A rare plexiform neurofibroma of the submandibular gland in a patient with neurofibromatosis is presented. The clinical manifestations of the disease are reviewed. The need for early diagnosis of neurofibroma is emphasized because of malignant tranformation.

Excision of the submandibular gland is a surgical procedure often undertaken. The procedure is the treatment of choice for patients with neoplasm of the submandibular gland and those with non-neoplastic submandibular disorders which are not controlled with conservative medical measures. Extirpation of the submandibular gland may also be undertaken for diagnostic purposes.

This retrospective study of 93 consecutive patients who underwent excision of the submandibular gland in the Department of Otolaryngology, Singapore General Hospital over a five-year period was undertaken to study the indications of surgery, the pathology of the excised submandibular gland and the demographic profile of patients.

Fifty-six (60.2 per cent) patients underwent submandibular gland excision for non-neoplastic salivary gland disease while 37 (39.8 per cent) had neoplastic submandibular gland disorders. The commonest pathology encountered was sialadenitis/sialolithiasis (53.76 per cent) followed by pleomorphic adenoma (33.33 per cent). Fine needle aspiration cytology (FNAC) was a valuable pre-operative investigation with a sensitivity and specificity of 94.7 per cent and 100 per cent respectively for neoplastic diseases. The morbidity rate for this surgery was 4.3 per cent.

The usefulness of fine-needle aspiration cytology (FNAC) in the diagnosis and treatment of submandibular gland lesions is not well known. The 210 FNACs taken from submandibular gland lesions at Turku University Central Hospital between 1984 and 1991 were reviewed. Of these FNACs, 78 samples from primary lesions were confirmed histologically. Within this subset 10 FNACs were taken from benign neoplasms, all of which were correctly classified (sensitivity 100 per cent; specificity 88 percent). Only four of the 14 FNACs from malignant lesions were cytologically considered malignant (sensitivity 29 per cent). On the other hand, four FNACs raised a false suspicion of malignancy (specificity 6 per cent). Out of 54 FNACs from non-neoplastic lesions 43 were correct (sensitivity 80 per cent; specificity 63 per cent). There were 104 patients (123 FNACs), who had not been operated on: the follow-up of these patients shows that in this subset of FNACs there were no false malignant but probably one false benign finding (1 per cent). We conclude that FNAC can offer valuable information about the type of the submandibular gland lesion, but the decision of operative and other treatment should not be based solely on the result of FNAC.

Two cases of submandibular gland swelling are documented. In one patient examination of the excised submandibular gland revealed a dense eosinophilia: the other patient had a peripheral blood eosinophilia. Both patients demonstrated a marked decrease in the swelling of the salivary glands after a course of oral antihistamine. Although allergy has been implicated as a cause of recurrent parotid gland swelling, there are no previous reports of such a phenomenon occurring in the submandibular gland.