cavernous hemangioma is more often centered on the lymph node hilum or medulla with well-preserved nodal parenchyma (Tsang et al., 1994; Ioachim and Medeiros, 2008) and is either a well-defined or poorly defined mass of closely packed capillaries or cavernous vessels lined by flat endothelial cells which can be empty or filled with blood (Dellacho et al., 1999; Reich et al., 2000). The lobular capillary type can almost replace the entire nodal parenchyma and has an appearance similar to a pyogenic granuloma (Chan et al., 1992). The cellular type is composed of closely packed, nearly solid or rarely canalized, vascular channels that can be outlined by periodic acid-Schiff and reticulin stain (Chan et al., 1992). The epithelioid type is characterized by plump endothelial cells (Chan et al., 1992; Dellacho et al., 1999). This report describes the gross and histopathological features of hemangioma present in the left ventral superficial cervical lymph node of a camel slaughtered at Nyala slaughterhouse in South Darfur State in Sudan.

Case Details

A 10 year-old she-camel (Camelus dromedarius) was brought from West Darfur State and slaughtered at Nyala slaughterhouse for human consumption. Grossly, the carcass was emaciated. However, further examination did not reveal any detectable abnormalities. The size of the left ventral superficial cervical lymph node was enlarged, hard on palpation and protruded outside of the body surface (Fig. 1A). It was mounted 18 cm in diameter and dark red in color (Fig. 1B).

Fig. 1

Gross appearance of the left ventral superficial cervical lymph node showing enlargement, hard on palpation and protruded outside the body (a), dark red in color and measured (18 cm) in diameter (b).

The lymph node was excised from the body and fixed in 10% neutral buffered formalin and submitted to the Department of Pathology in Veterinary Research Institute (VRI) in Khartoum for microscopic evaluation. The specimen was processed by routine methods, embedded in paraffin wax, sectioned at 5μm thickness and stained with hematoxylin and eosin (H&E) for histopathological examination (Bancroft et al., 1994).

Histopathological findings revealed vascular masses, were composed of non-encapsulated clusters of small and medium sized with thick and thin-walled, filled with blood, separated by courageous stroma and surrounded by closely packed proliferating capillaries (Fig. 2). This finding is consistent with diagnosis of hemangioma (Dellacho et al., 1999).

Fig. 2

Histopathological sections of the left ventral superficial cervical hemangioma showing vascular masses were composed of non-encapsulated clusters of small and medium sized with thick and thin-walled, filled with blood, separated by courageous stroma and surrounded by closely packed proliferating capillaries (H&E x 40).

Discussion

Although hemangioma is common in the skin, mucosa and soft tissues, its occurrence in lymph nodes is extremely rare (Reich et al., 2000). The gross and histopathologic features of the findings reported in the left ventral superficial cervical lymph node is consistent with the report of Dellacho et al. (1999) who described that grossly in the lymph node hemangioma, the size of the involved lymph nodes were ranged from 2 to 35 cm in diameter. Moreover, vascular masses, composed of non-encapsulated clusters of small and medium sized with thick and thin-walled, filled with blood, separated by courageous stroma and surrounded by closely packed proliferating capillaries were characteristic in this report. Previous reports have mentioned that capillary or cavernous hemangioma is more often centered on the lymph node hilum or medulla with well-preserved nodal parenchyma (Tsang et al., 1994; Ioachim and Medeiros, 2008) and is either a well-defined or poorly defined mass of closely packed capillaries or cavernous vessels lined by flat endothelial cells which can be empty or filled with blood (Dellacho et al., 1999; Reich et al., 2000). To the best of our knowledge, this is the first record of the left ventral superficial cervical lymph node hemangioma in a camel in the Sudan.