A 43-year-old male presented with a rapidly enlarging chest wall mass. Imaging showed a large pleural-based mass involving the ribs. Fine needle aspiration of the mass showed clusters and scattered pleomorphic plasmacytoid cells, suggestive of malignancy. Differential diagnoses included mesothelioma, solitary fibrous tumor, and plasmacytoma. Microscopic examination revealed features consistent with mesothelioma, including spherical clusters with knobby edges, papillary clusters, and dissociated cells exhibiting a low nucleus-to-cytoplasm ratio and binucleation. Immunocytochemistry testing was recommended to confirm mesothelioma. The case report discussed cytological features of

1. Interesting Case - Cytology
Dr Tamil Nila M

2. Case History
A 43 year old male came with complaints of Anterior chest wall
swelling that was rapidly progressing in size for the past 1.5 months

5. Radiology report
• Large pleural based mass lesion measuring 12 x 10 cm in the right
chest wall
• Compression of the right lung with erosion of 2nd , 3rd and 4th ribs.
• Impression:
• Picture of Mesothelioma

6. FNAC

8. Microscopy
• Smears studied show scattered and clusters of pleomorphic
plasmacytoid cells with eccentrically placed nucleus in a
haemorrhagic background
• Smears positive for malignancy
• Kindly do tissue biopsy for confirmation and further evaluation

9. DD – Pleural based lesions
• Mesothelioma
• Solitary fibrous Tumour
• Plasmacytoma
• Metastases

10. Mesothelial cells
• Single & small clusters
• Uniform
• Window
• Round cells
• Round, central/eccentrically
placed nuclei
• Prominent nucleoli
• Well defined cytoplasmic border
• Cytoplasmic blebs
Cytochemistry
Alcian Blue
PAS
Immunocytochemistry
Calretinin

11. Mesothelioma
• Pattern
• Spherical clusters with knobby edges
• Papillae like clusters
• Dissociated cells
• Cell in cell (cannibalism)
• Mesothelial cell morphology
• Enlarged cells
• Low N:C Ratio
• Binucleation/ Multinucleation
• Centrally placed nucleus with large prominent nucleoli (macronucleoli)
• Condensed cytoplasm with ring-like peripheral clear zone

12. Solitary fibrous tumour
• Bloody aspirate
• Oval to elongated spindle cells
• Short fascicles
• Scanty cytoplasm
• Elongated spindle-shaped nucleus with pointed ends
• Reticular nuclear chromatin
• Naked nuclei and ropy collagen in the background

13. Plasmacytoma
• Many plasma cells
• Uniformly dispersed
• Single cell presentation
• Variable cell differentiation

14. Metastases
Male Female
Lung
Hematological malignancy
Gastrointestinal Malignancy
Breast
Lung
Gynecological
GIT

15. Malignant cells - Features
• Cell Arrangement
• Cannon ball-like tight 3D clusters
• Papillary clusters
• Single (Small cell Ca lung)
• Small rows (Lobular Ca Breast)
• Cytoplasm
• Vacuolated
• Keratin (SCC)
• Mucous (Adeno Carcinoma)
• Melanin (Melanoma)

16. Malignant cells – features
• Nucleus
• High N:C ratio
• Large
• Plemorphic
• Irregular nuclear margin
• Prominent nucleoli
• Coarse chromatin
• Mitosis
• Tripolar mitosis
• Cannibalism
• Psammoma bodies

17. Squamous cell carcinoma
• Small clusters / discrete cell population
• Keratinising SCC – Polyhedral Cells
• Non Keratinising SCC – Oval cells
• Cytoplasm: Dense & Orangeophilic
• Nucleus: Hyperchromatic
• Inconspicuous nucleoli
• Cytoplasmic Vacuoles – Degenerative changes

18. Adenocarcinoma
• Two cell population
• Tight spherical ball like clusters of cells
• Nuclear overlappin & Crowding
• Cell Cannibalism
• Bi or Multinucleation present
• Prominent nucleoli
• Vacuolated cytoplasm

19. Small cell lung carcinoma
• Arrangement: Small clusters/ Discrete/ Small
Chains
• 2 X Diameter of Lymphocyte
• Scanty Cytoplasm
• Nuclear molding/ Angulations
• Granular chromatin
• Inconspicous Nucleoli

20. References
• Bibbo M., Wilbur D. Comprehensive Cytopathology .2015
• Orell and sterretts Fine needle aspiration cytology, 5th-edition
• Diagnostic Cytology, Pranab dey
• Atlas of Serous Fluid Cytopathology, Arthur I Spriggs