[Adenoid cystic carcinoma presenting as cavernous sinus syndrome: a clinico-pathological study of two cases].

Adenoid cystic carcinoma (ACC), usually arising in the major and minor salivary glands, is well known to otolaryngologists, but is rarely encountered by neurologists or neurosurgeons. We report two ACC patients who presented initially with cavernous sinus syndrome and in whom CT did not demonstrate apparent abnormalities. Case 1 is a 48-year-old man who first developed right cavernous sinus syndrome. The patient came to our hospital four years later. At this time, the only abnormality found on CT was the clouded sphenoid sinus on the left, which was interpreted as sinusitis. Two years later, the repeat CT revealed the enhancing lesions in the area of bilateral cavernous sinuses with bony destruction. The nasolaryngological exploration of the left sphenoid sinus made the diagnosis of ACC. Case 2 is a 43-year-old man who developed unilateral cavernous sinus syndrome over three months. No radiological abnormality was apparent to the neurologist and neurosurgeons, however, the otolaryngologist detected a nasopharyngeal mass diagnosed as ACC. Histological examinations of the biopsy specimen from both cases revealed mixed cribriform, tubular, and solid patterns characteristic of ACC. Electron microscopic study in Case 1 demonstrated microvilli-containing epithelial tumor cells forming true glandular lumens. In these cystic spaces there were cellular debris and crystalloids consisting of hexagonally-arranged tubules with a diameter of 25 nm. Although thick basement membrane was found in the basal portion of the tumor cells facing the connective tissue, there was no so-called pseudocysts lined by replicated basal lamina. It is possible that the specimen examined electron microscopically is limited to a particular epithelial region.(ABSTRACT TRUNCATED AT 250 WORDS)