ABSTRACT. Spinal paragonimiasis is a rare form of ectopic infestation caused by Paragonimus westermani. We report a case of pathologically proven intradural paragonimiasis associated with concurrent intracranial involvement. MRI revealed multiple well-defined intradural masses that were markedly hypointense on T 2 weighted images and hypointense with a peripheral hyperintense rim on T 1 weighted images. Contrast-enhanced T 1 weighted images showed slight peripheral rim enhancement. Paragonimiasis caused by Paragonimus westermani and related species occurs in Asia, Africa and South America, but most commonly in Korea, Japan and China [1,2]. Human infestation by P.westermani occurs from ingestion of raw or incompletely cooked freshwater crabs or crayfish infected with the encysted larvae of the fluke. The ingested juvenile worms (metacercariae) of P.westermani penetrate the intestinal wall, the peritoneum and the diaphragm, finally invading the pleural cavity and the lung where they become mature adult worms [3,4].The complicated biology of P.westermani is the reason why paragonimiasis can occur throughout the human body [1]. Extrapulmonary paragonimiasis has been reported in several sites, including the brain, spinal cord, abdomen, appendix, inguinal region, subcutaneous tissue, eye, thigh and genitals [5].The central nervous system (CNS) is known to be the most common site of extrapulmonary paragonimiasis. The rate of cerebral paragonimiasis is approximately 0.8% of all active paragonimiasis [1]. However, spinal paragonimiasis is very rare compared with the incidence of cerebral paragonimiasis (less than 10% of cerebral paragonimiasis) [6].To the best of our knowledge, there has been no previous report describing the imaging features of spinal paragonimiasis in the English language literature. In this case report, we described imaging features of a case of pathologically proven spinal paragonimiasis with emphasis on the MRI findings.
Case reportA 44-year-old female presented with severe neurogenic claudication owing to spondylolisthesis at the level of L4-L5. Neurological examination revealed right side homonymous hemianopsia and monoparesis in the right arm. Laboratory data including peripheral blood examination and blood chemistry revealed normal ranges and stool examination for parasitic eggs was negative. The level of Paragonimus specific antibody (IgG) in cerebrospinal fluid (CSF) was borderline negative (0.224; normal range, 0-0.28) on enzyme-linked immunosorbent assay (ELISA).MRI of the lumber spine revealed multiple well-defined intradural masses. They appeared marked hypointense on T 2 weighted images (Figures 1a,b). T 1 weighted images showed masses to be hypointense relative to CSF with a peripheral hyperintense rim (Figure 1c). Post-contrast T 1 weighted images showed slight peripheral rim enhancement (Figure 1d). CT scan showed multiple calcified nodules in the lumbar intradural space (Figure 1e). MRI of the brain revealed multiple well-defined nodular or cystic masses in the left occipital and pari...