Cartilaginous Choristoma of Tonsil

Choristoma is tumor like mass consisting of tissue foreign to the site at which they are located [1]. In head and neck region, choristoma have been reported in pharynx, hypopharynx, oral cavity and middle ear [2,3]. Different types of tissue can occur in oral cavity as choristoma, which can be cartilage, bone, glial tissue, salivary gland and thyroid [3-5].

Here we report a case of chronic tonsillitis with cartilaginous choristoma.

A 30-year-old male presented to Ear, Nose and Throat (ENT) Department with complaint of recurrent episodes of throat pain associated with fever and difficulty in swallowing. On examination, tonsils were enlarged and inflamed with purulent exudates. A clinical diagnosis of chronic tonsillitis was made. Patient underwent bilateral tonsillectomy and the specimen was sent for histopathological examination. Grossly ,the excised tonsil were firm and appeared grey brown in color .Tonsils measured 3×2.5×1.5 cm (right tonsil) and 3×2×1.5cm (left tonsil). Cut section of both the tonsils showed grey white in colour. On microscopic examination, both the tonsils were covered by stratified squamous epithelium with follicular hyperplasia. Left tonsil showed an island of mature cartilage surrounded by lymphoid follicles (Figure 1).

Figure 1: Islands of hyaline cartilage adjacent to follicuar hyperplesia in tonsil (X10).

Cartilaginous choristoma was first described by Berry in 1890 [6]. It occurs in between 10 to 80 years. Natural history of this lesion is not clear but some theories explain as a developmental anomaly in the second pharyngeal arch [7]. Lindholm et al. proposed that chemical or physical changes brought about by chronic inflammation may lead to liberation of osteogenic substances which produce heterotopic proliferation of cartilage [8]. Cartilaginous choristoma of oral cavity is frequently seen in tongue, followed by buccal mucosa and soft palate [9].

Cartilaginous choristoma, which present as chronic tonsillitis with enlargement of tonsil, is extremely rare and very few cases have been reported so far [10]. Cartilaginous choristoma should be distinguished from cartilaginous metaplasia, which usually occurs in the soft tissue beneath ill-fitting dentures [7]. The latter is characterized histologically by diffuse deposits of calcium and scattered cartilaginous cells arranged in various stages of maturation in single or clustered cartilaginous foci [7,11].

In our case, calcification was not seen and the mature cartilage that is not a normal constituent of tonsil was present. Therefore the lesion was considered as choristoma of tonsil.

Simple excision of the lesion with removal of perichondrium is essential since it may have potential to develop new cartilage [1].

Cartilaginous choristoma is a rare entity, which follows a benign course as normal cartilage, elsewhere in the body [12].

Choristoma of tonsil is rare entity, which follows benign course. Though, the natural history is not clear but while evaluating any patient with recurrent tonsillitis, suspicion for this lesion should be made.