Classic follicular dendritic reticulum cell tumor of the lymph node developing in a patient with a previous inflammatory pseudotumor-like proliferation.

Inflammatory pseudotumor (IPT) and follicular dendritic reticulum cell tumor (FDRCT) are rare entities of the lymph node characterized by spindle-cell proliferation. We report a case of a 31-year-old woman, who was admitted for biopsy of a lymph node in the left submandibular area. The microscopic examination revealed a proliferation of spindle cells, partially replacing the normal lymph node architecture, suggestive of an IPT. The preserved peripheral portion showed follicular hyperplasia with Castleman-like appearance. Six years later she presented with a new enlargement in the same submandibular area. The nodule was removed, and a diagnosis of a classic FDRCT of the lymph node was made. The present case is remarkable, and clinicopathological data show that IPT-like proliferations could be in some case an early presentation of FDRCT.