Karina Helen Martins

Background: Lichenoid and granulomatous stomatitis (LGS) is a rare condition, with clinicopathological features resembling lichenoid and granulomatous dermatitis. Despite increasing reports, its etiology remains unclear and detailed immunohistochemical (IHC) studies are lacking. Methods: We analyzed three new LGS cases, comparatively assessed with six cases each of oral lichen planus (OLP), oral lichenoid lesion (OLL), and oral leukoplakia (OL) showing lichenoid infiltrate. Histopathologic patterns were classified using the modified Magro & Crowson system, and IHC analysis included lymphocyte subsets, macrophages, and dendritic cells. Statistical comparisons were performed using Kruskal–Wallis with Dunn's post hoc test. Results: All LGS cases showed lymphohistiocytic infiltrates, microgranulomas, and perivascular/perineural lymphohistiocytic aggregates. IHC analysis revealed that LGS showed a significantly larger amount of macrophages (CD11c+/CD68+/CD163+) indicating M1/M2 equilibrium, CD3+ and CD8+ T‐cells, FOXP3+ regulatory T‐cells, and submucosal dendritic cells (FXIIIA+/CD209+) when compared to OLP/OLL/OL. Langerhans cells (CD1a+/CD207+) were similarly observed, whereas CD20+ B‐cells were scarce. Conclusions: This study provides the first comprehensive IHC analysis of LGS, highlighting distinctive macrophage, T‐cell, and dendritic cell profiles. These findings contribute to understanding LGS pathogenesis, support its diagnostic distinction, and suggest potential immunotherapeutic targets.

Lymphomatoid papulosis (LyP) type E is a rare form of primary cutaneous CD30 ⁺ lymphoproliferative disorder characterized by recurrent ulcerative lesions on the skin and/or mucous membranes, after a course of remissions and relapses; however, it is a localized disease with a good prognosis. We have previously reported 2 cases of LyP types C and D with exclusively intraoral involvement. To date, 32 cases of intraoral LyP have been reported. Of them, only 3 cases were diagnosed as LyP type E. We report a 17-year-old Mexican female patient who developed multiple intraoral lesions, without skin or other mucosal surface involvement, with episodes of remission and exacerbation. Histopathologic analysis revealed infiltrates of small-to-medium-sized atypical lymphoid cells, with foci of angiocentric and angioinvasive pattern. By immunohistochemistry, the atypical lymphoid cells were positive for CD3, CD5, CD7 (partial loss), and CD8. Unlike TCRD, TCRBF1 highlighted numerous atypical lymphoid cells, which were also CD30, granzyme B, perforin, TIA-1, and MUM1 positive, and whose angiocentric and angioinvasive pattern was evidenced through CD34 and α-SMA markers. EBER1/2 was negative, with Ki-67 highlighting most atypical lymphoid cells. Treatment with topical corticosteroids has provided considerable improvements, showing resolution of lesions. To the best of our knowledge, this is the first case of LyP type E affecting a pediatric patient with lesions confined to the oral mucosa.

Heck’s disease, or focal epithelial hyperplasia, is a rare benign oral condition classically associated with human papillomavirus (HPV) types 13 and 32, mainly affecting children and adolescents in specific ethnic groups, particularly indigenous populations. Although cases have been reported in the Brazilian Amazon region, published reports from other Brazilian regions, especially urban centers in the Southeast, remain scarce. We report the case of an 11-year-old Venezuelan refugee boy from the Warao indigenous community who was evaluated at a pediatric dentistry service in the state of São Paulo, Brazil, presenting multiple intraoral papules and nodules. The diagnosis was established by clinicopathologic correlation and was consistent with Heck’s disease. This case highlights the importance of recognizing Heck’s disease in non-endemic urban settings and of including oral mucosal assessment in the care of vulnerable pediatric populations, particularly migrant and refugee children.

Sclerotic fibroma (SF), initially described as a cutaneous manifestation of Cowden syndrome (CS), is an uncommon, well‐circumscribed tumor characterized by sclerotic, hyalinized collagen bundles. Originally considered a sclerotic variant of benign fibrous histiocytoma (BFH), most SFs express FXIIIA, and despite this, there is limited investigation of other histiocytic markers. Additionally, SF‐like changes in BFH and other cutaneous lesions may create diagnostic pitfalls. Nonetheless, consistent expression of CD34 and CD99, in close histomorphological correlation, supports the diagnosis of SF. To date, approximately 11 intraoral SFs have been reported, none associated with CS. We present an immunohistochemical analysis of a typical SF in the buccal mucosa of a 46‐year‐old male without signs of CS. Immunohistochemistry showed positivity for vimentin, CD34, CD99, collagen IV (focal), and α‐SMA (focal). Notably, CD68, CD163, FXIIIA, and lysozyme were also positive, suggesting a histiocytic population infiltrating the stroma. This case reinforces that histomorphology, along with CD34 and CD99 immunoprofile, is essential to distinguish SF from BFH and other sclerosing mesenchymal neoplasms. Furthermore, our findings raise the possibility that a subset of SFs may harbor a histiocytic component, which could contribute to its pathogenesis or reflect a reactive stromal component.

Adenomatoid odontogenic tumor (AOT) is a distinct benign odontogenic tumor, with relevant studies indicating that a cystic component can be found in about half of cases; however, controversy still exists regarding its true nature. Here, we show an interesting case of follicular AOT affecting the maxilla of a 13-year-old girl, which was predominantly cystic with intraepithelial calcified deposits, including histomorphological changes of its basal and parabasal layers, in close connection with typical AOT nests, the same ones that looked like detach or originate from this cystic component. Our findings suggest the that the cystic component is part of the tumor in an AOT subgroup, which should also be considered.

Introduction Mesenchymal chondrosarcoma (MC) is a rare neoplasm representing about 3% of all chondrosarcomas and 0.1% of all head and neck cancers. To date, about 94 MCs affecting the jaws have been reported. Of them, 28 cases affected pediatric patients, which appear to have a favorable prognosis. Herein, we report an additional maxillary MC. Case Description: A 9-year-old boy was referred presenting an asymptomatic and expansive mass in the left maxilla with six months of evolution. CT scans revealed an expansile osteolytic lesion with granular irregularly shaped calcifications invading the nasal and orbital cavity and infiltrating the maxillary sinus with destruction of its posterolateral wall. Microscopic examination revealed dense sheets of small to medium-sized, poorly differentiated round cells arranged in hemangioperycitoma-like vascular pattern surrounded by nodules of mature cartilage. Immunopositivity for vimentin, S100, and CD99 were observed. Diagnosis and Treatment: The final diagnosis was MC. After neoadjuvant chemotherapy, partial maxillectomy was performed. Currently, with 13 years of follow-up, the patient remains well, with no evidence of recurrence or metastasis. Conclusion The current case emphasizes that MC affecting pediatric patients with maxillary location appears to be associated with an indolent course and favorable prognosis.

Proliferative verrucous leukoplakia (PVL) is a non-homogenous type of oral leukoplakia, characterized by multifocal white plaques, propensity to recur after treatment, with strong tendency towards malignant transformation. Interestingly, some studies show that, at initial stages, PVL may resemble oral lichen planus (OLP), potentially leading to misdiagnosis. A 52-year-old woman, with a previous OLP diagnosis, was referred to our service for implant installation and follow-up of OLP lesions. After clinicopathological re-evaluation, a diagnosis of PVL (early stage) was made, and a maxillary full-arch implant-supported prosthesis supported by implants was installed. After 6 years of follow-up, the patient developed squamous cell carcinoma around the implants. The current case emphasizes that PVL patients with oral lesions suggesting peri-implantitis or peri-implant mucositis deserve a more meticulous investigation.