Reply to Linghu

We read with great interest the letter by Yang and Linghu, which discussed the proof of diagnosis for tuberculosis and sarcoidosis in our study of patients in whom routine diagnostic procedures had failed. For the diagnosis of tuberculosis we chose an unconventional “gold standard,” which was drawn from the UK National Institute for Health and Clinical excellence (NICE) guidelines, to confirm or refute the diagnosis of tuberculosis by the composite end-point of culture, radiographic appearances (i. e. repeated computed tomography scan), repeated endoscopic ultrasonography-guided fine-needle aspiration where thought to be necessary, and clinical deterioration as determined over a 12-month follow-up period [1].

The diagnosis of sarcoidosis was made by the combination of cytology with positive epithelioid cell granuloma, negative bacteriology, and 12-month clinical follow-up. There were three results where sarcoidosis was mistaken for tuberculosis, as the bacteriology was negative. These findings highlight that the diagnosis of sarcoidosis cannot be made on cytological/histological demonstration of non-caseating granulomas alone, but needs a compatible clinical picture and exclusion of other diseases capable of producing a similar histological or clinical appearance [2]. Unfortunately, in many countries the Kveim test is no longer used for the diagnosis of sarcoidosis; therefore, we did not use it in our study, which was performed in the UK.

• References

• 1 Fritscher-Ravens A, Ghanbari A, Topalidis T et al. Granulomatous mediastinal adenopathy: can endoscopic ultrasound-guided fine-needle aspiration differentiate between tuberculosis and sarcoidosis?. Endoscopy 2011; 43: 955-961
• 2 Costabel U, Hunninghake GW. Sarcoidosis Statement Committee. ATS/ERS/WASOG statement on sarcoidosis. Eur Respir J 1999; 14: 735-737