Pigmented ameloblastic fibrodentinoma: a novel melanin-pigmented intraosseous odontogenic lesion

Abstract

This paper reports about an ameloblastic fibrodentinoma with macroscopically visible pigmentation, resulting in the clinical appearance of a melanotic lesion in a 21-year-old Japanese male. In addition to the characteristic histopathologic features of ameloblastic fibrodentinoma, various-formed and -sized cells, which were considered to be melanophages containing numerous aggregates of melanin pigment in their cytoplasm, were densely distributed throughout the mesenchymal component. In addition, melanin pigment was deposited in dentin. Some of the pigmented cells showed dendritic form and were regarded as melanocytes. Furthermore, pigmented cells were frequently distributed in the epithelial component, and melanin pigment was seen in some epithelial cells. Perusal of the English language literature revealed 30 cases of pigmented odontogenic tumors: 18 were calcifying odontogenic cysts, three were ameloblastic fibro-odontomas, three were adenomatoid odontogenic tumors, two were odontomas, one was an ameloblastic fibroma and one was an odontogenic fibroma. However, all of these reported lesions did not show macroscopically visible pigmentation. The possible histogenesis of melanocytes in the odontogenic lesions is discussed, although no firm conclusion could be drawn.

Melan-A/Mart-1- or HMB-45-positive melanocytes are not present in calcifying cystic odontogenic tumors (calcifying odontogenic cysts): a study in 13 Caucasian patients

“…These melanocytes could remain latent before being activated to produce melanin (9,11). The findings of the present study do not support the presence of latent melanocytes in CCOT epithelium or mesenchyme, as those cells would be revealed by Melan-A/Mart-1.…”

“…In previous studies, melanocytes in odontogenic lesions have been described as reactive for S-100 protein (1,2,4,7-12), non-reactive for melanomaassociated antigen (7), and reactive (12,13) or non-reactive (9,14) for HMB-45 antigen. In the present study, we applied two antibodies that can identify both active and inactive melanocytes.…”

“…Melanin may be easily overlooked in routine histological sections, as it resembles hemosiderin and its presence should be confirmed by Masson-Fontana silver impregnation (4). Melanocytes may be present even in the absence of melanin (5,6) and can be recognized by electron microscopy (1,(5)(6)(7)(8) and immunohistochemistry for S-100 protein (1,2,4,7-12), melanoma-associated antigen (7), or HMB-45 antigen (9,(12)(13)(14).…”

Pigmented pleomorphic adenoma, a novel melanin-pigmented benign salivary gland tumor

“…The examples of the former are basal cell carcinoma and squamous cell carcinoma [3,8], hair follicle tumors [22], eccrine gland tumors [21], and mammary and extramammary Paget disease [9,12]. Examples of the latter, which are rare, are ovarian adenocarcinoma [20], thymic carcinoma [7,10], prostatic carcinoma [2,6,13], and various types of intraosseous odontogenic tumors [18].…”

Pigmented mucoepidermoid carcinoma, a case report and review of the literature on melanin-pigmented salivary gland tumors

“…Examples of the former are basal cell carcinoma and squamous cell carcinoma (2,3), hair follicle tumors (4), eccrine gland tumors (5), and mammary and extra-mammary Paget disease (6,7). Examples of the latter, which are rare, are ovarian adenocarcinoma (8), thymic carcinoma (9,10), prostatic carcinoma (11)(12)(13), and various types of intra-osseous odontogenic tumors (14).…”