Critical role of molecular test in early diagnosis of gastric tuberculosis: a rare case report and review of literature

BACKGROUD: Early diagnosis of gastric tuberculosis is often challenging because the disease is very rare and its clinical manifestation is nonspecific and misleading. To raise the awareness and emphasize early diagnosis of gastric tuberculosis, we present a case of gastric tuberculosis secondary to pleural and pulmonary tuberculosis. CASE PRESENTATION: A 26-year-old woman complained gastric pain for 1 month but showed no other symptoms, who had no previous exposure to tuberculosis.Gastric stromal tumor was originally suspected. However, the pathology of her gastroscopic biopsy of the gastric lesion showed granulomatous lesions and caseating necrosis. Gene sequencing of the biopsy specimen identified deoxyribonucleic acid fragment of Mycobacterium tuberculosis. Chest computed tomography scan revealed nodular shadows in the lesser curvature soft tissue of the stomach, patchy densities and calcified nodular shadows in the upper right lung, bilateral pleural thickening, and calcified pleural nodules. Thus, the diagnosis was gastric tuberculosis secondary to pulmonary and pleural tuberculosis. The patient was hospitalized and treated with the antituberculosis therapy for 1 week. After discharged from the hospital, the patient continued routine antituberculosis therapy for 18 months and was follow-up was normal.Literature search found 22 cases of gastric tuberculosis reported from 2000 to 2016. Review of the 22 cases suggested that polymerase chain reaction has been increasingly used in the recent years in addition to the conventional histopathological and bacteriological approaches. CONCLUSION: Clinical presentation of gastric tuberculosis is not specific.When granuloma or caseation is detected on biopsy in patients who are suspected of having gastric malignancy or acid peptic diseases, polymerase chain reaction for Mycobacterium tuberculosis could be used as an available and sensitive diagnostic test in addition to pathology, acid-fast bacilli smear staining and culture.