'Pomegranate' Spleen in Disseminated Tuberculosis

Abstract

A 33-year-old HIV-infected female patient who had died at Maputo Central Hospital, Maputo, Mozambique, after less than 24 hours of hospitalization, underwent a full postmortem examination to ascertain the cause of death. Antemortem chest radiography showed hyperinflated lungs, with scattered bilateral lesions compatible with a diagnosis of miliary tuberculosis (TB), which was (after postmortem examination) determined to be the final cause of death. The spleen was firm at touch, with multiple yellowish nodules randomly distributed throughout the surface of the spleen capsule. Gross examination of the spleen sections showed that the nodules and plaques massively infiltrated the spleen parenchyma, which showed a characteristic pomegranate aspect (Figures 1A and 1B). The histological sections confirmed the presence of caseous granulomas (Figure 1C). The presence of Mycobacterium tuberculosis bacilli in the spleen samples was confirmed by a specific in-house real-time polymerase chain reaction (1) and by Xpert MTB/RIF assay. The main differential diagnosis of this rarely reported macroscopic finding would be splenic neoplasms, infarcts, abscesses, and granulomas of varying etiology; and, in endemic areas, melioidosis (2). Although scarce data exist in the literature, the frequency of the underlying disease causing this macroscopic finding varies significantly depending on the geographical area. Infectious diseases account for a significant proportion of these lesions in developing countries (3), whereas in Western countries the predominant causes are neoplasms, mainly malignant lymphomas or metastatic carcinomas (4). Knowledge of the macroscopic aspect of splenic TB, which at cross-section resembles the inside of a pomegranate, could guide pathologists to rule in disseminated TB diagnosis on the basis of gross pathology, especially in high-burden TB/HIV countries.