[The appearance of "lambda" and "panda" sign on Ga-67 scintigraphy in sarcoidosis]

The lesions of sarcoidosis generally show relatively high Ga-67 uptake and the usefulness of scintigraphy using this agent in the evaluation of lesion activity is well known. In this report, we assessed characteristic uptake of Ga-67 in intrathoracic lymphnodes, the shape of which resembled the Greek letter Lambda (Lambda sign) and a symmetrical accumulation in bilateral lacrimal and salivary glands which resembled a Panda face (Panda sign) in patients with sarcoidosis. Our review of Ga-67 scans obtained from 15 patients with sarcoidosis and 1,779 patients with other disorders during the past 3 years revealed that the simultaneous presence of both Lambda and Panda signs was specific to patients with sarcoidosis and was not found in patients with various other disorders, although one of these signs might be observed in patients without sarcoidosis. When Lambda-like sign was observed, chest radiogram or CT was necessary for the differential diagnosis of sarcoidosis. Panda sign was observed frequently among patients who had previously received irradiation of the neck. Our results confirmed that sarcoidosis must be suspected when both Lambda and Panda signs were observed.