CYTOPATHOLOGY INTERESTING CASE #4pathology.med.upenn.edu/sites/default/files/ic.cytopath.ptc_tall_cell_variant.wo1_.2-2...– Nuclear grooves and intranuclear inclusion including multiple

CYTOPATHOLOGY INTERESTING CASE #4

65 year old man with 2.3 cm right lower thyroid nodule.

Submitted & Prepared by – Jalal Jalaly, MBBS & Zubair Baloch, MD

US-FNA (Onsite smears and ThinPrep)Please click on thumbnails for full view slides

Surgical Pathology Follow-up

DiagnosisPapillary Thyroid Carcinoma (PTC), Tall Cell Variant

Key facts

• Epidemiology

• Key cytomorphological features

• Molecular findings

• References

PTC-Tall Cell Variant

Epidemiology:– 1.3–12% of all papillary thyroid carcinomas

– Commonly present at an older age (54.3 years)

– Aggressive variant of PTC with higher extrathyroidalextension and shortened survival compared to classical PTC

– The wide range of prevalence (1.3-12%) reflects lack of agreement on percentage of tall cells required for diagnosis (as per 4th edition of WHO the diagnosis of PTC-Tall cell variant

requires 30% of tall cells)

PTC-Tall Cell Variant

Key cytomorphological features:

– Architecture:

– Papillary groups or cellular fragments

– Cytoplasm:

– Elongated/ tall cell with height at least twice or thrice their width

– Oncocytic cytoplasm with distinct cell borders

– Nuclear Features:

– Elongated nuclei with crowding and overlapping

– Prominent central nucleoli

– Nuclear grooves and intranuclear inclusion including multiple inclusions (AKA Soap bubble appearance)

PTC-Tall Cell Variant

• Molecular findings:

– BRAF mutation is more common in PTC-TCV compared to classical PTC

– Loss of heterozygosity for chromosome 1, p53 gene, and RET/PTC3 rearrangement

PTC – Tall Cell Variant

• References:• Solomon A, Gupta PK, LiVolsi VA, Baloch ZW. Distinguishing tall cell

variant of papillary thyroid carcinoma from usual variant of papillary thyroid carcinoma in cytologic specimens. Diagn Cytopathol. 2002 Sep;27(3):143-8.

• Ghossein R, Livolsi VA. Papillary thyroid carcinoma tall cell variant. Thyroid. 2008 Nov 1;18(11):1179-81.

• Baloch ZW, LiVolsi VA. Special types of thyroid carcinoma. Histopathology. 2018 Jan 1;72(1):40-52.