Short report: A calcified Taenia solium granuloma associated with recurrent perilesional edema causing refractory seizures: histopathological features

Abstract

We describe the first detailed histological description of an excised calcified Taenia solium granuloma from a patient who developed recurrent seizures associated with perilesional edema surrounding a calcified cysticercus (PEC). The capsule, around a degenerated cysticercus, contained marked mononuclear infiltrates that extended to adjacent brain, which showed marked astrocytosis, microgliosis, and inflammatory perivascular infiltrates. The presence of large numbers of mononuclear cells supports an inflammatory cause of PEC. Immunosuppression or anti-inflammatory measures may be able to treat and prevent PEC and recurrent seizures.

Figures

Figure 1.

Serial MRI fluid-attenuated inversion recovery (FLAIR) imaging of the patient showing change in perilesional edema over time. (A) CT scan of the patient at presentation (August 11, 2006) to the treating hospital. (B) MRI on August 8, 2006 at presentation. (C) MRI on August 11, 2006 at presentation. (D) MRI on September 5, 2006. (E) MRI on March 1, 2007. (F) MRI on May 11, 2007. A–C show a central area of calcification with surrounding edema. The edema around the lesion changed over time depending on the clinical state.

Figure 2.

(A and B) Photograph of two histological sections of the excised lesion. P = degenerated parasite; I = inflammation; AC = amorphous material with calcification; C = collagen; CC = calcareous corpuscles; B = brain. The arrowed line shows the extent of the capsule. The lesion is roughly organized into concentric layers (A) consisting of centrally located eosinophilic material containing thick, bright ribbons of membranous-like tissue, which is most likely a degenerated cysticercus. A granular calcified layer, often adjacent to the host capsule, partially surrounds the core. A tissue section from another region (B) contains a dense mass of concentrated calcified calcareous corpuscles in the core, which are characteristic of cestodes. The degenerated parasite mass is surrounded by a dense collagenous wall making up the host capsule. A mononuclear infiltrate consisting primarily of lymphocytes, macrophages, and plasma cells courses through the capsule but is particularly dense adjacent to the brain. Eosinophilis are present in relatively small numbers and do not predominate. The surrounding brain is markedly abnormal with reactive gliosis, which is denoted by glial fibrillary acid protein immunostaining (not shown), CD3-positive T cells (Figure 4C), and histiocytosis and microgliosis by KP1 reactivity (Figure 4D). There is extensive inflammatory perivascular cuffing in adjacent brain tissue.

Figure 3.

Higher power view of calcareous corpuscles, which are characteristic of cestodes. The very dense and large mass likely is a cause of calcification. The arrow points to one of many calcareous corpuscles. This figure appears in color at www.ajtmh.org.

Figure 4.

(A) Higher power view of degenerated parasite and amorphous calcified material. (B) Higher power view of the capsule wall with mononuclear infiltrate. (C) CD3-positive T cells. (D) KP1-positive macrophages and microglia. This figure appears in color at www.ajtmh.org.