Median Rhomboid glossitis
This condition affects the dorsum of the tongue. Usually it affects the junction between the anterior 2/3 and posterior 1/3 of the tongue. This is a chronic lesion about which very little is known. It usually appears as atrophic, erythematous, depapillated area.
Study of embryology of tongue will help us in understanding this disorder. Embryologically tongue is formed by fusion of two lingual tubercles with the midline structure known as tuberculum impar. Tuberculum impar arises from the first and second branchial arches. Sometimes the point of fusion between the lingual tubercles and tuberculum impar may be defective leaving a rhomboid area on the dorsum of tongue atrophic and devoid of papilla.
This area is highly susceptible to candidiasis. This area is usually erythematous. Erythema is usually caused due to inflammatory changes in the area. This lesion is commonly confused with erythroplakia which is premalignant.
Median rhomboid glossitis occurs in midline of the tongue just posterior to the circumvellate papillae. Usually the lesion measures no more than 2cms in its greatest dimension. This lesion is more common in males. The lesion may appear whitish if there is excess keratin production. If there is associated candida infection, corresponding area of soft palate will show erythema. This phenomenon is known as kissing lesion.
This lesion is usually incidental in nature. If these lesions get infected by candida, then patients may have burning sensation when the patient eats.
This lesion should be differentiated from:
Gumma of tongue
Granular cell tumor
Histological studies of this lesion demonstrate:
Atrophic stratified squamous epithelial lining
Moderately fibrosed stroma with dilated capillaries below squamous lining
Extensively elongated rete process are seen (possibly due to candida infection)
Silver staining may demonstrate candida hyphae
No treatment is usuallynecessary. If there is super added fungal infections then topicalantifungal agents may help. Troublesome lesions can be resectedtotally.