Canadian Association of Pathologists - Case of the Month - July, 2007
Case 3: "Unilateral cervical lymphadenopathy"
Explanation:
This highly cellular sample shows numerous abnormal large cells against a background that includes morphologically normal small lymphocytes and granulocytes. Classical Reed-Sternberg and RS variants are present in large numbers. Histologic examination of the node confirmed Nodular Sclerosing Hodgkin Lymphoma, cellular phase.
Reed-Sternberg cells in air dried and Giemsa stained preparations are characterized by extremely fragile and pale cytoplasm and large (often huge) inclusion like nucleoli which appear pale blue against the finely reticulated purple or amphophilic nucleus. In rare instances the nucleoli may stain brick red.
Teaching Points:
- The finding of abnormal large cells against a background of normal lymphoid cells should prompt a differential diagnosis of Hodgkin lymphoma and its mimics including anaplastic large cell lymphoma, T-cell lymphoma, and metastatic tumours such as melanoma and nasopharyngeal carcinoma.
- Immunohistochemical confirmation of the diagnosis is critical but may be difficult unless a good cell block preparation is available. The fragility of the RS cells causes the immunoreactive cytoplasm to be lost when cytospin preparations are prepared.