Leptomeningeal dissemination from an ethmoidal sinus adenocarcinoma in cerebrospinal fluid cytology.

A 68-year-old man was admitted to hospital because of the presence of neurological symptoms (mainly frontal headache and confusion) and signs of meningeal irritation. According to his medical records, he was an ex-smoker (2 years ago) and he suffered from perennial rhinitis. The patient did not report labor precedents in relation to the exposure to wood, leather or others. After physical examination, a lumbar puncture, computed tomography (CT) scans, and later, a trans-nasal endoscopic biopsy were performed. The patient’s condition worsened progressively and he finally died 10 days after his admittance to hospital. The autopsy could be performed. The Papanicolaou-stained cytospin smears of the cerebrospinal fluid (CSF) showed tumor cells with enlarged nuclei and abundant vacuolated cytoplasms (Figure 1A). Numerous mononuclear cells and basophilic amorphous material were in the background. The vacuolated cells were also positive for the PAS stain. CT scans revealed a sinonasal tumor of an apparent ethmoidal origin (Figure 1B). The trans-nasal biopsy of the sinonasal tumor showed an intestinal-type adenocarcinoma (mucinous growth pattern) with single signet-ring-type cells within a mucoid background under a benign respiratory epithelium (see the inset in Figure 1A). A mucicarmin stain exhibited strong cytoplasmic positivity, and the tumor cells stained positive for cytokeratin 7, cytokeratin 20 and CDX2. Based on the clinical setting and this pattern of immunostaining, a diagnosis of primary sinonasal adenocarcinoma was favored over one of metastatic adenocarcinoma from the gastrointestinal tract or from any other site. Autopsy confirmed the ethmoid sinus as the primary site of the tumor, showing an infiltrating growing pattern with abundant mucosubstance.