Chatzopoulos K, et al. - Immunohistochemistry for succinate dehydrogenase B (SDHB)(clone 21A11AE7) was done on histological sections from six cases of pulmonary chondroma and 33 cases of pulmonary hamartoma in order to examine the utility of SDHB immunohistochemistry in differentiating pulmonary chondromas from hamartomas. In all 33 pulmonary hamartomas, SDHB expression was preserved and in the majority of evaluable chondromas (five of six), it was lost. Four of the five individuals with chondromas exhibiting SDHB loss had definitive Carney triad. Most individuals with pulmonary hamartomas were elderly males with small solitary masses, whereas chondromas frequently exhibited as various masses in young females. Hence, loss of SDHB immunohistochemical expression could be beneficial for distinguishing pulmonary chondromas from hamartomas and possibly recognizing patients with Carney triad.