Introduction
Pediatric lymphadenopathy has a broad differential, one of which is
progressive transformation of germinal centers (PTGC). PTGC is
characterized histologically by the expansion of mantle zone
lymphocytes, follicular dendritic cells, and T-cell lymphocytes into
germinal centers, resulting in germinal center enlargement and
disruption of architectural differentiation in the lymph node
(LN).1 The expansion of LN follicles causes clinically
apparent LN enlargement. Affected LN may contain epithelioid histiocytes
and other cells consistent with infection or granulomatous
reactions;1 however, patients with PTGC may have no
symptoms other than LN enlargement.2 Nodes affected by
PTGC can recur after excisional surgeries. Interestingly, PTGC can
precede, occur synchronously, or occur after the diagnosis of
lymphomas,3-5 although the association between
lymphomas and PTGC remains unclear. While PTGC is a rare diagnosis
overall, it has been better described in adults and shows a predominance
among young adult males.4 Given that literature
describing the clinical and diagnostic features of PTGC in pediatric
patients remains limited to small case series,2,6-8 we
reviewed pediatric cases of PTGC at our institution across 20 years to
add to the data surrounding this diagnostic mystery.