Cytomorphology of hyaline-vascular Castleman's disease: a diagnostic challenge
Hyaline-vascular Castleman's disease (CD) is difficult to diagnose on fine needle aspiration and may be mistaken to be a lymphoreticular malignancy because of the presence of large cells having nuclei showing atypical features. The cytomorphological findings in three histopathologically documented cases of hyaline-vascular CD were evaluated to a set of cytomorphological criteria which could help in the identification of this condition on aspirate smears. The Papanicolaou and Diff-Quik stained smears from three cases of histologically documented hyaline-vascular CD were reviewed by one author. After review the following cytomorphological criteria were suggested to be indicators of the lesion. (i) The presence of large oval to round cells having ill-defined cytoplasmic margins and large nuclei with irregular nuclear outlines having fine or coarse chromatin giving a crumpled tissue paper appearance. (ii) A polymorphous population of lymphoid cells predominantly of small lymphocytes in the background. The smears from these three cases were then mixed with smears from four cases of reactive lymphoid hyperplasia and three cases of Hodgkin's lymphoma. These ten cases were blindly evaluated by two other cytopathologists in order to evaluate the utility of the proposed criteria in identifying CD. The cytomorphological criteria seen in the methodology section were present in all the cases. These features were helpful in distinguishing CD from reactive lymphoid hyperplasias and Hodgkin's Lymphomas in all cases except one case. Although hyaline-vascular CD is a difficult diagnostic entity on aspirate material the presence of large histiocytic cells with a crumpled tissue paper appearance of the nuclei in a background of small lymphocytes are useful indicators for suspecting this lesion. However, these findings should be analysed in larger studies to determine if they could in anyway reduce the diagnostic dilemma in cases of CD.