Relative frequency of solitary melanocytic lesions of the oral mucosa.

BACKGROUND: Solitary pigmented lesions of melanocytic origin are uncommon in the oral mucosa. These lesions include the oral and labial melanotic macule, oral melanocytic nevus, oral melanoacanthoma, oral melanoma and atypical melanocytic proliferation. The purpose of the study was twofold: to report a large series of solitary melanocytic lesions from one source, and to determine the relative frequency of these lesions. METHODS: The study was based on a systematic search of the files of the Pacific Oral and Maxillofacial Pathology Laboratory, University of the Pacific, San Francisco for solitary pigmented melanocytic lesions (benign and malignant) accessed during the years 1984-2002. RESULTS: Of the 89 430 biopsies accessed during the 19-year period, 773 (0.83%) cases of solitary pigmented melanocytic lesions in the oral mucosa were identified. Oral and labial melanotic macules were the most common melanocytic lesions comprising 86.1% of the entire group and 0.7% of the total number of accessed biopsies. The vermilion border and gingiva were the most common sites (31.1% and 31.0% respectively). Oral melanocytic nevi comprised 11.8% of the entire melanocytic group and 0.1% of the total number of biopsies. The most common site was the palate (44%). Intramucosal nevi were the most common (64%), followed by compound nevi (16.5%) and common blue nevi (16.5%). Junctional nevi were uncommon (3.0%). Oral melanoacanthoma comprised only 0.9% of the entire melanocytic group and 0.008% of the total number of biopsies. Oral melanoma and atypical melanocytic proliferation were the least common lesions each comprising 0.6% of the entire melanocytic group and 0.006% of the total number of biopsies. The most common site for oral melanoma was the palate (60%). CONCLUSION: The palate was the most common location for both melanocytic nevi and oral melanoma. Thus, all melanocytic lesions in the palate should be viewed with caution and biopsy is recommended to rule out melanoma. Further studies are required to elucidate the entity of oral atypical melanocytic proliferation.

Peripheral (extraosseous) calcifying odontogenic cyst. A review of forty-five cases.

The peripheral calcifying odontogenic cyst (PCOC) is a rare lesion. The number of well-documented cases reported in the English-language literature until now is 38. The purpose of the present study is twofold: (1) to report seven new cases of PCOC and (2) to review and analyze the clinical and histomorphologic features of the previously reported cases of PCOC together with those of the present study. Most of the lesions were located in the maxillary and mandibular gingiva or alveolar mucosa anterior to the region of the first molar. Histologically, 66% of the lesions were of the cystic variant and 34% of the solid (neoplastic) variant. The terminology of the lesion and its histogenesis are discussed.

Adenomatoid hyperplasia of minor salivary glands.

Adenomatoid hyperplasia of minor salivary glands is an uncommon clinicopathologic entity. It comprises clinical swelling resembling a neoplasm with a histologic picture of aggregates of normal-appearing salivary gland tissue in excess of that anticipated for the anatomic site. The significance of this lesion is derived from its clinical resemblance to a neoplasm of salivary gland origin. This study adds 40 new cases to the literature and analyzes their clinical and histologic features. Most of the lesions were located on the hard and soft palates. The exact nature of the minor salivary gland hyperplasia is not clear. Some of the cases may represent a hamartoma or a reactive hyperplasia, but in most cases the nature of the hyperplasia is idiopathic.

Anterior lingual mandibular salivary gland defect. Evaluation of twenty-four cases.

Lingual mandibular salivary gland defects in the posterior part of the mandible are not uncommon. Analogous defects in the anterior region, however, are rare, and the four new cases presented in this report bring the total number of reported cases up to 24. The purpose of the present study was to review and analyze the clinical, radiographic, and histologic features of the previously reported cases together with those of the present study. The majority of these defects were located in the cuspid and/or premolar area and were diagnosed in men in their fifth and sixth decades of life. Almost all defects contained normal salivary gland tissue. The differential diagnosis, treatment, and pathogenesis of these defects are discussed.

Melanocytic hyperplasia of the oral mucosa.

Lesions that exhibit melanocytic hyperplasia are uncommon in the oral mucosa. They are even more rare than the various morphologic types of nevomelanocytic lesions. This article reports the clinicopathologic features of oral lesions diagnosed as lentigo simplex, junctional lentigo ("jentigo"), atypical melanocytic hyperplasia (melanoma in situ), and melanocanthoma. The proper terminology for these lesions is also discussed.

Oral focal mucinosis.

Oral focal mucinosis (OFM) is an uncommon clinicopathological entity which is considered to be the oral counterpart of cutaneous focal mucinosis and/or cutaneous myxoid cyst. It is comprised of a clinically elevated mass with a histological picture of localized areas of myxomatous connective tissue. The present study adds 15 new cases of OFM to the literature and analyzes their clinical, histological and histochemical features. Most of the lesions were located in the gingiva and alveolar mucosa. The nature of the lesion is unclear and it is suggested that the mucinous accumulation is the result of fibroblastic overproduction of hyaluronic acid.

Central (intraosseous) calcifying odontogenic cyst.

The central calcifying odontogenic cyst (CCOC) is an uncommon lesion. The present study reports 17 new cases of CCOC and analyses their clinical and histomorphologic features. The data revealed that CCOC were usually diagnosed in the second decade of life with an almost equal distribution between the maxilla and the mandible. Six of the 17 cases (35%) were associated with odontomas and 6 lesions (35%) were associated with unerupted teeth. Histologically, most of the lesions were unilocular cysts but at least one was multilocular and one was a mixed lesion - partially cystic and partially solid. Excision with long-term follow-up (up to 10 years) is the treatment of choice.

Oral intravascular papillary endothelial hyperplasia.

Intravascular papillary endothelial hyperplasia (IPEH) is usually a cutaneous lesion thought to represent a peculiar manifestation of an organizing thrombus. IPEH can be subdivided into a pure form that occurs within a dilated vascular space and a mixed form that appears as a focal change within a preexisting vascular lesion, such as hemangioma. The principle significance of the lesion lies in the fact that it may be mistaken for angiosarcoma. Oral lesions are uncommon and the present paper reports on 16 new cases of oral IPEH, analyzing their clinical and histomorphologic features. Histologically, 11 lesions appeared in a pure form and 5 lesions in a mixed form. Thrombi were detected in all but one case. The most common location was the lip, followed in decreasing frequency by the tongue and buccal mucosa. Local excision was the treatment of choice.

The retrocuspid papilla of the mandibular lingual gingiva.

The retrocuspid papilla (RCP) is a circumscribed nodule that lies lingual to the mandibular cuspid on the gingival tissue. RCP is observed more frequently in young children and seems to regress or disappear with age. Little information is available in the literature on this entity and there are contradictory reports regarding its histologic features. Histomorphologic analysis of 30 specimens diagnosed as RCP revealed that in most cases (80%) it is composed of loosely-arranged delicate fibrous connective tissue with stellate and multinucleated fibroblasts. Elongation of the rete ridges and/or increased vascularity are also present in a significant number of cases. Stellate and multinucleated fibroblasts are not unique to RCP and they have been described as prominent histologic features in other lesions of skin and mucous membrane. RCP is considered to be a "normal anatomical structure" or an "anatomic variation" of the gingiva. The clinical significance of RCP is that it may simulate pathological gingival conditions from which it must be differentiated.

Melanocytic nevi of the oral mucosa: a clinicopathologic study of 130 cases from northern California.

This paper presents analysis of data on 130 cases of oral melanocytic nevi from the files of the University of the Pacific, San Francisco and the University of California, San Francisco. This is the largest detailed series from one geographic location published to date. Nevi of the intramucosal type are the most common (63%) followed by the common blue nevus (19%). Compound nevi are uncommon (9%) and junctional nevi are rare (5%). Combined nevi are the rarest type (4%). The data are analyzed as to the location, presence of clinical pigmentation, configuration, and size of the nevi, as well as the patient's age, gender and race. Because the malignant potential of oral nevi is still uncertain and because preexisting macular pigmentation is present in about one third of all patients with oral melanoma, it is advisable to remove all pigmented lesions suspected to be melanocytic nevi.

Intraoral solitary glomus tumor (glomangioma): case report and literature review.

The glomus tumor, or glomangioma, is a benign neoplasm arising from the normal glomus. Glomus tumors of the oral cavity are rare, with only ten cases reported in the literature. We report the light and electron microscopic features of an additional case of glomus tumor of the lip which occurred as a solitary, painless, submucosal mass in a 51-year-old woman. Clinical, diagnostic, and histogenetic aspects are discussed.

Radiographic characteristics of central ossifying fibroma.

Sixty-four instances of histologically documented ossifying and/or cementifying fibromas were evaluated. Adequate radiographs were available in 43 of the cases. Most of these benign fibro-osseous neoplasms occurred in women, with a predilection for the third and fourth decades. Six distinct radiographic patterns could be identified: (1) radiolucent, superimposed over teeth or residing in edentulous regions (28%); (2) radiolucent with opaque foci, lying in edentulous areas or superimposed over teeth (42%); (3) radiolucent, interposed between contiguous teeth (5%); (4) radiolucent with opaque foci, interposed between contiguous teeth (9%); (5) multilocular expansile (7%); and (6) aggressively expansile with opacification (9%). All lesions exhibited well-defined margins. Root resorption was a feature in 11% of the sample, and root divergence occurred in 17% of the cases.

Verruciform xanthoma of the oral mucosa. Report of five cases and review of the literature.

Verruciform xanthoma is an uncommon lesion confined mainly to the oral mucosa. Only two extraoral cases have been reported, and these involved the genitalia. Clinically, verruciform xanthoma is a raised lesion with a papillary or granular surface, usually located on the gingiva or alveolar mucosa. Microscopically, it is characterized by epithelial cell proliferation and by the accumulation of xanthoma cells in the upper lamina propria. Five new cases are reported and analyzed together with an additional 29 cases found in a review of the literature.