More recently, FL patients have been treated with other regimens including: 1) rituximab combined with the chemotherapeutic alkylating agent bendamustine; 2) rituximab combined with the chemotherapeutic agent fludarabine and the inhibitor of Type II topoisomerase, mitoxantrone; and 3) rituximab combined with another immunotherapeutic agent such as galiximab, epratuzumab (monoclonal antibodies directed respectively against the CD80 or CD22 cell surface proteins on immune cells including B cells), or the immunomodulating medication, lenalidomide. While it is too soon to judge the long-term results of the latter regimens, the regimens have shown similar results when analyzed based on poor treatment responses (~10-20% poor responses). Bendamustine with rituximab may be preferable to R-CHOP or R-CVP for treating low-grade (i.e. Grades 1, 2, and possibly 3A) FL; R-CHOP may be preferred in FL that has high-risk characteristics (e.g. high levels of Beta-2 macroglobulin or bone marrow involvement). The combination of lenalidomide with rituximab has shown good potential in treating indolent cases of FL.Studies indicate that maintenance therapy with rituximab following successful induction therapy prolongs progression-free survival; for example one study found progression-free survival after 6 years of treatment was 59.2% in patients treated with rituximab maintenance and 42.7% without this maintenance; however, overall survival at 6 years was similar in the two groups, 87.4% and 88.7%, respectively. Another study found that prolonged maintenance with rituximab did not have any benefits over an eight-month maintenance period.
The two can be differentiated as follows: a hamartoma is an excess of normal tissue in a normal situation (e.g., a birthmark on the skin), while a choristoma is an excess of tissue in an abnormal situation (e.g., pancreatic tissue in the duodenum). The term hamartoma is from the Greek ἁμαρτία, hamartia ("error"), and was introduced by D.P.G. Albrecht in 1904. Causes
Hamartomas result from an abnormal formation of normal tissue, although the underlying reasons for the abnormality are not fully understood. They grow along with, and at the same rate as, the organ from whose tissue they are made, and, unlike cancerous tumors, only rarely invade or compress surrounding structures significantly. Diagnosis
Types
Lung
About 5–8% of all solitary lung nodules and about 75% of all benign lung tumors, are hamartomas. They almost always arise from connective tissue and are generally formed of cartilage, connective tissue, and fat cells, although they may include many other types of cells. The great majority of them form in the connective tissue on the outside of the lungs, although about 10% form deep in the linings of the bronchi. They can be worrisome, especially if situated deep in the lung, as it is sometimes difficult to make the important distinction between a hamartoma and a lung malignancy. An X-ray will often not provide a definitive diagnosis, and even a CT scan may be insufficient if the hamartoma lacks the typical cartilage and fat cells. Lung hamartomas may have popcorn-like calcifications on chest xray or computed tomography (CT scan).