Toxoplasma cyst detection in Piringer-Kuchinka lymphadenitis. Report of two cases and literature review.

The diagnosis of acute toxoplasmic lymphadenitis is traditionally based on the combination of lymph node excisional biopsy with specific tests. The classic triad (marked follicular hyperplasia, small irregular clusters of epithelioid histiocytes in germinal centers, and sinusoidal distension by monocytoid B lymphocytes) is considered diagnostic of the so-called Piringer-Kuchinka lymphadenitis. Toxoplasma gondii organisms have been exceptionally disclosed in such histopathological setting, establishing the diagnosis of toxoplasmic lymphadenitis. Two cases of Piringer-Kuchinka lymphadenitis with toxoplasma cyst demonstration are reported, along with a complete review of the literature.