A Schwannoma is a benign encapsulated neoplasm derived from schwann cells of nerve sheath. The exact incidence of schwannomas is unknown, but they are rare. Schwannomas are found in all age groups but are more common in the first four decades and affect both sexes equally. They may occur in association with neurofibromatosis or arise sporadically. The microscopic appearance of schwannoma is distinctive [1
], with two recognisable patterns. Antoni A areas are composed of compact spindle cells often arranged in palisades or in an organoid arrangement (verocay bodies). Antoni B areas consist of tumour cells suspended in a myxomatous matrix that may appear microcystic. Several variants of schwannomas based on appearances have been observed, including cellular, glandular, epithelioid and ancient types and exhibit benign progression. Cellular schwannomas are almost exclusively composed of antoni A areas but lack verocay bodies. The epithelioid and glandular variants compose of epithelioid areas and glandular component respectively to acquire their descriptive names.
Ancient schwannomas show bizarre hyperchromatic nuclei without mitoses. To the inexperienced these features can lead to an erroneous diagnosis of malignancy, although the very low mitotic activity should allow these tumours to be distinguished from malignant nerve sheath tumours.
A literature review showed that ancient schwannomas are rare, most cases occur in the head and neck region [2
]. Other less common sites include the extremities, mediastinum, thorax [3
], retroperitoneum [4
], pancreas [5
], pelvis [6
] and scrotum [7
]. We could not find references pertaining to ancient variant in the hypopharyngeal region.
Ancient schwannomas involving hypopharynx pose a difficult diagnostic challenge to ENT surgeons. Radiological findings are often non-specific [8
]. Ultrasonography can differentiate between solid and cystic tumours. CT scan can be helpful in determining the size, location, local involvement and distant spread. Magnetic resonance imaging (MRI) provides similar useful information as CT but yields better visualization of the tumour [7
]. Fine needle aspiration cytology is difficult in this area, if done is not often helpful because the tissue architectural information required is not obtainable from cytological specimen. The only gold standard diagnostic investigation is histology of either biopsy or excised specimen.
Surgical excision has remained the mainstay of treatment. Although benign, large and incompletely excised lesions are capable of recurrence; malignant change is extremely rare [3