ABSTRACT Lipomas are mesenchymal neoplasms relatively uncommon in the oral cavity. Lipomas can exhibit histopathological features mimicking atypical lipomatous tumors (ALT) or dysplastic lipoma (DL) in the presence of degenerative changes. Relevantly, immunohistochemistry assists in the correct diagnosis. Herein, we present the case of a 54-year-old male with a sessile nodule located on the dorsum of the tongue. The histopathological analysis showed a diffuse, non-circumscribed adipocytic proliferation constituted by cells of variable size containing cytoplasmic vacuoles and displaced nuclei, some resembling lipoblasts supported by fibrous connective tissue stroma. By immunohistochemistry, tumor cells were positive for vimentin, S100, FASN, CD10, and p16. Rb expression was intact. Moreover, CD34, p53, MDM2, and CDK4 were negative. After 2-year of follow-up, no alteration or recurrence was observed. In conclusion, MDM2, CDK4, p53, and Rb immunomarkers can be used reliably to differentiate benign lipoma with degenerative changes from ALT and DL.

ABSTRACT Spindle cell squamous cell carcinoma (SpSCC) is a rare biphasic malignant neoplasm, uncommonly affecting the oral cavity. The SpSCC diagnosis is difficult, especially when it exhibits inconspicuous morphology, inadequate tissue sampling, or association with an exuberant inflammatory reaction. Post-radiotherapy recurrent SpSCC occurring at the same site of conventional SCC is a rare phenomenon. A 59-year-old man was complained of “painful injury on the tongue” with 20 days of duration. He reported smoking and alcohol consumption. Medical history revealed conventional SCC on the tongue treated with surgery and radiotherapy 10 years ago. Intraoral examination showed a polypoid lesion with ulcerated areas, measuring 3 cm in diameter, on the tongue and floor of the mouth, at the same site of previous conventional SCC. The microscopical analysis showed small foci of carcinomatous component admixed with an exuberant inflammatory reaction. Immunohistochemistry highlighted the sarcomatoid component. Both malignant components were positive for EMA, CD138, p40 (deltaNp63), p63, and p53. Moreover, CK AE1/AE3 evidenced the carcinomatous component, whereas vimentin stained the sarcomatoid component. The Ki-67 was >10%. The current case emphasizes the importance of immunohistochemistry in the differential diagnosis of SpSCC from mimics and documents a rare complication of Ionizing Radiation.

ABSTRACT Squamous odontogenic tumor (SOT) is a rare benign neoplasm of the jaw that likely arises from remnants of the dental lamina. It is a slow-growing lesion, with a radiolucent appearance in the central variant. Microscopically, SOT shows islands of squamous epithelium supported by fibrous stroma. In rare cases, squamous odontogenic tumor-like proliferation (SOT-LP) can be observed arising from odontogenic cysts (SOT-LPOC). Herein, we describe the case of a 42-year-old man who presented with discreet bleeding in the maxillary gingiva. Imaging revealed a well-defined, ovoid-shaped lesion with sclerotic margins involving tooth #18 in the intraosseous location. Fine needle aspiration supported the cystic nature of the lesion. After surgery, microscopy revealed a dentigerous cyst showing SOT-LP features. There was no recurrence after a 3-year follow-up. To the best of our knowledge, this is the first report of a dentigerous cyst showing SOT-LP features in the maxilla. Such cysts should be identified to avoid misdiagnosis, with the finding having therapeutic and prognostic implications.

ABSTRACT Lymphoepithelial-like carcinoma (LEC) is a rare malignant neoplasm, which can be associated with Epstein-Barr virus (EBV) infection. Histologically, LEC is an undifferentiated carcinoma with an intermixed reactive lymphoplasmacytic infiltrate. LEC appears to be an uncommon tumor type of lip carcinoma. An 82-year-old white woman presented a lesion on her lower lip that developed over the last year. The lesion was characterized by ulceration with flat edges, hardened base, painful, and absence of regional lymphadenopathy. Microscopical analysis evidenced an intense inflammatory infiltrate, composed of lymphoplasmacytic cells, associated with scarce pleomorphic epithelial cells. Immunohistochemistry highlighted the LEC cells with strong expression of pan-CK AE1/AE3, EMA, p63, and p53. CD138 was also faintly positive. Ki-67 was >85%. In situ hybridization analysis did not show evidence of EBV. A diagnostic of EBV-negative LEC was made. We present an uncommon type of lip carcinoma, which can represent a diagnostic challenge for clinicians and pathologists.

RESUMO A acantose glicogênica é uma condição benigna, comumente observada durante procedimentos endoscópicos em pacientes idosos, e se apresenta como placas brancas levemente elevadas, freqüentemente encontrada no terço inferior do esôfago. Microscopicamente, a acantose glicogênica é composta por epitélio escamoso hiperplásico com depósitos de glicogênio intracitoplasmático. A acantose glicogênica extra-esofágica é extremamente rara, com apenas três relatos de casos na literatura em língua inglesa. Apresentamos um caso com uma lesão branca diagnosticada como acantose glicogênica, localizada na borda póstero-lateral esquerda da língua, afetando um paciente do sexo masculino de 56 anos. A história médica não foi contribuitória e o paciente não apresentou lesões durante o exame endoscópico do esôfago, estômago e duodeno superior. A acantose glicogênica é uma condição benigna, que deve ser incluída no diagnóstico diferencial na avaliação de lesões brancas orais. É importante também reconhecer precocemente essa condição benigna e descartar a possibilidade de outras doenças mais graves, porém mais estudos são necessários para melhor definir seu potencial de persistência ou recorrência, como observado no presente caso.

ABSTRACT Glycogenic acanthosis is a benign condition, commonly observed during endoscopic procedures in older patients, which present as slightly elevated whitish plaques often on the lower third of the oesophagus. Microscopically, glycogenic acanthosis is composed of hyperplastic squamous epithelium with intracytoplasmic glycogen deposits. The extraoesophageal glycogenic acanthosis is extremely rare, with only three case reports in the English-language literature. We report a white lesion showing glycogenic acanthosis-like features located on the left posterolateral border of the tongue, affecting a 56-year-old male patient. The medical history was non-contributory and the patient did not show any lesions during endoscopic examination of the oesophagus, stomach, and upper duodenum. Glycogenic acanthosis is a benign condition, which should be included in the differential diagnosis when assessing oral white lesions. It is important also to recognize this benign condition early and rule out the possibility of other more severe diseases, but further studies were necessary for better define their potential for persistence or recurrence, as observed in the current case.