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NASAL SCHWANNOMA

CHARU J MODI*, NK BEHL**, DS GREWAL+
*Associate Professor; **Professor, Department of Pathology; +Professor, Department of ENT, TN Medical College and BYL Nair Ch. Hospital, Mumbai - 8.

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Schwannomas (Neurilemmomas) are rare in the nasal cavity. Histologically they differ from schwannomas at other sites by absence of encapsulation which when associated with hypercellularity can be mistaken for malignancy. We report a case of nasal schwannoma in a 24 year old female patient.

CASE REPORT

A 24 year old female patient presented with c/o epistaxis for six months, increased for last two months. C/o blocked nose, rhinitis and headache for one month. O/e presence of mass and absence of air blast in the right nostril. The mass showed bleeding on touch. CT scan also revealed the nasal mass, which had increased vascularity. Excision of the mass was done.

Histopathology showed respiratory epithelium along with the tumour tissue (Fig. 1). The tumour consisted of antoni A and antoni B areas (Fig. 2). Antoni A areas were cellular and were composed of spindle cells arranged in palisading pattern. Antoni B areas consisted of cells separated by oedematous stroma. Very occasional mitosis was observed. Diagnosis of schwannoma was given.

Fig 1: Respiratory epithelium along with the schwannoma (HE 40).

Fig 2 : Schwannoma showing hypocellular and hypercellular areas with nuclear palisading (HE 100)

DISCUSSION

Schwannomas (Neurilemmoma), which arise from the schwann cells of the nerve sheath, occur rarely in the sino-nasal tract. [1] Schwannomas arising from the nasal cavity and paranasal sinuses account for less than 4% of the benign peripheral nerve sheath tumours of the head and neck region. [2] Intracranial extension has been reported. [3,4] Malignant schwannomas at this site are very rare. [5]

Presenting clinical symptoms include nasal obstruction, epistaxis, rhinorrhoea, anosmia and headache. [2] Rarely it presents as a nasal tip deformity. [6]

Histology of the nasal schwannomas differs from those at the other sites, by its lack of encapsulation which when combined with hypercellularity can raise a suspicion of malignancy. [2] However in spite of these features nasal schwannomas neither show local recurrence nor postoperative metastasis. [2]

REFERENCES

1.Srinivasan V, Deans JA, Nicol A. Sphenoid sinus schwannoma treated by endoscopic excision. J Laryngol Otol 1999; 113 : 466-8.

2.Hasegawa SL, Mentzel T, Fletcher CD. Schwannomas of the sinonasal tract and nasopharynx. Mod Pathol 1997; 10 : 777-84.

3.Gatscher S, Love S, Coakham HB. Giant nasal schwannoma with intracranial extension. J Neurosurg 1998; 89 : 161.

4.Hanada T, Fukuiwa T, Matsuzaki T, et al. A rare case of nasal schwannoma with intracranial extension. Rhinology 1997; 35 : 181-3.

5.Supiyaphun P, Snidvongs K, Shuangshoti S, et al. Malignant transformation in a benign encapsulated schwannoma of retropharyngeal space. Med Assoc Thai 1997; 80 : 540-6.

6.Mohan D, Krishna A, Rama Krisan V. Schwannoma presenting as a nasal tip deformity. Ann Plastic Surg 1997; 38 : 83-4.

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