Cytologically Yours: Unknowns: 201310: Case 5

Clinical History

46 yo male with a new left upper lobe nodule. He has a history of rheumatoid arthritis and welding. This is a FNA of the nodule.

Cytology

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  GMS
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  Mucicarmine

Resident Question

• <spoiler text="Diagnosis">

Cryptococcus </spoiler>

• <spoiler text="List three facts about this organism">
• Peripheral nodular lesions or multiple lesions with necrosis and granulomatous response
• Found in bird droppings and soil contaminated with bird droppings
• Variably sized yeast forms
  • Can measure 4-6um and are round/oval
• Narrow based asymmetric budding
• Mucicarmine + halo
• GMS can highlight budding
• India Ink highlights capsule

</spoiler>

Additional Teaching Points

Mimics

• Pneumocystis
  • Smaller
  • Tight casts
• Candida
  • Equal sized yeast
  • No capsule
  • Pseudohyphal structures