It is well documented that nevus cells can be found within the fibrous capsule and trabeculae of lymph nodes; however, it is less well known that nevus cells can also be found in the lymph node parenchyma. We report the findings in 13 cases of nevus cell aggregates located within the cortical and/or medullary parenchyma of lymph nodes. Seven of the 13 @entity1 had a primary diagnosis of @entity320 , three had no known @entity5 , one had @entity0 , one had @entity189 of the skin, and one had @entity957 . Of the seven @entity1 with @entity320 , four had axillary lymph node dissections and three had inguinal lymph node dissections. The @entity1 with @entity189 had @entity189 in 14 of 20 lymph nodes that had been dissected; one of them also had intraparenchymal nevus cells. The @entity1 with @entity957 had an intraparenchymal nevus cell aggregate in one of the 21 dissected lymph nodes; all 21 were negative for @entity189 . Nests of intraparenchymal nevus cells ranged from clusters of only a few cells up to 2.1-mm aggregates. No mitotic figures, prominent nucleoli, or @entity7453 were detected in any of the melanocytic aggregates. The melanocytic cells of the nevus cell aggregates expressed @entity2281 protein and/or @entity16524 but not @entity9857 protein (HMB-45). Less than 1% of the nevus cells expressed Ki-67. The purpose of this study was to draw attention to the finding of nevus cells in the parenchyma of lymph nodes and to alert pathologists to this as a potential diagnostic pitfall, especially in @entity1 with concurrent @entity320 or @entity189 . Awareness that nevus cells can be present in nodal parenchyma, analysis of their morphologic features (including comparison with any previous or existing @entity320 or @entity189 ), and immunophenotyping will help pathologists to establish the correct diagnosis in most instances.

Intraparenchymal nevus cell aggregates in lymph nodes: a possible diagnostic pitfall with XXXX .

@entity1 :: ('9606', 'Species') :: ['patients', 'patient'] @entity9857 :: ('6490', 'Gene') :: ['gp100'] @entity0 :: ('MESH:D001943', 'Disease') :: ['breast carcinoma'] @entity5 :: ('MESH:D009369', 'Disease') :: ['malignancy'] @entity957 :: ('MESH:D002294', 'Disease') :: ['squamous cell carcinoma of the tonsil'] @entity189 :: ('MESH:D002277', 'Disease') :: ['metastatic carcinoma', 'carcinoma', 'adnexal carcinoma'] @entity7453 :: ('MESH:D008207', 'Disease') :: ['lymphatic-vascular invasion'] @entity16524 :: ('388015', 'Gene') :: ['MART-1'] @entity2281 :: ('6271', 'Gene') :: ['S-100'] @entity320 :: ('MESH:D008545', 'Disease') :: ['melanoma']
@entity320 :: (MESH:D008545,Disease) :: ['malignant melanoma and carcinoma']
