PA19.1-6 | Hodgkin Lymphoma — Gross & Microscopic Identification — Summary & Reflection

REFLECT

A 24-year-old medical student presents to the pathology practical with a case: cervical lymph node, formalin-fixed. The slide shows diffuse effacement with a polymorphous infiltrate. You find one large binucleate cell with prominent eosinophilic nucleoli. Your colleague says: 'That could just be a large activated lymphocyte — I don't want to overcall HL.' What additional morphological features would you look for to strengthen or refute the diagnosis of HL? And what IHC panel would you request to resolve the uncertainty?

KEY TAKEAWAYS

Hodgkin Lymphoma — Specimen Identification Summary

Gross features:
• Enlarged, matted, rubbery lymph nodes
• Fish-flesh pale grey-white cut surface
• Nodular areas ± visible collagen bands (nodular sclerosis)
• Splenic: miliary white nodules on cut surface

The diagnostic cell — Reed-Sternberg cell:
• Large, binucleate/bilobed, mirror-image nuclei
• Large eosinophilic 'owl-eye' nucleoli with clear halo
• Abundant pale cytoplasm
• Variants: Hodgkin cell (mononuclear), lacunar cell (NS, retraction lacuna), popcorn/L&H cell (NLPHL, CD20+), mummified (LD)

Subtype histology:

IHC (cHL): CD30+, CD15+, CD45−, PAX5 dim+, CD20−
IHC (NLPHL): CD20+, CD45+, CD30−, CD15−

Practical approach: Low power → architecture (bands? nodules?) → medium power → background composition → high power → find RS cell → assign variant → correlate IHC.