Clinical features :
Male patient, 75 years old. Large nodular lesion since 5 years. Total thyroidectomy with exerese of a large tumor adherent to the posterior structures.

Gross features :
Solitary right 6,5 cm nodule, firm, gray- white, macroscopically extra thyroid nodule.

Microscopy :
Pure papillary proliferation of long cohesive parallel papillae with rare follicular differenciation (fig A, fig B).
		fig. A
Those structures are covered with tall tumoral cells (more than twice as tall as they are wide), with acidophilic and slighty granular cytoplasm (but no oncocytic).
		fig. B
The nuclei show some papillary nuclear features especially grooved nuclei, without ground glass and pseudo inclusions. Mitosis are more numerous than in classical form (fig C, fig D). The stroma is made of hyaline fibrous strand, without psammomas bodies.
		fig. C
This tumor has a macroscopic extra thyroid extension with striated muscle involvment around thyroid capsule. Posterior surgical resection is incomplete.
		fig. D

Diagnosis :
Papillary thyroid carcinoma, tall cell variant, macroscopic extra thyroid extension stage pT4. Non in sano resection.

Comments :
In this case, the diagnostic of papillary carcinoma is obvious but the Pathologist must recognize several features of pronostic importance, apart clinical information (older male patient).
These features are :
-    the pathologic stage of the tumor : extra-thyroid extension with incomplete resection
-    the tall-cell cytologic variant which is said to be more aggressive than classical form
(25 % of mortality for Hawk and Hazard). It is not easy to discern how much this form contributes to worsen the prognosis because there is often several unfavorable features associated like in this case : advanced age, high stage, large size.

References :

JOHNSON T.L., LLYOD R.V., THOMPSON N.W., BEIERWALTES W.H., SISSON J.C.
Prognostic implications of the tall cell variant of papillary thyroid carcinoma.
Am J Surg Pathol. 1988 ; 12 : 22-27.

OSTROWSKI M.L., MERINO M.J.
Tall cell variant of papillary thyroid carcinoma.
Am J Surg Pathol 1996 ; 20 : 964-974.

TERRY J.H., St JOHN S.A., KARKOWSKI F.J., et coll
Tall cell papillary cancer : incidence an prognosis.
Am J Surg Pathol 1994 ; 168 : 459-461.