Background: The most common of the aggressive variant of papillary thyroid carcinoma
(PTC) is the tall cell variant (TCV). Because there are serious prognostic and management
implications to a diagnosis of TCV, we review the entity to inform clinicians about the many
facets of TCV. Summary: The TCV of PTC is characterized by cells having the nuclear
features of PTC and whose height is at least twice or thrice their width. There is
disagreement regarding the proportion of tall cells and the cell height required to diagnose …

Papillary thyroid carcinoma tall cell variant (PTC‐TCV), a form of PTC regarded as an
aggressive subtype, shares several morphologic features with oncocytic tumors. Pathogenic
homoplasmic/highly heteroplasmic somatic mitochondrial DNA (mtDNA) mutations, usually
affecting oxidative phosphorylation (OXPHOS) complex I subunits, are hallmarks of
oncocytic cells. To clarify the relationship between PTC‐TCV and oncocytic thyroid tumors,
17 PTC‐TCV and 16 PTC non‐TCV controls (cPTC) were subjected to:(1) transmission …