ABSTRACT
Missense and protein truncating TSC2 mutations associated with LOH were subsequently described in the lung and kidney lesions of patients with S-LAM.25 Adjacent normal lung tissue and circulating blood cells were free from mutations, and within a given patient the mutations in the lung and kidney were identical, consistent with origin from a common precursor.24,25 These data suggested that LAM may arise by benign metastasis of LAM cells from another site; perhaps a kidney tumor, axial lymph nodes, or a progenitor cell in the bone marrow.40 Reports of recurrence of LAM in the donor lung of LAM patients who had undergone lung transplantation are also consistent with the metastatic theory,41-44
including two in which the lesional cells were proven to
Figure 18B.1 Comparison of the phenotype of tuberin-deficient and wildtype Drosophila eyes. Random gene inactivation was followed by characterization of eye phenotypes. Enlarged eyes cells in tuberin-deficient flies (b) compared to wildtype flies (a) were discovered. Phase microscopy revealed differences between normal pigmented wildtype eye cells (c, upper left), compared to enlarged, nonpigmented cells in tuberin-deficient flies (c, lower right). Bristles (d) arising from cells at the anterior edge of the wing were larger and less pigmented in those containing tuberin mutations (gig). Photomicrographs of cells in the wing revealed enlargement in those containing the tuberin (gig) mutant
originate from recipient tissues by molecular techniques.
