Head and neck mucosal melanoma (MM) is an aggressive and rare neoplasm of melanocytic origin. To date, few retrospective series and case reports have been reported on MM. This article reviews the current evidence on head and neck MM and the molecular pathways that mediate the pathogenesis of this disease. Head and neck MM accounts for 0.7%-3.8% of all melanomas and involve (in decreasing order of frequency) the sinonasal cavity, oral cavity, pharynx, larynx, and upper esophagus. Although many studies have examined MM of the head and neck and the underlying molecular pathways, individual genetic and molecular alterations were less investigated. Further studies are needed to complement existing data and to increase our understanding of melanocytes tumorigenesis.

Oral mucosal melanoma is rare and reported to be more aggressive than its cutaneous counterpart. Due to the rarity of this entity, data on epidemiology, tumor behavior, treatment, follow-up, and survival of patients are mainly based on single case reports. The few existing series of patients show that oral mucosa melanoma has its peak between 41 and 60 years of age, and male to female ratio is 2:1. Preferred oral sites include hard palate and maxillary alveolar crests. Risk factors have not been clearly identified, and surgical treatment is still the treatment of choice for oral mucosal melanomas. The authors retrospectively studied 35 patients with primary melanoma of the oral cavity to report their clinical and pathological features, such as age, sex, site of the tumor, metastasis, treatment, response to therapy, and outcome. We found no significant sex predominance, and the mean age of the patients was 60.6 years, with a range from 9 to 91 years. The majority of the patients (71.42%) had palate commitment, and invasive histopathological aspect was observed in 80% of the specimens (grade 3). Long-distance metastasis was found in 60% of the cases. Fourteen patients were submitted to wide surgical resections, with local relapse being observed in 11 of them (78.5%). The authors suggest that improved outcome in oral malignant melanoma requires the development of new therapies and the prevention of distant metastasis.

Inflammatory bowel disease (IBD) comprises two chronic, tissue-destructive, clinical entities: Crohn's disease (CD) and ulcerative colitis (UC), both immunologically based. Bowel symptoms are predominant, but extra-intestinal complications may occur, including involvement of the oral cavity. Oral involvement during IBD includes several types of lesions: the most common are aphthae; uncommon lesions include, among others, pyostomatitis vegetans and granulomatous lesions of CD. Starting with a presentation of six patients with oral manifestations, which were crucial for the final diagnosis of IBD, a review on the subject is presented. Oral involvement in IBD may be previous or simultaneous to the gastrointestinal symptoms. However, in the majority of cases, bowel disease precedes the onset of oral lesions by months or years. In many patients, the intestinal symptoms may be minimal and can go undetected; thus, most authors believe that the bowel must be thoroughly examined in all patients with suspected IBD even in the absence of specific symptoms. Usually, the clinical course of oral lesions is parallel to the activity of IBD; therefore, oral manifestations are a good cutaneous marker of IBD.

Introduction Ameloblastomas are neoplasms that have inspired great controversy and clinical interest; their incidence, radiographic features, treatment and behavior are still discussed quite often in the literature. In 2017, the classification of these lesions underwent modifications in terminology with the introduction of prospective views based on updates in current genetic studies. Objective To describe the most important features of the new classification, as well as to evaluate the prevalence and the clinical and radiographic characteristics of 136 ameloblastomas. Methodology The clinical-pathological characteristics of 136 patients diagnosed with ameloblastoma in two large hospitals in São Paulo were analyzed. All the hematoxylin-eosin (HE) stained slides were reviewed using an optical microscope (Olympus Cover) and tumors were classified according to the new WHO criteria (2017). Two independent evaluators analyzed the slides; in cases where there was disagreement a third evaluator was used and the result was established in consensus. Results 71% of the lesions were of the conventional type, the predominant histopathological pattern being plexiform (40%), 72% of the tumors showed cortical expansion, and 84% had a radiographic pattern of the multilocular type. The treatment of choice in most cases was segmental resection (45%) and recurrence was present in 13% of the cases. Conclusion Studies with clinical-pathological correlations will be necessary in the near future, in order to provide new therapies that are more effective and conservative, improving the quality of life of patients effected.

Lupus erythematosus (LE) frequently compromises the skin, lips and oral mucosa. There is a large body of medical and dental literature about the cutaneous and mucosal lesions of LE, but very little has been written specifically about labial lupus. The lip has a peculiar anatomical and histological architecture, and LE lesions at this site may have some distinct features. This article reviews the existing data and adds some new concepts to the issue of labial lupus in all of its presentations, comparing such lesions to the well-established characterization of cutaneous LE (in acute, subacute and chronic lesions), and highlighting some special clinical features that may enable a better diagnosis and differential diagnosis of lip diseases.

Alterations in salivary glands of LE patients may be a specific manifestation of the disease (lupus sialadenitis), reflecting its multisystemic presentation, instead of an association of secondary SS and LE.

Xeroderma pigmentosum (XP) is a rare autosomal recessive disorder characterized by clinical and cellular sensitivity, pigmentary changes, and early development of malignancies in sun-exposed mucocutaneous and ocular structures due to a defective ability to repair intracellular DNA damage. Individuals with XP also have a greater frequency of oral cancer, particularly squamous cell carcinoma of the anterior third of the tongue. The current study reports four cases of XP that exhibited a characteristic crescent-shaped, atrophic, telangiectatic area on the distal border of the tongue and correlates this lesion with the development of tumors at this site during follow-up. The tongue lesion was photographed and biopsied in the four patients. During routine follow-up visits, new biopsies were performed if additional tongue lesions were observed. The studied lesions were similar in the four patients. During follow-up, squamous cell carcinoma developed in one patient and pyogenic granuloma developed in three patients and was relapsing in one. The lesion remained stable in one patient during the study. The atrophic and telangiectatic patches probably occur because of chronic sun damage to the exposed portion of the tongue, and this area has a high predisposition for the development of benign and malignant tumors.

Oral mucosal melanoma is rare. Its incidence peaks between 41 and 60 years of age; male/female ratio is 2:1. Preferred oral sites include hard palate and maxillary gingiva. Risk factors have not been clearly identified, but pigmented lesions may be present before the diagnosis of oral melanoma. We report an unusual case of oral mucosal melanoma of long-standing duration on hard palate and maxillary alveolar ridge in a male patient. Histopathologic features confirmed the diagnosis of invasive melanoma with a prominent in situ component. A cell lineage derived from the tumor was established and characterized, with phenotypic markers of melanocytes.