a potential pitfall to be aware of in head and neck FNAC practice
• 70-year-old man presents with a mass in left lateral zygoma.
•On U/S there was a hypoechoic lesion in the left parotid 1.3 x 0.9 cm, and a further probable lymph node 0.5 cm in the left zygomatic area.
•Following informed consent an FNA was taken from the left parotid lesion
Cytology findings
• Cellular, malignant aspirate
•Loosely cohesive groups of pleomorphic epithelioid cells
•The clusters have rounded borders with some cells showing vacuolated cytoplasm
•Malignant undifferentiated sample pending IHC
•Unfortunately the clot preparation did not contain sufficient tumour cells for immunohistochemistry
Important clinical correlation
•Excision of a lump on the ipsilateral forehead 1 year previous, histology reported as poorly differentiated squamous carcinoma
•Review of histology revealed this was an unusual subtype of SCC, containing cells identical to those seen in the cytology preparation
Previous histology reviewed. Note acantholysis / gland-like spaces
Also note dyscohesive rounded tumour cells similar to those in the cytology preparations
Note perineural invasion
CEA was negative (excluding true glandular differentiation); note sweat gland +ve control
if you are a British Cytology member you can download the full presentation at this link https://www.britishcytology.org.uk/case-studies/august-case-study-cytology-histology-correlation-confirms-an-unusual-variant-of-a-common-malignancy