Scrape cytology in rare case of hairy tongue.

Hairy tongue (HT) is a benign condition that causes concern over its abnormal appearance. HT is most commonly seen in adults and is seen as an abnormal coating of the tongue due to hyperkeratosis of filiform lingual papillae. Cytological scraping of the lesion on the tongue was done which showed squamous cells, extraneous material, bacterial colonies, fungal bodies, and hair-like projections, which are the hall mark of the disease. We present a case along with its scrape cytology findings.

Introduction

Numerous oral mucosal lesions are quite frequently encountered, the two most common hairy lesions of the human tongue being hairy leukoplakia and hairy tongue.[1] These two conditions need to be differentiated because of their different clinical, histopathological, and biological behavior.[2]

Hairy tongue (HT)(lingua villosa)is the name given to a benign condition characterised by a hair-like coating on the dorsum of the tongue. The color of the coating, though variable, is often brownish-black and hence, is referred to as black hairy tongue (lingua villosa nigra).[3] Although usually asymptomatic, anxiety over this condition prompts the patient to seek medical advice. Various etiological factors have been associated with this condition.

We present here a rare case of HT where scrape cytology helped in its rapid diagnosis.

Case Report

A 52 year-old male patient presented with a hairy coating on the tongue that he had observed for the past 15 days. Besides the grotesque appearance of the tongue, the hairy coating neither caused any hindrance in swallowing nor any abnormal sensation. The patient gave a history of persistence of growth in spite of repeated attempts to scrape it off. The only other relevant history was that he was a chronic tobacco-chewer. The patient was HIV-negative and was not on any medicines like erythromycin, anti-glaucoma drugs, or steroids.

Examination revealed a brownish-black hairy growth on the posterior third of the dorsum of the tongue [Figure 1]. The hairy projections were approximately one centimetre in length; the central part of the tongue was heavily coated. Scrape cytology had been advised by the referring clinician to rule out any malignant potential of this unusual condition. No draining lymph nodes were palpable but poor oral hygiene and halitosis was noted on examination.

Figure 1

Hairy tongue. Arrow showing hairy growth on posterior third of dorsum of the tongue

Scrape smears were prepared using a wooden spatula. When performing the scrape, it was noted that while superficial material could be easily scraped off, the hairy projections were firmly adherent to the site. A few smears were wet-fixed and the others were air-dried. The wet-fixed smears were stained with hematoxylin and eosin and Papanicolaou (Pap) stains; one air-dried smear was stained with May-Grünwald-Giemsa stain. The remaining air-dried smears were stored for future use. The scrape smears showed abundant cellularity consisting of many normal-appearing squamous cells. Squamous cells did not show any nuclear enlargement, multinucleation, pleomorphism, or perinuclear halo. Many bacterial colonies and fungal bodies were evident along with abundant extraneous material in the background. Some prominent, elongated, hair-like structures, the hall mark of this disease, were also noted [Figure 2]. Periodic acid Schiff (PAS) stain confirmed the fungal bodies whereas Gram stain showed many gram-positive bacterial colonies.

Figure 2

Scrape smears from the hairy lesion on the tongue: squamous cell with bacterial colonies, fungal bodies (Pap, ×1000). Inset: hair-like structure, the hall mark of this disease (Pap, ×100)

Discussion

Human filiform papillae present on the tongue have a complex morphology. Normally, each papilla is approximately one millimetre in length and has a dome-shaped, primary papilla that is surmounted by three to eight elongated secondary papillae. The secondary papillae are composed of a central column of epithelial cells that express hair-type keratin. Defective desquamation of these cells along with their marked retention, results in the formation of the “hairs” which are the hallmark of this disease. Thus, the hairs seen in hairy tongue, that may measure even more than 15 mm in length, are highly elongated and cornified filiform papillae.[4] Normal papillae, which are minimally keratinised, appear pinkish-white. However, hair may appear in a variety of hues (brown, black, white, green, pink) depending on pigments retained from various food stuffs, beverages, or personal habits.[35] In the present case, the patient was a chronic tobacco-chewer which probably led to the brownish-black color of the hairs.

Bacterial and fungal overgrowth have also been thought to play a role in the color of hairy tongue.[5] The prevalence of hairy tongue varies widely, with adult males being more commonly affected.[6] However, hairy tongue was reported in a two month-old infant.[7] Of the various etiological factors associated with this condition, poor oral hygiene and chronic tobacco use were noted in the present case. Besides these, other social habits such as heavy drinking of coffee, tea, use of mouthwashes, drugs like long-term, oral erythromycin, tropical or systemic antibiotics, and steroids have also been implicated.[3568]

In the present case, halitosis that was noted during examination was probably due to entrapped food debris and the bacterial and fungal overgrowth between the elongated papillae. While performing the scrapes, this was the material that could be easily scraped off along with few papillae. This also correlated with the microscopic features of the presence of the abundant extraneous material, bacteria, and fungal bodies.

Although usually asymptomatic, complaints due to the hairy growth range from halitosis and altered taste to tickling or gagging sensation and nausea. The condition may occasionally be very persistent, as was observed in this case where repeated attempts to remove the growth proved futile. However, cure has been reported with application of 40% solution of urea, scraping, topical triamcinolone acetonide, gentian violet, thymol, salicylic acid, vitamin B complex, and in very persistent cases, surgical excision of the papillae.[39]

Hairy tongue needs to be differentiated from oral hairy leukoplakia, especially in patients who are HIV-positive. Besides, oral hairy leukoplakia which is caused by Epstein-Barr virus shows ballooned epithelial cells with a distinct perinuclear halo.[10]

This case, along with its cytological details, is being reported to create awareness of this unusual condition. Although benign, it creates concern due to its grotesque appearance.