Its treatment duration is 48 weeks, unlike oral antivirals which require indefinite treatment for most patients (minimum one year). PEG IFN is not effective in patients with high levels of viral activity and cannot be used in immunosuppressed patients or those with cirrhosis. Lamivudine was the first approved oral nucleoside analogue. While effective and potent, lamivudine has been replaced by newer, more potent treatments in the Western world and is no longer recommended as first-line treatment. It is still used in areas where newer agents either have not been approved or are too costly. Generally, the course of treatment is a minimum of one year with a minimum of six additional months of "consolidation therapy." Based on viral response, longer therapy may be required, and certain patients require indefinite long-term therapy. Due to a less robust response in Asian patients, consolidation therapy is recommended to be extended to at least a year. All patients should be monitored for viral reactivation, which if identified, requires restarting treatment. Lamivudine is generally safe and well tolerated. Many patients develop resistance, which is correlated with longer treatment duration. If this occurs, an additional antiviral is added. Lamivudine as a single treatment is contraindicated in patients coinfected with HIV, as resistance develops rapidly, but it can be used as part of a multidrug regimen. Adefovir dipivoxil, a nucleotide analogue, has been used to supplement lamivudine in patients who develop resistance, but is no longer recommended as first-line therapy.
Histiocytic sarcoma is a tumor derived from histiocytes. The tumor is often positive for CD163 and can appear in the thyroid. However, in some cases it can also appear in the brain. References


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