Severe oral erosive lichenoid reaction to pembrolizumab therapy.

New advances in cancer immunotherapy have been flooding the market at a rapid rate. Pembrolizumab (Keytruda), a programmed cell death protein 1 inhibitor, introduced in 2014, has been used to treat several cancers. Immune-related adverse events associated with pembrolizumab and other immune checkpoint inhibitors are now well-described complications. We describe the case of a 65-year old female with severe oral lichenoid lesions occurring after treatment with pembrolizumab for bladder cancer. To the best of our knowledge, this is the first report of a biopsy-proven oral erosive lichenoid reaction confirmed through direct immunofluorescence.

Pigmented lateral periodontal cyst: A case report and review of pigmented odontogenic cysts.

Pigmented odontogenic cysts are uncommon and to date, only 37 cases have been reported in the English literature. Here, we report a case of a pigmented lateral periodontal cyst (LPC) in the maxilla of a 48-year-old female. The patient presented with clinical swelling in the maxillary anterior region. Microscopic features of the biopsied specimen were consistent with a diagnosis of LPC. The epithelial cyst lining exhibited numerous coarse granules of melanin pigment, which was confirmed by S-100 immunohistochemistry and Fontana-Masson bleach histochemical method. Almost all documented cases of pigmented odontogenic cysts have occurred in Asians and African-Americans, with only three cases in white patients. Racial pigmentation may have a role in the pathogenesis of these lesions. Although the origin and pathologic significance of melanocytes in these pigmented intraosseous lesions cannot be explained, it may be something to consider for investigation in future.

Denosumab-related osteonecrosis of the jaw: a report of 2 cases and review of the literature.

Bisphosphonates have been implicated in the induction of medication-related osteonecrosis of the jaw (MRONJ) since 2004. Since then, the spectrum of drugs implicated in the onset of MRONJ has broadened to include other antiresorptive and antiangiogenic drugs. Denosumab is an antiresorptive drug that has been on the market since 2010. Denosumab inhibits osteoclast formation, function, and survival and increases bone mineral density. As a result, denosumab is indicated for the treatment of osteoporosis and bone metastases. This article reports 2 cases of MRONJ associated with denosumab use. The characteristics and progression of MRONJ in patients who take denosumab are reviewed, and therapeutic measures are discussed.

Merkel Cell Carcinoma of the Buccal Mucosa and Lower Lip.

Merkel cell carcinoma (MCC) is an uncommon relatively aggressive neuroendocrine dermal neoplasm first described in 1972 as a tumor of the sun exposed skin. Although most MCC affect the skin of the head and neck, rare primarily oral mucosal cases have been documented. Merkel cells are nondendritic neuroendocrine cells that are found not only in the skin but also the oral mucosa and give rise to MCC. Neuroendocrine cells may be found as aggregates in organs or as diffuse or isolated cells within organs and their epithelial lining. They contain peptide hormones and biogenic amines and occur in two forms: dendritic, which are not associated with nerve fibers and non-dendritic, which are associated with nerve fibers. Merkel cells as well as MCC express simple epithelium-type Cytokeratins (8, 18, 19, 20), neurosecretory substances; chromogranin A, synaptophysin, neuron-specific enolase (NSE), adhesion molecules, and villin (intermediate filament). Though weakly, they also express neural markers such as S-100 protein. Cytokeratin 20, and Cluster of differentiation 56, are the two key diagnostic markers for Merkel cells and MCC. Etiology includes UV radiation, the recently described Merkel cell polyomavirus, and long term systemic immunosuppression. The cutaneous and mucosal variants of MCC are considered aggressive tumors with a high risk for local recurrence and metastasis and should be considered in the differential diagnosis of head and neck mucosal lesions. We present two cases of primary Merkel cell carcinoma, one on the buccal mucosa and the other on the lower lip, and discuss the salient histologic, immunohistochemical and clinical features.

White lesions.

Increased thickness of the epithelium imparts a white appearance to the oral mucosa by increasing the distance to the underlying blood vessels. Usually this thickening is a result of the increased formation of keratin. Some other less common causes of white lesions are acanthosis or a thickening of the spinous cell layer, edema of the epithelium, or increased fibrosis of the connective tissue thereby reducing blood vessels. Occasionally the surface of an ulcer may appear white, due to collection of fibrin on the surface. In this article the authors discuss white lesions based on putative etiology, that is, hereditary, reactive, inflammation related, immunologic, traumatic, infection related, and idiopathic.

Gout of the temporomandibular joint: a review of the literature.

BACKGROUND: Gout is a common metabolic disorder that leads to elevated serum uric acid levels and deposition of urate crystals in tissues, leading to conditions such as arthritis and neuropathy. CASE DESCRIPTION: Although the prevalence of gout has been increasing during the past two decades, temporomandibular joint (TMJ) involvement is rare, with only 10 reports in the English-language literature. The authors present a rare case of gout involving the TMJ in a 51-year-old woman. They also review reported cases of gout involving the TMJ, including the clinical, radiographic and microscopic diagnostic criteria. The patient was treated primarily with anti-inflammatory drugs and colchicine but refused to undergo surgery. To date, she continues to be free of symptoms despite the presence of gouty deposits. CLINICAL IMPLICATIONS: Because of its rarity, a clinician may overlook gout involving the TMJ in the differential diagnosis of facial pain even when the patient has received a diagnosis of gout in other joints.

Primary diffuse large B-cell lymphoma of the oral cavity: germinal center classification.

Primary lymphomas of the oral cavity are rare and the most frequent type is diffuse large B-cell lymphoma (DLBCL). Recently, several reports have highlighted the value of classifying DLBCL into prognostically important subgroups, namely germinal center B-cell like (GCB) and non-germinal center B-cell like (non-GCB) lymphomas based on gene expression profiles and by immunohistochemical expression of CD10, BCL6 and MUM-1. GCB lymphomas tend to exhibit a better prognosis than non-GCB lymphomas. Studies validating this classification have been done for DLBCL of the breast, CNS, testes and GI tract. Therefore we undertook this study to examine if primary oral DLBCLs reflect this trend. We identified 13 cases (age range 38-91 years) from our archives dating from 2003-09. IHC was performed using antibodies against germinal center markers (CD10, BCL6), activated B-cell markers (MUM1, BCL2) and Ki-67 (proliferation marker). Cases were sub-classified as GCB subgroup if CD10 and/or BCL6 were positive and MUM-1, was negative and as non-GCB subgroup if CD10 was negative and MUM-1 was positive. Immunoreactivity was noted in 2/13 cases for CD10, in 12/13 for BCL6, in 8/13 for MUM-1, and in 6/13 for BCL2. Therefore, 8/13 (58%) were sub-classified as non-GCB DLBCLs and 5/13 (42%) as GCB subgroup. All tumors showed frequent labeling with Ki-67 (range 40-95%). Four of the 8 patients with non-GCB subgroup succumbed to their disease, with the mean survival rate of 16 months. Two patients in this group are alive, one with no evidence of disease and another with disease. No information was available for the other 3 patients in this group. Four of the 5 patients in the GCB subgroup were alive with no evidence of disease and one patient succumbed to complications of therapy and recurrent disease after 18 months. In conclusion, our analysis shows that primary oral DLBCL predominantly belongs to the non-GCB subgroup, which tends to exhibit a poorer prognosis. These findings could allow pathologists to provide a more accurate insight into the potential aggressive behavior and poorer prognosis of these lymphomas.

Dental erosion due to excessive wine consumption.

Dental erosion can result in serious and irreversible damage to dentition, although it often is not recognized in the early stages. It is important to be aware of the numerous factors that can lead to tooth erosion, as this knowledge forms an important basis for intervention and treatment planning. This article presents a case of dental erosion involving an alcoholic woman who habitually consumed large quantities of white wine and discusses the dental erosion induced by excessive wine consumption. The authors also present the clinical aspects (including different etiologies of erosion) that distinguish extrinsic erosion from intrinsic erosion.

AAOMP Case Challenge: Multiple red plaques with severe burning and soreness on the tongue.

A 68-year-old African-American female presented with very painful lesions of the dorsum and ventral surfaces of the tongue she had endured for at least six months.