Hamartoma of the Oral Cavity with Ectopic Meningothelial Elements in Infants: A Rare Entity with Report of Two Cases

Abstract

Choristomas and hamartomas within the oral cavity are relatively uncommon lesions and may present with diverse clinical and histopathological appearances. In this report, we describe two infant patients with hamartoma with ectopic meningothelial elements involving tongue and maxillary alveolar ridge. To the best of our knowledge, these are the first two cases in which a meningothelial proliferation has been identified in the oral cavity. Hamartoma with ectopic meningothelial elements is a rare condition that has been classically described occurring in the scalp. These lesions are characterized by bland round to spindle-shape cells that interdigitate through collagen bundles and express progesterone receptor and epithelial membrane antigen by immunohistochemistry supporting a meningothelial origin.

Presence of Two Separate Hairy Polyps with Meningothelial Elements in a 15-Month-Old Child

“…Meningothelial cells are the building blocks of the meninges, the protective layers covering the central nervous system [ 18 ]. It is rare for meningothelial cells to be found within another benign tumor in the head and neck [ 19 ]. When found extracranially, meningothelial proliferations can be classified into four categories: extracranial extensions of an intracranial meningioma, extracranial meningiomas, metastatic meningiomas, and primary cutaneous meningiomas [ 7 ].…”

Ectopic meningothelial hamartoma with spindled melanocytes, an unusual finding in a rare neoplasm

“…By immunohistochemistry, cells within these lesions express positivity for vimentin, EMA, and progesterone receptor 9,10 …”

“…8 In terms of anatomic location, most are present within the scalp, although some hamartomas with ectopic meningothelial elements have been reported in the oral cavity on the tongue or at the maxillary alveolar ridge. 9 Histopathologically, EMHs are characterized by nests of polygonal, round, or spindle-like cells with thin-walled anastomosing pseudovascular spaces. Psammomatous calcifications can be seen as well.…”

“…The appearance may be skin‐colored, red, or tan‐gray, and although congenital, they are usually noticed in early childhood or adulthood 8 . In terms of anatomic location, most are present within the scalp, although some hamartomas with ectopic meningothelial elements have been reported in the oral cavity on the tongue or at the maxillary alveolar ridge 9 …”

Development of a calcified odontogenic hamartoma following avulsion of a permanent central incisor

“…Hamartomas are a growth or mass of disordered normal tissues that are rare in the oral cavity and may present with diverse clinical and histopathological appearances. Most of these lesions are located in the tongue and present in individuals less than two years old . Since no similar cases of hamartomatous proliferation as a sequel after tooth avulsion were found in the dental literature, the aim of this case report was to describe the clinical management of an unusual case of an hamartomatous proliferation of odontogenic tissues with calcification that developed after the avulsion of an immature permanent central incisor in an eight‐year‐old female patient.…”