Solid Cell Nest
Lester D. R. Thompson, MD
Key Facts
Terminology
Small remnant of ultimobranchial apparatus, associated with development of thyroid C-cells
Clinical Issues
Posteromedial and lateral area of bilateral middle to upper 1/3 of thyroid lobes
Microscopic Pathology
50 to 1,000 µm in greatest dimension
Interfollicular distribution of well-demarcated, irregular small nests
Small epithelial cells, ovoid to polygonal
Nuclei are ovoid, with evenly distributed chromatin
Frequent longitudinal nuclear groove
No keratinization or intercellular bridges
High density of C-cells intermingled with SCNs
Ancillary Tests
Positive: p63, pCEA; negative: Thyroglobulin, TTF-1
 There is a well-demarcated collection of epithelial cells identified in an interfollicular distribution. Follicles are entrapped  by the proliferation in a number of foci. C-cells are present  . |
 In many SCNs, the epithelial cells show a compact arrangement, surrounded by a basement membrane. Cytologic atypia is absent, as are mitoses. |
TERMINOLOGY
Abbreviations
Solid cell nests (SCNs)
Ultimobranchial body (UBB) Definitions
Small remnant of ultimobranchial apparatus, associated with development of thyroid C-cells
ETIOLOGY/PATHOGENESIS
Pathogenesis
May be derived from branchial pouch remnants
May be derived from ultimobranchial body vestiges (endoderm)
High density of C-cells intermingled with SCNs
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
