Placental Tuberculosis: A Microscopic Portrait of a Rare Diagnosis

Placental tuberculosis (TB) is a rare manifestation of maternal TB with significant implications in terms of fetal and neonatal outcomes. Placental involvement usually occurs by hematogenous seeding of bacilli from an infected mother, and may be seen even in the absence of active maternal pulmonary disease. We present an incidental case of placental TB in a 35-yr-old woman at 37+2 wk gestation, whose routine placental microscopy revealed necrotizing epithelioid cell granulomas, and Ziehl-Neelsen staining demonstrated acid-fast bacilli. The Xpert MTB/RIF Ultra assay performed on the placental tissue was positive for Mycobacterium tuberculosis. Following this diagnosis, the mother underwent a thorough evaluation for pulmonary tuberculosis, and she was started on a standard first-line antitubercular regimen (ATT). The neonate, who had BCG vaccination at birth, was also evaluated and was started on isoniazid preventive therapy (IPT) for 6 mo. Both mother and infant were asymptomatic at 3 mo of follow-up.