Color Atlas of Hematology - Practical Microscopic and Clinical ...

176Cytology of Organ Biopsies and ExudatesReactive Lymph Node Hyperplasia andLymphogranulomatosis (Hodgkin Disease)Reactive lymph node hyperplasia of whatever etiology is characterized by aconfused mixture of small, middle-sized, and large lymphocytes. Whenthe latter have a nuclear diameter at least three times the size of the predominatingsmall lymphocytes and have a fair width of basophilic cytoplasm,they are called immunoblasts (lymphoblasts). Cells with deeplybasophilic, eccentric cytoplasm and dense nuclei are called plasmablasts,and cells with a narrow cytoplasmic seam are centroblasts. Lymphocytescan also to varying degrees show a tendency to appear as plasma cells, e.g.,as plasmacytoid lymphocytes with a relatively wide seam of cytoplasm.Monocytes and phagocytic macrophages are also seen (Fig. 63).Table 30 (p. 178) summarizes the different forms of reactive lymphadenitis.The basic cytological findings in all of them is always a completemixture of small to very large lymphocytes. Occasionally more specificfindings may indicate the possibility of mononucleosis (increased immaturemonocytes) or toxoplasmosis (plasmablasts, phagocytic macrophages,and possibly epithelioid cells).Any enlargement of the lymph nodes that persists for more than twoweeks should be subjected to histological analysis unless the history, clinicalfindings, serology, or CBC offer an explanation.At first sight, the confusion visible in the cytological findings of lymphogranulomatosis(Hodgkin disease) is reminiscent of the picture in reactivehyperplasia (something which may be important for an understanding ofthe pathology of this disease compared with other malignant neoplasms).However, some cells elements show signs of a strong immunological“over-reaction” in which large, immunoblast-like cells form with welldevelopednucleoli (Hodgkin cells). Sporadically, some of these cells arefound to be multinucleated (Reed–Sternberg giant cells); infiltrations ofeosinophils and plasma cells may also be found. Findings of this type alwaysrequire histological analysis, which can distinguish between fourprognostically relevant histological subtypes. In addition to this, the verylack of a clear demarcation between Hodgkin disease and reactive conditionsis reason enough to conduct a histological study of every lymph nodethat appears reactive if does not regress completely within two weeks.In cases of histologically verified Hodgkin disease, cytological analysisis especially useful in the assessment of new lymphomas after therapy.