Severe erosive stomatitis: association with immunological diseases?

We present 2 cases of severe erosive stomatitis. The first case involves the rare association of an extensive, erosive lichen planus with a Castleman's tumor. The second case involves the association of lichen planus pemphigoides with severe, obstructive lung disease (bronchiolitis obliterans). We believe that in both cases the conjunction of these conditions is not fortuitous but perhaps due to an underlying immune dysfunction. With patients presenting a severe, therapy-resistant, erosive stomatitis, one should be alerted to the possibility of immunological diseases and/or tumors.