Whereas the hexagonal Golomb graph and the regular hexagonal tiling generate chromatic numbers of 4 and 7, respectively, a chromatic coloring of 5 can be attained under a more complicated graph where multiple four-coloring Moser spindles are linked so that no monochromatic triples exist in any coloring of the overall graph, as that would generate an equilateral arrangement that tends toward a purely hexagonal structure. The plane contains a total of five Bravais lattices, or arrays of points defined by discrete translation operations: hexagonal, oblique, rectangular, centered rectangular, and square lattices. The plane can also be tiled monohedrally with convex pentagons in fifteen different ways, three of which have Laves tilings as special cases.Five points are needed to determine a conic section, in the same way that two points are needed to determine a line.
proposed that local immunodeficiency as a result of lymphedema results in a "immunologically privileged site" in which the sarcoma is able to develop. Diagnosis
Treatment
The most successful treatment for lymphangiosarcoma is amputation of the affected limb if possible. Chemotherapy may be administered if there is evidence or suspicion of metastatic disease. Evidence supporting the effectiveness of chemotherapy is, in many cases, unclear due to a wide variety of prognostic factors and small sample size. However, there is some evidence to suggest that drugs such as paclitaxel, doxorubicin, ifosfamide, and gemcitabine exhibit antitumor activity. See also
Angiosarcoma
Hemangiosarcoma
Lymphangioma
Sarcoma
Stewart–Treves syndrome

References


== External links ==