September 2016

Patient presentation:

A 69-year old male patient with a history of benign mucous membrane presented to Dr. Paul Edwards, an oral and maxillofacial pathologist and former faculty at University of Michigan School of (UMSoD), complaining of “new ”. These lesions were asymptomatic.

Intraoral examination revealed bilateral, white, corrugated plaques on the lateral borders of the that did not wipe off. No other intraoral or extraoral lesions were noted.

Figure 1: White lesions on the right (A) and left (B) lateral border of the tongue.

Incisional :

An incisional biopsy was taken and submitted in formalin for histopathological evaluation and DNA hybridization analysis.

Histological Interpretation:

The specimen demonstrated a corrugated hyperparakeratotic surface (black arrow, Fig 2A and 2B) and mild . Although faint intracellular ballooning of epithelial cells was observed (blue arrow, Fig 2B), nuclear beading (clear perinuclear clearing and irregular peripheral margination of nuclear chromatin) was not appreciated in the examined specimen.

Figure 2: Hyperkeratotic and hyperplastic with corrugated parakeratin (black arrows) and faint epithelial cell ballooning (blue arrow)(H&E, A: 10X; B: 20X).

In-situ hybridization of formalin fixed, paraffin- embedded tissue was used to assess the presence of Epstein Barr (EBV) early RNA. In-situ hybridization is a method of detecting and localizing specific mRNA sequences in tissue sections by binding a complementary strand of a nucleotide probe to the sequence of interest. The presence of EBV RNA was identified in the biopsy sample (Figure 3).

Figure 3: Abundant EBV-encoded RNA (blue dots) in the nuclei of the upper spinous cell layer detected by in-situ hybridization (black arrow, 20X).

Differential Diagnosis:

The framework for a differential diagnosis is based on the presentation of an asymptomatic, white plaque that is non-removable and presents bilaterally on the lateral border of the tongue. See Table 1 for the summary of entities in the differential diagnosis for this patient.

Table 1: Differential diagnosis of asymptomatic, white plaques that do not wipe off and present bilaterally on the lateral borders of the tongue.

The clinical presentation combined with histopathological features favor a clinical diagnosis of oral viral (“hairy”) . The patient, previously diagnosed with benign mucous membrane pemphigoid, was in remission with usage of topical steroid, Clobetasol propionate on an as needed basis for new mucosal lesions. With discontinuation of the steroid medicament, the patient subsequently experienced an improvement and resolution of all OVL lesions (Figure 4A- B). Figure 4: Resolution of OVL lesions after discontinuation of topical steroid, Clobetasol, prescribed for other comorbidity. (A: right lateral border of tongue, B: left lateral border of tongue).

Final diagnosis: EBV-associated oral viral leukoplakia

Discussion:

Oral viral leukoplakia (OVL; oral hairy leukoplakia, OHL), is an Epstein-Barr virus (EBV) associated condition that was first described in 1984 by Greenspan et al. in homosexual male patients (Greenspan et al., 1984). Clinically, OVL presents as an asymptomatic and nonremovable, white mucosal plaque that ranges from faint vertical streaks to a thickened keratotic shaggy surface. Typically found on the lateral border of the tongue, on rare occasion the buccal mucosa, soft , and may be involved.

The Epstein-Barr viral infection remains latent in peripheral blood B-lymphocytes in the majority of patients and can reactivate with environmental or patient triggers (Miyashita et al., 1997; Palefsky et al., 2002). Transmission occurs via mucosal secretion, and replication of the virus is seen in normal oral epithelial cells - and more robustly in OVL lesions (Greenspan et al., 1985). Interestingly, although severe immunosuppression in the context of HIV infection is thought to lead to EBV replication, OVL occurs in only 25% of HIV-positive patients, which suggests the influence of other factors on the development of OVL (Diaz-Mitoma et al., 1990). Modulating factors beyond immunosuppression and viral replication, such as host response, local irritants and concomitant infections have been in the pathogenesis of oral viral leukoplakia (Reichart et al., 1989).

EBV has also been associated with other conditions of interest to oral health care professionals, some of which may occur in the context of immunosuppression; for example and EBV-associated lymphoproliferative disease ranging from benign, reactive processes to overt malignancies (Ali et al., 2015; Slots et al., 2006). A strong association exists between EBV infection and Burkitt’s , a B-lymphocyte neoplasm that affects approximately 8 out of 100,000 children in equatorial Africa and Papua New Guinea (Rochford and Moormann, 2015). In addition, EBV infection has also been implicated in nasopharyngeal carcinoma, a neoplasm confined to the nasal passages and throat that is endemic among Cantonese Chinese people in southern China (Yu and Yuan, 2002). While EBV has been implicated in these malignancies, definitive causality has not yet been established (Raab- Traub, 2015).

Despite oral viral leukoplakia being considered a diagnostic and prognostic finding in HIVpositive individuals (Coogan et al., 2005), the condition has also been described in HIV- negative immunocompromised patients: 1) following kidney, heart, liver, and bone marrow transplant; 2) with hematological malignancies such as multiple myeloma; 3) on systemic or topical steroid treatment (Chambers et al., 2015; Prasad and Bilodeau, 2014). In rare cases, OVL has alsobeen described in a number of apparently immunocompetent patients (Eisenberg et al., 1992; Felix et al., 1992; Piperi et al., 2010). Herein, we presented a patient suffering from a concurrent diagnosis of benign mucous membrane pemphigoid, an autoimmune disease that may have contributed to diminished immunocompetency and increased susceptibility to EBV associated OVL, especially in the context of chronic use of topical steroid cream.

Due to its non-specific etiology, OVL should not be regarded as pathognomonic for HIV infection or significant systemic immunosuppression. Incorrect attribution of HIV-positive status to patients can be perceived not only as discriminatory, but also as psychologically damaging, rendering unnecessary feelings of anxiety and fear in patients. For proper management, it is recommended that clinicians gather a thorough medical history, paying close attention to factors suggestive of immunocompromised status, including transplant history, hematologic malignancies and steroid use as previously mentioned. Further referral of patients for medical workup and evaluation of immunocompetence, including assessment of immunoglobin levels, is also suggested for comprehensive care (Prasad and Bilodeau, 2014).

Oral healthcare professionals are expected to provide equal treatment to all patients irrespective of underlying systemic conditions, including but not limited to HIV disease. Discrimination in oral healthcare provision inevitably creates barriers to access to care and negatively influences healthcare seeking behaviors in patients (Alemu et al., 2013; Clair et al., 2016; Sayles et al., 2007). Nevertheless, for patients who are HIV-negative or otherwise lacking obvious predisposing factors for OVL development, a medical consult to include re-evaluation of HIV status is still recommended.

In routine management of patient’s with OVL, most cases do not require treatment. When indicated, treatment is intended for esthetic concerns and to alleviate patient discomfort. Topical therapy recommended for OVL includes podophyllin, a dry alcoholic extract, and acyclovir, an antiviral medicament, although there are few studies that have evaluated the effects of topical treatment in patients with OVL (Brasileiro et al., 2014). Regarding HIV-positive patients who experience OVL, appropriate antiretroviral therapy such as HAART has led to significant reduction in the prevalence of lesions (Patton et al., 2013). Other methods of treatment may include elimination of predisposing factors that may undermine immunocompetence, such as chronic steroid use. In the case presented, reduction of topical corticosteroid use in treatment of other comorbidities led to complete resolution of the OVL lesions.

Clinical diagnosis of OVL is often sufficient and rarely requires biopsy for confirmation. Although OVL exhibits no malignant potential, other white tongue lesions that mimic OVL such as idiopathic leukoplakia need to be carefully distinguished, especially due to their pre- neoplastic nature. Previously thought to afflict only HIV-positive patients, EBV associated OVL is now known to have a multi-factorial etiology and warrants appropriate surveillance and medical treatment of underlying factors that lead to immunocompromised status. Even patients who are otherwise immunocompetent are not shielded from encounters of oral viral leukoplakia.

REFERENCES:

Alemu T, Biadgilign S, Deribe K, Escudero HR (2013). Experience of stigma and discrimination and the implications for healthcare seeking behavior among people living with HIV/AIDS in resource- limited setting. SAHARA J 10(1):1-7.

Ali AS, Al-Shraim M, Al-Hakami AM, Jones IM (2015). Epstein- Barr Virus: Clinical and Epidemiological Revisits and Genetic Basis of Oncogenesis. Open Virol J 9(7-28.

Brasileiro CB, Abreu MH, Mesquita RA (2014). Critical review of topical management of oral hairy leukoplakia. World J Clin Cases 2(7):253-256.

Chambers AE, Conn B, Pemberton M, Robinson M, Banks R, Sloan P (2015). Twenty- firstcentury oral hairy leukoplakia--a non-HIV-associated entity. Oral Surg Oral Med Oral Pathol Oral Radiol 119(3):326-332.

Clair M, Daniel C, Lamont M (2016). Destigmatization and health: Cultural constructions and the long-term reduction of stigma. Soc Sci Med.

Coogan MM, Greenspan J, Challacombe SJ (2005). Oral lesions in infection with human virus. Bull World Health Organ 83(9):700-706.

Diaz-Mitoma F, Ruiz A, Flowerdew G, Houston S, Romanowski B, Kovithavongs T et al. (1990). High levels of Epstein-Barr virus in the oropharynx: a predictor of disease progression in human immunodeficiency virus infection. J Med Virol 31(2):69-75.

Eisenberg E, Krutchkoff D, Yamase H (1992). Incidental oral hairy leukoplakia in immunocompetent persons. A report of two cases. Oral Surg Oral Med Oral Pathol 74(3):332- 333.

Felix DH, Watret K, Wray D, Southam JC (1992). Hairy leukoplakia in an HIV- negative, nonimmunosuppressed patient. Oral Surg Oral Med Oral Pathol 74(5):563-566.

Greenspan D, Greenspan JS, Conant M, Petersen V, Silverman S, Jr., de Souza Y (1984). Oral "hairy" leucoplakia in male homosexuals: evidence of association with both papillomavirus and a herpes-group virus. Lancet 2(8407):831-834.

Greenspan JS, Greenspan D, Lennette ET, Abrams DI, Conant MA, Petersen V et al. (1985). Replication of Epstein-Barr virus within the epithelial cells of oral "hairy" leukoplakia, an AIDSassociated . N Engl J Med 313(25):1564-1571.

Miyashita EM, Yang B, Babcock GJ, Thorley-Lawson DA (1997). Identification of the site of Epstein- Barr virus persistence in vivo as a resting B cell. J Virol 71(7):4882-4891.

Palefsky JM, Berline J, Greenspan D, Greenspan JS (2002). Evidence for trafficking of Epstein- Barr virus strains between hairy leukoplakia and peripheral blood lymphocytes. J Gen Virol 83(Pt 2):317- 321.

Patton LL, Ramirez-Amador V, Anaya-Saavedra G, Nittayananta W, Carrozzo M, Ranganathan K (2013). Urban legends series: oral manifestations of HIV infection. Oral Dis 19(6):533-550. Piperi E, Omlie J, Koutlas IG, Pambuccian S (2010). Oral hairy leukoplakia in HIV-negative patients: report of 10 cases. Int J Surg Pathol 18(3):177-183.

Prasad JL, Bilodeau EA (2014). Oral hairy leukoplakia in patients without HIV: presentation of 2 new cases. Oral Surg Oral Med Oral Pathol Oral Radiol 118(5):e151-160.

Raab-Traub N (2015). Nasopharyngeal Carcinoma: An Evolving Role for the Epstein-Barr Virus. Curr Top Microbiol Immunol 390(Pt 1):339-363.

Reichart A, Langford HR, Gelderblom, et al. Oral hairy leukoplakia: observations in 95 cases and review of the literature. J Oral Pathol Med. 18 (1989): 410–415.

Rochford R, Moormann AM (2015). Burkitt's Lymphoma. Curr Top Microbiol Immunol 390(Pt 1):267- 285.

Sayles JN, Ryan GW, Silver JS, Sarkisian CA, Cunningham WE (2007). Experiences of social stigma and implications for healthcare among a diverse population of HIV positive adults. J Urban Health 84(6):814-828.

Slots J, Saygun I, Sabeti M, Kubar A (2006). Epstein-Barr virus in oral diseases. J Periodontal Res 41(4):235-244.

Yu MC, Yuan JM (2002). Epidemiology of nasopharyngeal carcinoma. Semin Cancer Biol 12(6):421- 429.