FNA cytology practice Flashcards
Case 1
Think about this case:
5yo FN Labrador retriever
1cm erythematous nodule on dorsal aspect of radius
D/dx Penetrating wound causing infection/inflammation / cellulitis, insect bite with inflammation, MCT, histiocytoma, plasmacytoma, cutanoeus lymphoma, adnexal or mesenchymal tumour with inflammation
Little changed since first seen 2 weeks previously, though does appear to cause some irritation
Diagnosis
- MCT – cytology suggests grade 2 or perhaps 3
- Metastatic potential so screen local lymph node +/- liver and spleen
- Wide excision required
- Histology to check margins and for grading
Case 2
Think about this case:
3 yo FN Miniature Poodle, recently neutered at your surgery, when no abnormalities were detected
1.5cm diameter firm, painless interscapular nodule has subsequently developed
d/dx Injection reaction, microchip reaction, tumour eg spindle cell tumour, cyst, adnexal tumour, MCT
- Mixed inflammation within adipose tissue
- = panniculitis
- No evidence of infection
- Classical appearance of an injection reaction
- Usually resolves spontaneously
Case 3
Think about this case:
9yo MN Staffordshire Bull Terrier
3cm diameter well-defined soft mass on medial thigh. Enlarged slightly over past 6 months.
DDX lipoma, benign cyst, MCT, low grade spindle cell tumour, low grade adnexal tumour
Lipoma
NB subcutanoeus fat appears identical
If fat is aspirated but the lesion looks aggressive, you may have an unrepresentative sample - repeat the aspirate if in doubt
Fat is commonly aspirated when attempting prescap and pop lymph node aspirates
Case 4
Think about this case:
12yo MN DSH cat
Ill-defined swelling on left dorsal scapular region, noted first 3 days ago.
DDX:
abscess / cellulitis
Sarcoma eg haemangiosarcoma, osteosarcoma
(Enlarged prescap lymph node eg due to metastic neoplasia)
Mast cell tumour
Septic inflammation
There are many neutrophils
These do not appear significantly degenerate but there are intracellular bacteria indicating infection
This is consistent with an abscess / area of cellulitis eg due to a cat bite
Case 5
Think about this case:
8yo ME Boxer
4cm diameter well-defined soft mass on medial thigh, present unchanged for several months
Soft mass and lack of progression over months suggests a benign process, eg lipoma.
Other ddx : benign cyst MCT, low grade spindle cell tumour, low grade adnexal tumour
Mast cell tumour
Marked variation in cell and nuclear size and in granularity indicates not well differentiated
In spite of the clinical history
Never assume – always investigate skin masses!
Case 6
Think about this case:
11yo ME Labrador
Irregular, ill-defined firm nodule, 6cm diameter, over right caudal radius. Noted to have increased in size over past month
FNA consistent with spindle cell tumour
Biopsy required for histopathological diagnosis
Haemangiopericytoma confirmed on incisional biopsy (NB this spindle cell tumour yields more cells than most others)
Locally invasive but infrequently metastasise
Complete surgical excision if possible. +/-radiotherapy if needed
Case 7
Think about this case:
1 yr crossbreed dog
Mass on pinna which grew quickly
Been present for 3 weeks
DDX histiocytoma, plasmacytoma, trichoblastoma, Cutanoeus lymphoma
Histiocytoma
Usually arises in young dogs
Head and feet are common sites
May see just histiocytes
+/- small lymphocytes = immune response leading to regression.
