Histopathologic studies of benign infantile hemangioendothelioma of the parotid gland

Abstract

Five hundred and eighty-four cases of primary parotid gland tumors and tumor-like conditions were examined. Primary benign hemangiomas of the parotid gland were relatively rare, comprising 29 cases (4.9%) of 584 tumors. These could be divided into either cavernous hemangioma or so-called benign hemangioendothelioma. In our series, the incidence of the latter was 1.5% (nine cases), or 31.0% of the total number of hemangiomas. The so-called benign hemangioendotheliomas were found in patients under the age of 12 months, during the infantile period, and occurred predominantly in females and on the right side. Histologically, this tumor showed a uniform growth pattern so that each lobular portion exhibited a strikingly identical appearance. The vascular lumina of the tumor were lined by flattened endothelial cells that were occasionally mixed with some plump cells showing mild atypism. Electron microscopy revealed that the tumor consisted of two distinct components, one being definite endothelial cells lining the vascular channels and the other pericytes located outside of the endothelium embracing the vascular channels. The tumor cells can be interchangeable with one another. It seems that this tumor is derived from the intralobular vascular system of the parotid gland. This tumor is benign in nature and found almost exclusively during the infantile period. Hence, from the clinicopathologic aspect, "benign infantile hemangioendothelioma" seems to be a more suitably descriptive term than simply "benign hemangioendothelioma".

Endobronchial juvenile hemangioma - a case report of a neonate including immunohistochemical monitoring and nuclear, cellular, and vascular morphometry

“…In neonates, no such tumor originating from the air conduction system has up to now been described to our knowledge. However, infantile hemangiomas are known to occur infrequently in liver, the periparotid region, skin, or all compartments of the mediastinum [2,3,8,9,20].…”

Cavernous Hemangioma of the Parotid Gland

“…Cavernous hemangioma usually presents in late childhood or early adulthood and is unlikely to regress spontaneously or with conservative measures; 10,26 hence, the treatment of choice is surgical excision. This is also indicated because of the difficulty in distinguishing the lump from other parotid tumors.…”

“…16 There is no sex or side predilection. 10,17 Extralobular rather than intralobular connective tissue of the gland is involved. 17 The pulsatile flow in end arteries over a long period may cause the change of capillary hemangioma into a cavernous one.…”

“…17 The pulsatile flow in end arteries over a long period may cause the change of capillary hemangioma into a cavernous one. 10 Parotid cavernous hemangioma may present as a solitary lump in the parotid region 26,28,29 or as a diffuse swelling. 11,31 It is usually soft but could be firm or spongelike.…”

“…It accounts for 1% to 5% of all salivary gland tumors, and over 90% are found in the parotid gland. [7][8][9] There is a controversy over whether or not hemangioma is a true benign tumor of blood vessels 10 or a vascular malformation, i.e., a hamartoma. [11][12][13] Caldwell and Campbell [14][15] reported the first parotid hemangioma in the British literature while Faber et al 12 reported the third series of adult parotid hemangioma in the British literature in 1978 after Gascoyen, 16 Dempsey and Murley.…”