AL amyloidosis and transthyretin (ATTR) amyloidosis are the most frequent forms of systemic amyloidosis diagnosed in the United States. Macroglossia is considered to be a pathognomonic feature of AL amyloidosis. We report on two cases of systemic amyloidosis with macroglossia that defied routine clinical diagnosis, in which the deposits were typed as ATTR in one case and AL in the other using immunoelectron microscopy. These cases highlight: (1) the difficulty of typing amyloidosis on clinical criteria alone; (2) the utility of immunoelectron microscopy and (3) that macroglossia, while occurring much more frequently in AL, can also accompany ATTR amyloidosis.