Cytologically Yours: CoW: 20131216

Clinical Summary

The patient is an 66 year old white male with a history of smoking, COPD, and diabetes. The patient presented with increased shortness of breath.

Past Medical History

• Diabetes
• COPD
• Squamous cell carcinoma of skin

Past Surgical History

• Excision of squamous cell carcinoma
• Removal of adenomatous polyp of sigmoid colon

Clinical Plan

The differential diagnosis includes worsening of COPD. CT imaging of chest is performed.

Radiology

• CT Chest shows hilar lung mass and multiple mediastinal lymph nodes showing increased uptake on PET scan.

Pathology

Cytology

• 
  10x magnification of pleural fluid(ThinPrep). Groups of cohesive epithelial appearing cells are seen on low power.
• 
  40x magnification of pleural fluid (ThinPrep). Cluster of atypical cells showing nuclear pleomorphism and scant cytoplasm.
• 
  40x magnification of pleural fluid (ThinPrep). Chromatin is irregular and clumped with salt and pepper appearance; although, occasional nucleoli are also seen.
• 
  40x magnification of pleural fluid (ThinPrep). Some nuclear molding can be appreciated and a mitotic figure is present.
• 
  Cell block of pleural fluid. Group of malignant cells showing nuclear molding, scant cytoplasm, and salt and pepper chromatin. Nucleoli are also seen.

Immunohistochemistry

• 
  CD56 on pleural fluid shows positive cytoplasmic staining.
• 
  Synaptophysin on pleural fluid shows positive cytoplasmic staining.

Other immunostains performed

• BerEp4 Positive
• Moc31 Faintly positive
• Calretinin Negative
• TTF1 Negative
• Chromogranin Positive
• Synaptophysin Positive
• CD56 Positive
• Napsin A Negative

Resident Questions

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Final Diagnosis

Cytology

• Small cell carcinoma

Case Discussion

This is a classic case of metastatic small cell carcinoma in pleural fluid.