Thyroid & parathyroid
Low risk thyroid tumors
WDT-UMP
Author: Shuanzeng (Sam) Wei, M.D., Ph.D.
Last author update: 1 January 2017
Last staff update: 28 August 2023
Copyright: 2003-2024, PathologyOutlines.com, Inc.
PubMed Search: well differentiated neoplasm of uncertain malignant potential OR WDT-UMP
Table of Contents
Definition / general | Essential features | Diagrams / tables | Prognostic factors | Gross description | Microscopic (histologic) description | Microscopic (histologic) images | Cytology description | Cytology images | Positive stains | Differential diagnosis | Additional referencesCite this page: Wei S. WDT-UMP. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/thyroidwelldiffump.html. Accessed December 20th, 2024.
Definition / general
- Follicular neoplasm with equivocal nuclear features of papillary thyroid carcinoma and questionable capsular or vascular invasion
- Most cases behave in an indolent manner (Arch Pathol Lab Med 2006;130:984)
- Diagnosis is based on morphologic criteria; immunostains are not reliable
- Terminology was proposed by Chernobyl pathologists to avoid unnecessary aggressive treatment (Int J Surg Pathol 2000;8:181, Arch Pathol Lab Med 2006;130:984)
Essential features
- Follicular neoplasm with equivocal nuclear features of papillary thyroid carcinoma and questionable capsular or vascular invasion
Diagrams / tables
Images hosted on other servers:
Schematic drawing for capsular invasion
Schematic drawing for vascular invasion
Prognostic factors
- Excellent prognosis with lobectomy
Gross description
- Well circumscribed or encapsulated solid nodule
Microscopic (histologic) description
- Well circumscribed or encapsulated follicular neoplasm with equivocal nuclear features of papillary thyroid carcinoma and questionable capsular or vascular invasion
Microscopic (histologic) images
Contributed by Shuanzeng Wei, M.D., Ph.D.
Questionable nuclear features of papillary carcinoma
Cytology description
- Can have subtle nuclear grooves, but no nuclear pseudoinclusion (Endocr J 2012;59:483)
Cytology images
Images hosted on other servers:
Cytological features of WDT-UMP
Positive stains
- Can be positive for HBME1 (Mod Pathol 2005;18:541)
Differential diagnosis
- Follicular tumor of uncertain malignant potential (FT-UMP): encapsulated follicular neoplasm with equivocal vascular or capsular invasion, without nuclear features of papillary carcinoma (Endocr Pathol 2005;16:279)
- Noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP): encapsulated follicular neoplasm with nuclear features of papillary carcinoma, without vascular or capsular invasion (JAMA Oncol 2016;2:1023)
