Processing the entire capsule in thyroid follicular lesions improves diagnostic accuracy

There is contradictory evidence in literature with respect to diagnosis and management of follicular lesions of the thyroid gland. From surgical pathology stand point, pathologists require submission and processing of entire capsule for microscopic evaluation. This can be extremely challenging especially in larger lesions.

We studied the impact of submitting entire capsule on final pathologic diagnosis in cases on which only representative sections were submitted initially and entire capsule was submitted subsequently.

A total of 80 specimens were identified. Mean size of the nodule in these cases was 4.4 ± 1.9 cm. Mean initial tissue sections submitted were 11.6 ± 3.6. Entire capsule was submitted subsequently in an additional 12.6 ± 13.3 sections. Submission of entire capsule contributed to final diagnosis in 3 (3.8%) cases whereby foci of capsular microinvasion were identified. There was no significant difference in the requirement of subsequent sections in specimens grossed by residents compared to those grossed by pathologist assistants (10.4 ± 10.8 vs. 14.4 ± 14.9, p = 0.18). The processing cost of additional sections of capsule was $ 4143 in these cases.

Processing of entire capsule in thyroid follicular lesions has a definitive yield that comes at a high cost. Thin slicing and looking for areas of gross abnormality such as mushrooming may be more practical especially in larger lesions.