Anti-epidermal growth factor receptor targeted therapy-associated ulcerations.

The well-studied role of epidermal growth factor receptor (EGFR) in metastatic colorectal cancer (mCRC) and non-small cell lung cancer (NSCLC) has enabled the development of drugs that target this molecule, including panitumumab for the former and osimertinib for the latter. Oral adverse events due to those agents are rarely described in the literature and their exact characterization is hampered by inadequate reporting and/or incorrect terminology used. We report two cases of panitumumab- and osimertinib-associated oral ulcerations with emphasis on their possible pathogenesis and optimal management.

Expression of BMP4 and FOXN1 in orthokeratinized odontogenic cyst compared to odontogenic keratocyst suggests an epidermal phenotype.

Odontogenic keratocysts (OKC) and orthokeratinized odontogenic cysts (OOC) are odontogenic cysts that share histological and immunohistochemical similarity with epidermal appendages and cutaneous cystic lesions despite exhibiting contrasting biological behavior. In epidermal appendages, BMP4 induces expression of FOXN1, which participates in terminal differentiation of keratinocytes and control of proliferation. We compared BMP4 and FOXN1 expression in OOC and OKC to investigate their role in the epithelial differentiation of these cysts. BMP4 and FOXN1 expression was assessed using immunohistochemistry in 20 primary sporadic OKC and compared to 16 OOC. BMP4 epithelial expression was detected in 81.25% OOC compared to 35% in OKC, while its expression in connective tissue was observed in 65% OKC and 75% OOC. FOXN1 was detected in 75% OOC vs. 30% OKC. The "triple positive" phenotype, i.e., BMP4 epithelial and connective tissue positivity and FOXN1 epithelial positivity, was seen in 56.25% OOC compared to 10% OKC. The greater expression of BMP4 and FOXN1 in OOC suggests greater activation of this pathway in OOC, which suggests a role in its more mature epithelium; it also resembles an epidermal phenotype.

Base of tongue metastasis of cutaneous malignant melanoma with rhabdoid and neuroendocrine features: Report of a rare case and review of the literature.

Metastatic malignant melanoma (MM) represents a highly aggressive cancer associated with overall poor prognosis. Various anatomic sites can be affected, including the oral cavity and the oropharynx. It may mimic other entities by assuming a variety of clinical appearances and exhibiting a plethora of microscopic variations. Herein, we present a case of a 63-year-old male with a MM metastasizing to the base of tongue, which developed 5 years after the original diagnosis and treatment of cutaneous MM of the chest and heralded its relapse; subsequently, neurological symptoms developed as a result of metastasis to the brain. Diagnostic challenges were encountered, as the tongue lesion clinically masqueraded as a pedunculated reactive lesion and microscopically displayed unusual rhabdoid and neuroendocrine features. Tumor cells expressed S-100, HMB-45, Melan-A, and SOX-10, while most cells with rhabdoid morphology were also positive for myogenin and Myo-D1. Chromogranin and synaptophysin positivity was further noticed in a subset of cells, suggestive of focal neuroendocrine differentiation. Molecular investigation revealed mutations for the BRAF V600E gene. Divergent differentiation of tumor cells may cause diagnostic pitfalls necessitating thorough immunohistochemical analysis. The presence of rhabdoid features and neuroendocrine differentiation are very uncommon, while their co-existence is extremely rare. Better characterization of such microscopic variations in MMs with evaluation of their potential biologic significance is warranted.

The immunohistochemical profile of basal cell nevus syndrome-associated and sporadic odontogenic keratocysts: a systematic review and meta-analysis.

OBJECTIVES: To provide a systematic review of the literature on studies comparing the immunoprofile of nevoid basal cell carcinoma syndrome (BCNS)-associated and sporadic odontogenic keratocysts (OKCs), in order to identify markers that could accurately distinguish the two OKC subtypes. MATERIALS AND METHODS: We searched MEDLINE/Pubmed, Web of Science, EMBASE via OVID, and grey literature for publications until December 28th, 2019, that compared the immunohistochemical expression of the two OKC subtypes. The studies were qualitatively assessed using the Critical Appraisal Tool for Case Series (Joana Briggs Institute). Sensitivity and specificity, positive and negative likelihood ratio, diagnostic odds ratio and area under the curve, and pooled estimates were calculated, using a random-effects model. RESULTS: Seventy-one studies were qualitatively analyzed; 61 markers were evaluated in one study and 32 in ≥ 2 studies. Twenty-five studies reported differential expression of 29 markers in the form of higher number of positive cells or greater staining intensity usually in BCNS-associated OKCs. Meta-analysis for bcl-2, Cyclin D1, CD56, CK18, p53, and PCNA showed that none of those markers is distinguishable between BCNS-associated and sporadic OKCs, in a 95% confidence interval. The risk of bias was high in 34 studies, moderate in 22, and low in 15. CONCLUSIONS: The present systematic review and meta-analysis uncovered that, although several immunohistochemical markers might characterize the OKC phenotype, they cannot discriminate between the BCNS-associated and sporadic OKCs. CLINICAL RELEVANCE: This study highlighted the requirement for additional screening for markers by immunohistochemistry, preferentially coupled to alternative diagnostic applications such as genomics technologies.

Extranodal NK/T Cell Lymphoma, Nasal Type with Palatal Involvement: A Rare Case Report and Literature Review.

T-cell lymphomas are infrequently encountered in the head and neck area, with the most common subtype being Extranodal NK/T cell lymphoma, nasal type (ENKTL-NT). ENKTL-NT shows a predilection for midline facial structures presenting with ulcerative destructive lesions, whereas palatal involvement is one of the most prominent signs from the oral cavity. Herein, we describe a case of a 76-year-old Greek man with nasal obstruction and an extensive painful necrotic ulcer with ragged borders on the left distal portion of the soft palate and palatine tonsil of 4-months duration. After an initial non-diagnostic biopsy from the nasopharynx, a second incisional biopsy from the palatal lesions was performed. Histopathology was suggestive of an angiocentric lymphoproliferative neoplasm and immunohistochemical examination and in situ hybridization for EBV RNA led to a final diagnosis of ENKTL-NT. The patient was placed under combined chemotherapy and radiotherapy and no recurrence has been noted. Additionally, a retrospective review of the cases in the English literature with an established diagnosis of ENTKL-NT between 2000 and 2019, based on the latest WHO classification of Head and Neck tumors, is performed.

Demographic and Clinical Characteristics of 5294 Jaw Cysts: A Retrospective Study of 38 Years.

The aim of the present study is to report the demographic and clinical characteristics of all jaw cysts diagnosed in a single Oral Pathology Department. 5294 cases of jaw cysts diagnosed during a 38-year period were retrospectively collected and classified according to the latest classification of Head and Neck Tumors of the World Health Organization. The patients' gender and age, as well as the main clinical features of the cysts were retrieved from biopsy report forms. Jaw cysts were more common in male patients, with a male to female ratio of 1.6:1. Most patients were in the 4th-6th decade of life, with a mean age of 42.3 ± 16.1 years. There was no jaw predilection and the majority of lesions were more commonly encountered in the anterior region of the maxilla, followed by the molar region of the mandible. The most common jaw cyst was radicular cyst followed by dentigerous cyst, residual cyst and odontogenic keratocyst. The majority of jaw cysts are of inflammatory origin and represent a sequale of pulp necrosis. However, other type of jaw cysts may also be found.

Oral ulceration with bone sequestration: Retrospective study of eight cases and literature review.

OBJECTIVE: Oral ulceration with bone sequestration (OUBS) describes a site-specific intraoral ulcer that covers exposed, non-vital bone in patients lacking any etiological factor known to induce osteonecrosis. We aimed to conduct a retrospective study of eight new cases of OUBS and review the literature. SUBJECTS AND METHODS: This is a retrospective study of OUBS cases, diagnosed and managed during 2007-2017. Inclusion criteria were the presence of oral ulcer with exposed non-vital bone at sites of bone prominence and the absence of any factor known to cause osteonecrosis. The English literature was reviewed on original OUBS cases. RESULTS: Eight patients (5 males and 3 females, aged 27-75 years) were diagnosed with OUBS during years 2007-2017. Four cases involved the mandibular mylohyoid ridge, one a mandibular anterior exostosis and three the maxillary buccal/palatal exostoses. Exposed bone was removed under local anesthesia, resulting in complete healing in all cases. The literature review yielded 32 OUBS cases in the mandible. CONCLUSION: Oral ulceration with bone sequestration is a distinct, probably under-reported rather than rare clinical entity that should be regarded the provisional diagnosis in case of an oral ulcer covering exposed, non-vital bone at sites of bone prominence in patients lacking any etiological factor known to induce osteonecrosis.