Primary malignant melanoma of the oral cavity. A review of 177 cases

Abstract

Malignant melanoma of the oral cavity is rare, accounting for about 1% to 8% of all melanomas. There have been no prospective studies of melanoma in this location, and all previous papers have reported small numbers of cases or have retrospectively reviewed case reports from the literature. The authors report six new cases and review 171 cases published since the last major review in 1975. The classification of oral melanomas with radial growth phases is discussed.

Mucosal malignant melanomas in head and neck surgery: a retrospective study of six patients and review of the literature

“…Another important prognostic factor is the early metastasis in oral malignant melanomas because, in certain localizations like the palate, the tumor does not need to invade very deeply before reaching the bone, and radiologic evidence of bony erosions has been associated with early hematogeneous spread [2]. In our study population, all patients had malignant melanomas in the upper jaw.…”

“…Melanoma of the mucosa is very rare, presenting in only 1.3% of all melanomas [1], and it is especially rare in patients below the age of 30 years [2]. The peak age is between 65 and 79 years [3].…”

“…For mucosal melanomas, distribution on the head and neck occurs in 55.4% of cases, followed by anal/rectal (23.8%), female genital tract (18%), and urinary tract sites (2.8%) [1]. The most frequently affected sites in the oral cavity are the maxillary gingival and the palate [5,6], and they are more commonly affected in Japan and Africa than in Western countries [2,7,8]. The development of oral malignant melanomas (OMM) and the function of melanocytes in the oral mucosa have still not been clearly identified.…”

“…It is striking, however, that in the squamous mucosa, men are affected 3.5 times more frequently than women. [9] Three criteria for the diagnosis of primary oral melanoma were proposed by Greene et al [10]: (1) demonstration of malignant melanoma in the oral mucosa, (2) presence of "junctional activity" in the lesion, (3) and inability to show malignant melanoma at another primary site. But junctional activity is now seen as an unreliable indicator that the lesion is primary, because melanoma metastasis can also involve the epithelium junction.…”

“…Furthermore, two different growth patterns have been mentioned: (1) a radial growth phase that tends not to invade the underlying reticular corion, but is associated with metastasis and (2) the vertical growth pattern, invasive and growing before metastasis can occur [3]. For mucosal malignant melanomas, Clark`s level of invasion cannot be applied because of missing histological landmarks like papillary and reticular dermis [11]; in addition, oral malignant mucosas have a radial growth phase [2] with early metastasis.…”