Lyme disease mimicking central nervous system lymphoma.

A 33-year-old male presented with a complaint of intermittently blurred vision and right facial weakness. MRI of the brain and orbits revealed numerous cranial nerve abnormalities. There were no focal brain or spinal cord lesions. Cerebral spinal fluid flow cytometry revealed a monoclonal population of B-lymphoid cells. No other evidence of disease was found. Serum Lyme antibody was reported to be IgM positive. Therapy with ceftriaxone, was followed by improvement in his symptoms. Although flow cytometry is a useful tool in distinguishing malignancy from inflammatory disorders it does not always establish the diagnosis of malignancy by itself.

Solitary fibrous tumor of nasal cavity in patient with long-standing history of cocaine inhalation.

We report a solitary fibrous tumor in the nasal cavity of a 48-year-old woman who presented with a history of bilateral nasal obstruction and long-standing cocaine inhalation. Physical examination revealed a large mass involving the right nasal cavity and extending into the posterior aspect of the left nasal cavity. The computed tomography scan showed opacification of airways. During surgery, the mass was found to involve the entire nasal cavity, with extension to the right maxillary sinus, posterior nasal airways, and left nasal cavity. The mass was completely excised. Pathologic examination revealed a polypoid mass 3.7 x 3.0 x 1.2 cm. This tumor was composed of spindle cells that were cytologically bland in a background of ropey and nodular collagen, giving a "patternless" pattern. Immunohistochemically, the neoplastic cells stained for CD34 and vimentin but not for S100 protein, keratin, desmin, HMB-45, and c-Kit. This immunohistochemical pattern confirmed the diagnosis of solitary fibrous tumor. Although solitary fibrous tumors are usually found in the pleura, they can occur in various other locations, such as the orbit, nasal cavity, paranasal sinuses, mediastinum, breast, vagina, meninges, and soft tissues. This case is of interest because the tumor occurred in a patient with prolonged cocaine inhalation. Such an association has not been previously described. The exact causal relationship between cocaine inhalation and the tumor is not known.