Manifestations of Disease of Tongue
As a consequence of the easy accessibility to clinical inspection, the tongue, in the course of medical history, has played a rather special role as a diagnostic indicator of systemic disease. The degree of moisture or dryness of the lingual mucosa may indicate disturbances of fluid balance. Changes in color and the appearance of edema, swelling, ulcers, and inflammation or atrophy of the lingual papillae may represent signs of endocrine, nutritional, hematologic, metabolic, or hepatic disorders, infectious diseases, or aberrant ingestions. On the other hand, it should be recognized that the tongue participates with the gingivae and the buccal mucosa in localized pathologic processes of the oral cavity, and that a number of conditions exist in which the surface or the parenchyma of the tongue itself is exclusively involved.
Fissured tongue is a congenital lingual defect, also called a grooved or scrotal tongue, characterized by deep depressions or furrows, which run primarily in a longitudinal direction starting near the tip and disappearing gradually at the posterior third of the dorsum. Both the length and depth of the furrows vary and can best be demonstrated by stretching the tongue laterally with tongue blades. It has often been observed that the fissures form a leaflike pattern, with a median crack larger than the other furrows. In general, the larger grooves run parallel, with smaller branches directed toward the margin of the tongue. The mucosal lining of the crevices is smooth and devoid of papillae. Most often this condition is asymptomatic; rarely, symptoms are reported, which include mild discomfort when eating spicy or acidic foods or drinks. Occasionally a fissured tongue is incidentally noted in an individual that also has macroglossia or a geographic tongue; there is, however; no intrinsic relationship between these three lingual conditions. Median rhomboid glossitis is a misnomer, because it is not an inflammatory process but a developmental lesion resulting from failure of the lateral segments of the tongue to fuse completely before interposition of the fetal tuberculum impar. It is an oval or rhomboidal, red, slightly elevated area, about 1 cm in width and 2 or 3 cm long, contrasting in color with the surrounding parts of the dorsum. This area is devoid of papillae. Sometimes it may be nodular, mammillated, or fissured. Except for an occasional secondary inflammation, it causes no subjective symptoms. Visual confirmation of this benign lesion will differentiate it from a malignant process, thereby avoiding an unnecessary and costly evaluation. Geographic tongue, otherwise labeled erythema migrans or Butlin’s wandering rash, is a chronic superficial desquamation of obscure etiology seen most often in children. It may, however, recur at intervals throughout life or persist unchanged in degree. The rash is confined to the dorsum of the tongue and appears, rarely, on the inferior surface. The dorsal surface is marked with irregular, denuded grayish patches, from which, at times, the papillae are shed to reveal a dark-red circle of smooth epithelium bordered by a whitish or yellow periphery of altered papillae, which have changed from normal color and are about to be shed in turn. The circles enlarge, intersect, and produce a maplike configuration. The lesions appear depressed compared with the papillated surface and clearly demarcated. Continued observation, which reveals the migratory character of the spots, is necessary to confirm the diagnosis. The geographic tongue may sometimes be fissured or lobulated at the margin, where it contacts the teeth. Hairy tongue, or black tongue, is an acquired discoloration. Thick, yellowish, brownish, or black furry patches, made up of densely matted, hypertrophied filiform papillae, sometimes cover more than half of the dorsal linguae. The surface of the tongue is normally coated with a layer of papillae that serve as taste buds. The tongue also has a protective layer of dead cells known as keratin. Hairy tongue results because of defective desquamation of the keratin overlying the papillae. Normally, the amount of keratin produced equals the amount of keratin that is swallowed with food. The balance is disrupted when there is an increase in keratin production or a decrease in swallowed keratin. The keratin or dead cells and the papillae grow and lengthen rather than being shed, creating hairlike projections that are subjected to entrapment and staining by food, liquids, tobacco, bacteria, and yeast.
Megaloglossia is, on rare occasions, an isolated congenital anomaly. An acute form is caused by septic infections and by giant urticaria. The chronic form is a result of lymphangioma or hemangioma, or a secondary effect of Down syndrome, acromegaly, or myxedema. (It can also be produced by tumors, syphilis, and tuberculosis.) In myxedema, the tongue enlarges, resulting in thick speech and difficulty with mastication and swallowing. The margins are typically lobulated from the pressure or confinement against the teeth.
Luetic glossitis has been variously called bald or glazed luetic tongue, sclerous or interstitial glossitis, or lobulated syphilitic tongue. The clinical appearance depends on the extent of gummatous destruction, which may be superficial or deep, causing an endarteritis with a smooth, atrophic surface. Hyperkeratosis may also be evident. On palpation various degrees of fibrous induration are detected in the relaxed tongue. The surface is thrown into ridges, grooves, and lobulations, with a pattern of scars that may assume a leukoplakic appearance. The induration and scarring are a direct result of the gummas. The smooth, depapillated, “varnished” surface is, strictly speaking, an atrophic symptom seen in advanced forms of anemias, vitamin B deficiency, celiac sprue, Plummer Vinson syndrome, and prolonged cachectic states.
An amyloid tongue is usually a part of a generalized amyloidosis. Only occasionally are isolated amyloid deposits found in the base of the tongue without a generalized disease. The tongue, as illustrated here, has been heavily infiltrated, together with the liver, spleen, and other mesodermal organs, in a generalized secondary amyloidosis resulting from a multiple myeloma. Amyloid deposition causes a hyaline swelling of connective tissue fibers, with accumulation of waxlike material and obliteration of vessels through thickening of their walls. Clinically, the tongue is enlarged and has mottled dark-purple areas with translucent matter. Furrows and lobules cover the denuded dorsum. The diagnosis is easily ascertained by a biopsy specimen, which shows the typical brown color when exposed to Lugol solution and turns blue when sulfuric acid is added. Lugol solution will also elicit the diagnostic reaction if it is introduced into a small lingual incision in situ.