Florid follicular lymphoid hyperplasia of the palate: review of the literature and report of an illustrative case.

OBJECTIVE: The aim of this report is to review oral FLH, with emphasis on palatal lesions. METHOD AND MATERIALS: A comprehensive search was performed on PubMed for case reports and case series of palatal FLH published in the English language literature. Relevant data from collated articles was sought, including patient demographics, clinical manifestations, imaging modalities and findings, comorbidities, etiopathogenesis, lesional management, and lesional outcome. A new palatal case has also been provided to illustrate several features of this lesion. RESULTS: In total, 32 cases were assembled to establish clinicopathologic correlations, representing the largest aggregation of published cases. Most of the affected patients were at least 60-years old and with a decisive female predilection. The majority of lesions were ≤ 3 cm, appearing as normal color, purple-red or red, and varied from soft to firm. Notably, 32% of palatal FLHs were associated with denture wear and lesional recurrence was recorded in 16% of cases. To date, none of the reported cases of palatal FLH has undergone malignant transformation. CONCLUSIONS: Palatal FLHs often arise as a reactive process. Critical histopathologic and histochemical assessments are necessary to establish benignity. Postoperatively, clinicians should follow patients for at least 5 years for recurrence and remain vigilant for neoplastic change as several published accounts of non-oral FLHs have undergone malignant transformation, usually to lymphoma.

Expression of PD-L1 and p-RPS6 in epithelial dysplasia and squamous cell carcinoma of the oral cavity.

Introduction: Oral squamous cell carcinoma (OSCC) is often preceded by oral epithelial dysplasia (OED). The role of ribosomal protein S6 (RPS6) and programmed cell death ligand-1 (PD-L1) in the progression of OED to OSCC remains unclear. This study aimed to investigate the expression of phosphorylated RPS6 (p-RPS6) and PD-L1 in OSCC and OED and to examine its relationship with clinicopathological features. Methods: Fifty-two OSCC and 48 OED cases were recruited for immunohistochemical analysis of p-RPS6 and PD-L1 expression. The expression of markers was correlated with clinicopathological features of OSCC and OED. Results: We found p-RPS6 expression in all cases of OSCC and OED, whereas PD-L1 was expressed in 42/48 (87%) OED and in 28/52 (53%) OSCC. The patients with mild OED presented higher expression level of PD-L1 and p-RPS6 significantly, when compared to moderate-differentiated OSCC patients (p < 0.05). Moreover, we found a significant positive correlation between PD-L1 and p-RPS6 expression in OED and OSCC patients (p < 0.01). The PD-L1 expression was significantly related to more than 2 cm tumor size in OSCC patients (p = 0.007). Discussion: Our findings suggest the upregulation of PD-L1 may be related with activation of the mTOR pathway in the early events of tumor progression and the pathogenesis of OSCC.

Diminutive compound odontoma in a child: a case report with emphasis on early detection.

The odontoma is regarded as a hamartomatous process of the jaws. Most are discovered as an incidental radiographic finding, averaging 15 mm in size. This report describes a case of a diminutive odontoma that was surgically removed before the onset of eruptive and pathologic consequences. A compilation of documented complications and syndromes associated with odontomas is also presented.

Immuno-oncologic signature of malignant transformation in oral squamous cell carcinoma.

OBJECTIVE: The purpose of this study is to identify the immuno-oncologic (IO) signature at the surgical tumor margin (TM) of oral squamous cell carcinoma (OSCC) that is involved in the process of malignant transformation. STUDY DESIGN: Under institutional review board approval, TM of 73 OSCC were investigated using immunohistochemistry for the immune biomarker, programmed death ligand-1 (PD-L1). NanoString 770 IO-focused gene set was analyzed in 5 pairs of TM and invasive tumor (T). PD-L1 regulation in response to interferon-gamma (IFN-γ) was investigated in an oral potentially malignant cell line (OPMC). RESULTS: Programmed death ligand-1 expression in the epithelial margin directly correlated with its expression in the underlying immune cells (P = .0082). Differential gene expression showed downregulation of PD-L1 and IFN-γ 6 gene signature in the TM relative to T pair.CD8 and macrophages were higher in TM. CNTFR, LYZ, C7, RORC, and FGF13 downregulation in T relative to TM. TDO2, ADAM12, MMP1, LAMC2, MB21D1, TYMP, OASL, COL5A1, exhausted_CD8, Tregs,and NK_CD56dim were upregulated in T relative to TM. Finally, IFN-γ induced upregulation of PD-L1 in the OPMC. CONCLUSIONS: Our work suggests a role for IFN-γ in PD-L1 upregulation in OPMC and presents novel IO transcriptional signatures for frankly invasive OSCC relative to TM.

Plasma Cell Gingivitis and Its Mimics.

Plasma cell gingivitis (PCG) is an inflammatory condition that affects the gingival mucosa of the oral cavity. It is characterized by polyclonal dense plasma cell infiltrate in the connective tissue. Lesions do not respond to prophylactic treatment. Etiology is most likely hypersensitivity to certain antigens (eg, toothpastes, oral rinses, chewing gums, spices). Differential diagnosis of PCG includes reactive, granulomatous, and neoplastic lesions. The diagnostic workup is based on patient's history and the clinicopathologic correlation to rule out mimics of PCG. Dermatologic patch test may be indicated in chronic conditions to identify the allergen.

Cytokine profiling in plasma distinguishes the histological inflammatory subtype of head and neck squamous cell carcinoma and a novel regulatory role of osteopontin.

Head and neck squamous cell carcinoma (HNSCC) can be classified according to the histological inflammatory subtype (HIS) into inflamed (HIS-INF) or immune excluded (HIS-IE). HIS-IE was previously associated with higher levels of soluble Semaphorin 4D (HsS4D) in plasma, and higher transcriptional levels of osteopontin (OPN) in the tumor tissue, compared to HIS-INF. The goal of the current study is to investigate whether the HIS inflammatory subtype can be distinguished by a differential cytokine panel in peripheral blood. Retrospectively collected five HIS-INF and five HIS-IE tumor tissue with paired plasma were included in the study. Five healthy donors (HD) and five autoimmune/chronic inflammatory conditions (AI/CI) were controls. The ELISA-Luminex™ system was used to detect 40 traditional cytokines in plasma. Human cytokine array (104 cytokines) was used for the conditioned medium (CM) of the HNSCC HN6 cell line. Semaphorin 4D (Sema4D) siRNA and recombinant human osteopontin (rh-OPN) were used to investigate the effect of OPN on Sema4D expression. The HIS-IE cytokine profile was higher than HIS-INF but comparable to AI/CI. HIS-INF had the lowest cytokine levels. HIS-IE was differentially higher in IP-10 and IL8 compared to HD, while HIS-INF was higher in IL-10. Sema4D inhibition in HN6 resulted in a decrease of OPN in the CM of HN6, and treatment with rh-OPN rescued Sema4D in HN6 cell lysate and associated CM. In conclusion, the current work demonstrates a novel association between the HIS subtypes and a differential pattern of cytokine expression in plasma. These findings can open new avenues for HNSCC patient stratification and hence provide better personalized treatment.

Ghost Cell Odontogenic Carcinoma Arising in a Previous Calcifying Odontogenic Cyst: A Case Report and Review of Literature.

Ghost cell odontogenic carcinoma (GCOC) is a rare malignant tumor of odontogenic origin, with only about 50 cases reported in the English literature so far. Histologically, it is characterized by ghost cells, dentinoid deposits, high grade malignant cellular features, and areas of necrosis and invasion. Having common histological features with other odontogenic ghost cell lesions (OGCL) like calcifying odontogenic cyst (COC) and dentinogenic ghost cell tumors, it is crucial to recognize GCOC malignant features, as it can be destructive and invasive, sometimes showing distant metastases and high recurrence rate. For this reason, it may entail more aggressive surgical approach and multimodal therapeutic regimen. Here we present a case report of GCOC arising in a previous COC, treated with surgical excision that showed persistence and recurrence after two years. The clinical and histological features of this rare occurrence are presented, in addition to the surgical approach, and a summary of literature review of OGCL.

Understanding the complex pathogenesis of oral cancer: A comprehensive review.

The pathogenesis of oral cancer is a complex and multifactorial process that requires a deep understanding of the underlying mechanisms involved in the development and progress of malignancy. The ever-improving comprehension of the diverse molecular characteristics of cancer, the genetic and epigenetic alterations of tumor cells, and the complex signaling pathways that are activated and frequently cross talk open up promising horizons for the discovery and application of diagnostic molecular markers and set the basis for an era of individualized management of the molecular defects underlying and governing oral premalignancy and cancer. The purpose of this article is to review the key molecular concepts that are implicated in oral carcinogenesis, especially focusing on oral squamous cell carcinoma, and to review selected biomarkers that play a substantial role in controlling the so-called "hallmarks of cancer," with special reference to recent advances that shed light on their deregulation during the different steps of oral cancer development and progression.

Deletion Mutants of Francisella Phagosomal Transporters FptA and FptF Are Highly Attenuated for Virulence and Are Protective Against Lethal Intranasal Francisella LVS Challenge in a Murine Model of Respiratory Tularemia.

Francisella tularensis (Ft) is a Gram-negative, facultative intracellular bacterium that is a Tier 1 Select Agent of concern for biodefense for which there is no licensed vaccine. A subfamily of 9 Francisella phagosomal transporter (fpt) genes belonging to the Major Facilitator Superfamily of transporters was identified as critical to pathogenesis and potential targets for attenuation and vaccine development. We evaluated the attenuation and protective capacity of LVS derivatives with deletions of the fptA and fptF genes in the C57BL/6J mouse model of respiratory tularemia. LVSΔfptA and LVSΔfptF were highly attenuated with LD50 values of >20 times that of LVS when administered intranasally and conferred 100% protection against lethal challenge. Immune responses to the fpt mutant strains in mouse lungs on day 6 post-infection were substantially modified compared to LVS and were associated with reduced organ burdens and reduced pathology. The immune responses to LVSΔfptA and LVSΔfptF were characterized by decreased levels of IL-10 and IL-1ß in the BALF versus LVS, and increased numbers of B cells, αß and γδ T cells, NK cells, and DCs versus LVS. These results support a fundamental requirement for FptA and FptF in the pathogenesis of Ft and the modulation of the host immune response.

Soluble Sema4D in Plasma of Head and Neck Squamous Cell Carcinoma Patients Is Associated With Underlying Non-Inflamed Tumor Profile.

Semaphorin 4D (Sema4D) is a glycoprotein that is expressed by several tumors and immune cells. It can function as a membrane bound protein or as a cleaved soluble protein (sSema4D). We sought to investigate the translational potential of plasma sSema4D as an immune marker in plasma of patients with head and neck squamous cell carcinoma (HNSCC). Paired peripheral blood and tumor tissue samples of 104 patients with HNSCC were collected at the same time point to allow for real time analysis. Scoring of the histological inflammatory subtype (HIS) was carried out using Sema4D immunohistochemistry on the tumor tissue. sSema4D was detected in plasma using direct ELISA assay. Defining elevated sSema4D as values above the 95th percentile in healthy controls, our data showed that sSema4D levels in plasma were elevated in 25.0% (95% CI, 16.7-34.9%) of the patients with HNSCC and showed significant association with HIS immune excluded (HIS-IE) (p = 0.007), Sema4D+ve tumor cells (TCs) (p = 0.018) and PD-L1+ve immune cells (ICs) (p = 0.038). A multi-variable logistic regression analysis showed that HIS was significantly (P = 0.004) associated with elevated sSema4D, an association not explained by available patient-level factors. Using the IO-360 nanoString platform, differential gene expression (DGE) analysis of 10 HNSCC tumor tissues showed that patients with high sSema4D in plasma (HsS4D) clustered as IFN-γ negative tumor immune signature and were mostly HIS-IE. The IC type in the HsS4D paired tumor tissue was predominantly myeloid, while the lymphoid compartment was higher in the low sSema4D (LsS4D). The Wnt signaling pathway was upregulated in the HsS4D group. Further analysis using the IO-360, 770 gene set, showed significant non-inflamed profile of the HsS4D tumors compared to the LsS4D. In conclusion, our data reveals an association between sSema4D and the histological inflammatory subtype.

Considerations for treatment duration in responders to immune checkpoint inhibitors.

Immune checkpoint inhibitors (ICIs) have improved overall survival for cancer patients, however, optimal duration of ICI therapy has yet to be defined. Given ICIs were first used to treat patients with metastatic melanoma, a condition that at the time was incurable, little attention was initially paid to how much therapy would be needed for a durable response. As the early immunotherapy trials have matured past 10 years, a significant per cent of patients have demonstrated durable responses; it is now time to determine whether patients have been overtreated, and if durable remissions can still be achieved with less therapy, limiting the physical and financial toxicity associated with years of treatment. Well-designed trials are needed to identify optimal duration of therapy, and to define biomarkers to predict who would benefit from shorter courses of immunotherapy. Here, we outline key questions related to health, financial and societal toxicities of over treating with ICI and present four unique clinical trials aimed at exposing criteria for early cessation of ICI. Taken together, there is a serious liability to overtreating patients with ICI and future work is warranted to determine when it is safe to stop ICI.

Canalicular adenoma with unicystic morphology. A rare entity.

BACKGROUND: Canalicular adenoma (CA) is a benign salivary gland tumor (SGT) almost exclusively affecting the minor salivary glands, predominantly of the upper lip, and exhibiting characteristic histopathologic features. As observed in several other SGTs, a commonly encountered finding is the presence of prominent cystic morphology. Even though a multicystic appearance is usually noticed, solitary cystic CAs may rarely occur. CASE REPORT: Two female patients (74 and 78 years old respectively) presented for the evaluation of submucosal asymptomatic masses of the oral cavity. In the 1st case a solitary nodule was noticed in the upper lip, while the 2nd patient exhibited two symmetrical lesions of the buccal mucosae. All three excised specimens displayed cystic morphology upon gross examination. Histopathologically, a solitary cystic formation lined by monomorphic cuboidal or basaloid cells arranged in solid or trabecular patterns was observed in the 1st case. With a differential diagnosis of CA vs basal cell adenoma immunohistochemical examination was performed. Positivity for S-100, CK7 and CD117 (c-kit) and negative reaction for GFAP, p63 and SMA rendered the diagnosis of CA. In the 2nd case both lesions displayed well-circumscribed proliferations by monotonous cuboidal or columnar cells arranged in single cords and occasionally forming beading patterns, while central solitary areas of marked cystic degeneration were noticed. Diagnosis of multifocal unicystic CA was disclosed. DISCUSSION: To our knowledge, only 11 additional cases of unicystic CA have been reported in the English-language literature. Although the exact clinical significance of unicystic morphology in CA is unknown, a tendency for occurrence within the context of multifocal tumors has been detected. Key words:Canalicular adenoma, monomorphic adenoma, unicystic morphology, multifocal tumors, minor salivary glands.

Central compact osteoma of the mandible: case report featuring unusual radiographic and computed tomographic presentations and brief literature review.

Central osteomas of the jaws have been infrequently reported, mostly presenting as a well-defined opacity on conventional radiography projections and as a hyperdensity on computed tomography scans. To increase the knowledge of the phenotypic expression of gnathic central osteomas, an unusual case has been described, including the clinical, radiographic, cone beam computed tomography (CBCT) and histopathologic findings. The lesion was initially discovered 4 years prior as an asymptomatic ovoid radiolucency in the posterior mandible. A 25-year-old female presented with a hyperdense expansile mass with a hypodense rim on a CBCT scan. The enucleated mass was diagnosed as a compact central osteoma. A literature search has identified 4 other cases with similar hypodense borders on CT scans. We propose that a subset of central osteomas should be considered in the differential diagnosis of osteopathologies of the jaws with hyperdense internal architecture and hypodense borders, as seen on CT images.

Combination Nivolumab/Ipilimumab Immunotherapy For Melanoma With Subsequent Unexpected Cardiac Arrest: A Case Report and Review of Literature.

The success of immunotherapy in the treatment of patients with advanced melanoma has paved the way for unprecedented successes in the treatment of many other malignancies. We present a case of extensively metastatic oral mucosal melanoma that responded successfully to combined immune checkpoint blockade with ipilimumab and nivolumab but developed multiple immune-related adverse events, including myocarditis, a rare event associated with immunotherapy of elderly melanoma patients. Though the acute myocarditis was managed successfully, the patient succumbed to sudden cardiac death. This case highlights the fact, that autoimmune carditis must be considered when working up the sudden onset of shortness of breath in patients on immune checkpoint blockade. After controlling the acute myocarditis with high-dose steroids, which should be tapered over 6 weeks, further cardiology care is needed, and a defibrillator might have to be implanted. Understanding the pathophysiology of immune-related adverse events could make cancer immunotherapy both more effective and safer.

Semaphorin 4D in human head and neck cancer tissue and peripheral blood: A dense fibrotic peri-tumoral stromal phenotype.

The search for stromal biomarkers in carcinoma patients is a challenge in the field. Semaphorin 4D (Sema4D), known for its various developmental, physiological and pathological effects, plays a role in pro and anti-inflammatory responses. It is expressed in many epithelial tumors including head and neck squamous cell carcinoma (HNSCC). Recently, we found that HNSCC-associated Sema4D modulates an immune-suppressive, tumor-permissible environment by inducing the expansion of myeloid derived suppressor cells. The purpose of this study was to determine the value of Sema4D as a biomarker for the peri-tumoral stromal phenotype in human HNSCC. Our data showed Sema4D+ve/high tumor cells in 34% of the studied cohort with positive correlation to Stage III (p=0.0001). Sema4D+ve/high tumor cells correlated directly with dense fibrotic peri-tumoral stroma (p=0.0001) and inversely with infiltrate of Sema4D+ve/high tumor-associated inflammatory cells (TAIs) (p=0.01). Most of the Sema4D+ve/high TAIs were co-positive for the macrophage biomarker CD163. Knockdown of Sema4D in WSU-HN6 cells inhibited collagen production by fibroblasts, and decreased activated TGF-ß1 levels in culture medium of HNSCC cell lines. In a stratification model of HNSCC using combined Sema4D and the programmed death ligand 1 (PDL-1), Sema4D+ve/high tumor cells represented a phenotype distinct from the PDL-1 positive tumors. Finally,Sema4D was detected in plasma of HNC patients at significantly higher levels (115.44, ± 39.37) compared to healthy donors (38.60± 12.73) (p <0.0001). In conclusion, we present a novel HNSCC tumor stratification model, based on the expression of the biomarker Sema4D. This model opens new avenues to novel targeted therapeutic strategies.

Central xanthoma of the mandible associated with hyperlipidemia: A rare presentation.

Xanthoma is a common, self-limiting cutaneous lesion of non-Langerhans cell, lipid-laden foamy histiocytes that is often concomitant with hyperlipidemia. The intraosseous counterpart is rarely encountered and typically presents as a painless, expansile osteolytic process in the context of hyperlipidemia or normolipidemia. Only a scant number of gnathic xanthomas have been reported in the otolaryngologic literature. We report the clinical, laboratory, radiographic, histopathologic, immunohistochemical, and ultrastructural studies of a mandibular lesion discovered in an asymptomatic 16-year-old male, and associated with 2 previously unreported comorbidities, namely hyperlipidemia and vitamin D deficiency.

Juvenile Trabecular Ossifying Fibroma.

Benign fibro-osseous lesions within the maxillofacial region represent a heterogeneous group of benign entities with overlapping histologic features. Ossifying fibroma, the rarest of these entities, represents a true neoplasm. Juvenile ossifying fibroma (JOF) is considered an aggressive rapidly growing sub-type. It tends to occur in the first or second decades of life. Based on histological and clinical features it can further be classified into two variants, namely juvenile trabecular ossifying fibroma (JTOF) and juvenile psammomatoid ossifying fibroma (JPOF). JTOF features a proliferation of cellular fibroblastic tissue admixed with woven bone trabeculae with varying histologic presentations. Correlation with clinical and radiographic features is essential to differentiate it from other fibro-osseous lesions. A case of JTOF of the mandible is exemplified in this Sine Qua Non Radiology-Pathology article.

Large Cell Transformation of Oral Mycosis Fungoides.

Mycosis fungoides (MF) accounts for approximately 50% of all primary cutaneous lymphomas. MF occurrence in the oral cavity is extremely rare with approximately 45 cases reported to date. We present a case of a 68 year-old man with a raised nodular lesion of the ventral tongue with clinical impression of irritational fibroma. Histopathologic and immunohistochemical (IHC) examination revealed a phenotype consistent with MF with large cell transformation in the context of Sezary syndrome. The histological diagnosis of oral MF requires a high index of suspicion and IHC panel to rule out large cell transformation. To our knowledge, only four cases of large cell transformation of oral MF have been reported in the English literature. The clinical and histopathologic features of a rare case of intra-oral MF with large cell transformation are exemplified in this article.

Glycogen-Rich Clear Cell Squamous Cell Carcinoma Originating in the Oral Cavity.

Clear cell squamous cell carcinoma (CCSCC) is a rare histological subtype of squamous cell carcinoma (SCC) that was originally described in the skin. Here, we report a case of a 66-year-old female patient who presented with a fungating ulcerative mass of the left lateral tongue extending anteriorly to the floor of the mouth, and posteriorly to the left retromolar fossa and the oropharynx. The patient had a history of SCC of the left posterior tongue that was treated with partial glossectomy and adjuvant radiotherapy. Representative biopsies were obtained from the floor of the mouth, tongue and retromolar fossa. The examined biopsies showed various degrees of dysplastic surface epithelium with transition into infiltrating epithelial tumor nests and cords with clear cytoplasm and malignant cellular features. Pancytokeratin, CK5/6, and p63 were all diffusely positive. S-100, Calponin, and smooth muscle actin (SMA) were negative. PAS stain was diffusely positive and diastase labile in the tumor clear cells. Sparse areas of mucicarmine positivity were noted. Based on these findings a final diagnosis of a glycogen-rich CCSCC was given. This case represents a very rare histological variant of oral SCC, which is significant for the histological differential diagnosis of clear cell tumors of the oral cavity.

Human Head and Neck Squamous Cell Carcinoma-Associated Semaphorin 4D Induces Expansion of Myeloid-Derived Suppressor Cells.

One of the mechanisms by which malignancies can induce immune suppression is through the production of cytokines that affect the maturation and differentiation of inflammatory cells in the tumor microenvironment. Semaphorin 4D (Sema4D) is a proangiogenic cytokine produced by several malignancies, which has been described in the regulation of the immune system. In the present study, we examined the role of human head and neck squamous cell carcinoma (HNSCC)-secreted Sema4D on myeloid cell differentiation. CD33(+) cells cultured in HNSCC cell line-derived conditioned medium differentiated into myeloid derived suppressor cells (MDSC) (CD33(+)CD11b(+)HLA-DR(-/low)). The addition of anti-Sema4D Ab to HNSCC conditioned medium significantly reduced the expansion of the MDSC population. Similarly, knockdown of Sema4D in an HNSCC cell line resulted in a loss of MDSC function as shown by a decrease in the production of the immune-suppressive cytokines arginase-1, TGF-ß, and IL-10 by MDSC, concomitant with recovery of T cell proliferation and IFN-γ production following stimulation of CD3/CD28. Importantly, CD33(+) myeloid and T cells cultured in conditioned medium of HNSCC cells in which Sema4D was knocked down promoted antitumor inflammatory profile, through recovery of the effector T cells (CD4(+)T-bet(+) and CD8(+)T-bet(+)), as well as a decrease in regulatory T cells (CD4(+)CD25(+)FOXP3(+)). We also showed that Sema4D was comparable to GM-CSF in its induction of MDSC. Collectively, this study describes a novel immunosuppressive role for Sema4D in HNSCC through induction of MDSC, and it highlights Sema4D as a therapeutic target for future studies to enhance the antitumorigenic inflammatory response in HNSCC and other epithelial malignancies.