Limits...
Update to the College of American Pathologists reporting on thyroid carcinomas.

Ghossein R - Head Neck Pathol (2009)

Bottom Line: While there are defined criteria for invasion, there is not universal agreement in what constitutes capsular invasion, angioinvasion and extrathyroidal invasion.These findings assist clinicians in their assessment of the recurrence risk and potential for metastatic disease.Large meticulous clinico-pathologic and molecular studies with long term follow up are still needed in order to increase the impact of microscopic examination on the prognosis and management of TC.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, 10065, New York, NY, USA. ghosseir@mskcc.org

ABSTRACT

Background: The reporting of thyroid carcinomas follows the recommendations of the College of American Pathologists (CAP) protocols and includes papillary carcinoma, follicular carcinoma, anaplastic carcinoma and medullary carcinoma. Despite past and recent efforts, there are a number of controversial issues in the classification and diagnosis of thyroid carcinomas (TC) that, potentially impact on therapy and prognosis of patients with TC.

Discussion: The most updated version of the CAP thyroid cancer protocol incorporates recent changes in histologic classification as well as changes in the staging of thyroid cancers as per the updated American Joint Commission on Cancer staging manual. Among the more contentious issues in the pathology of thyroid carcinoma include the defining criteria for tumor invasiveness. While there are defined criteria for invasion, there is not universal agreement in what constitutes capsular invasion, angioinvasion and extrathyroidal invasion. Irrespective of the discrepant views on invasion, pathologists should report on the presence and extent (focal, widely) of capsular invasion, angioinvasion and extrathyroidal extension. These findings assist clinicians in their assessment of the recurrence risk and potential for metastatic disease. It is beyond the scope of this paper to detail the entire CAP protocol for thyroid carcinomas; rather, this paper addresses some of the more problematic issues confronting pathologists in their assessment and reporting of thyroid carcinomas.

Conclusion: The new CAP protocol for reporting of thyroid carcinomas is a step toward improving the clinical value of the histopathologic reporting of TC. Large meticulous clinico-pathologic and molecular studies with long term follow up are still needed in order to increase the impact of microscopic examination on the prognosis and management of TC.

Show MeSH

Related in: MedlinePlus

Minimal extra-thyroid extension (ETE) into peri-thyroid fat. The focus of ETE (between arrows) has a desmoplastic reaction (pale staining fibrous tissue). Note nearby thick walled blood vessel (V). Both findings are indicative of ETE
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2807537&req=5

Fig5: Minimal extra-thyroid extension (ETE) into peri-thyroid fat. The focus of ETE (between arrows) has a desmoplastic reaction (pale staining fibrous tissue). Note nearby thick walled blood vessel (V). Both findings are indicative of ETE

Mentions: Extrathyroidal extension refers to involvement of the perithyroidal soft tissues by a primary thyroid cancer. On gross examination, the capsule may appear complete but evidence has shown that microscopically the capsule is focally incomplete in a majority of autopsy thyroid glands evaluated [20]. The capsule includes sizable vascular spaces as well as small peripheral nerves and is continuous with the pretracheal fascia. [21]. In practice, since the fibrous capsule of the thyroid is often incomplete, the criteria for defining (minimal) extrathyroidal extension may be problematic and subjective. Diagnostic findings for minimal extrathyroidal extension includes the presence of carcinoma extending into perithyroidal soft tissues, including infiltration of adipose tissue and skeletal muscle, as well as around (and into) sizable vascular structures and nerves. Extension into adipose tissue can be problematic given the fact that adipose tissue can be found within the thyroid gland proper under normal conditions and also may be a component of a variety of thyroid lesions including carcinomas. [22]. As such, the presence of adipose tissue in association with a thyroid carcinoma should not be mistaken for extrathyroidal extension. Some authorities only accept invasion of skeletal muscle as the identifier for extrathyroidal extension. However, similar to adipose tissue in the thyroid, the presence of skeletal muscle may be seen in the thyroid gland under normal conditions, especially in relation to the isthmus portion of the thyroid gland, as well as in a variety of pathologic conditions [22]. If present, a desmoplastic response may be a helpful finding in the determination of extrathyroidal extension (Fig. 5). The identification of thick-walled vascular spaces and/or small peripheral nerves in association with adipose tissue may be of greater assistance as these structures are not located in the thyroid gland proper and their presence would be helpful in determining whether the carcinoma is extrathyroidal in extent (Fig. 5).Fig. 5


Update to the College of American Pathologists reporting on thyroid carcinomas.

Ghossein R - Head Neck Pathol (2009)

Minimal extra-thyroid extension (ETE) into peri-thyroid fat. The focus of ETE (between arrows) has a desmoplastic reaction (pale staining fibrous tissue). Note nearby thick walled blood vessel (V). Both findings are indicative of ETE
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2807537&req=5

Fig5: Minimal extra-thyroid extension (ETE) into peri-thyroid fat. The focus of ETE (between arrows) has a desmoplastic reaction (pale staining fibrous tissue). Note nearby thick walled blood vessel (V). Both findings are indicative of ETE
Mentions: Extrathyroidal extension refers to involvement of the perithyroidal soft tissues by a primary thyroid cancer. On gross examination, the capsule may appear complete but evidence has shown that microscopically the capsule is focally incomplete in a majority of autopsy thyroid glands evaluated [20]. The capsule includes sizable vascular spaces as well as small peripheral nerves and is continuous with the pretracheal fascia. [21]. In practice, since the fibrous capsule of the thyroid is often incomplete, the criteria for defining (minimal) extrathyroidal extension may be problematic and subjective. Diagnostic findings for minimal extrathyroidal extension includes the presence of carcinoma extending into perithyroidal soft tissues, including infiltration of adipose tissue and skeletal muscle, as well as around (and into) sizable vascular structures and nerves. Extension into adipose tissue can be problematic given the fact that adipose tissue can be found within the thyroid gland proper under normal conditions and also may be a component of a variety of thyroid lesions including carcinomas. [22]. As such, the presence of adipose tissue in association with a thyroid carcinoma should not be mistaken for extrathyroidal extension. Some authorities only accept invasion of skeletal muscle as the identifier for extrathyroidal extension. However, similar to adipose tissue in the thyroid, the presence of skeletal muscle may be seen in the thyroid gland under normal conditions, especially in relation to the isthmus portion of the thyroid gland, as well as in a variety of pathologic conditions [22]. If present, a desmoplastic response may be a helpful finding in the determination of extrathyroidal extension (Fig. 5). The identification of thick-walled vascular spaces and/or small peripheral nerves in association with adipose tissue may be of greater assistance as these structures are not located in the thyroid gland proper and their presence would be helpful in determining whether the carcinoma is extrathyroidal in extent (Fig. 5).Fig. 5

Bottom Line: While there are defined criteria for invasion, there is not universal agreement in what constitutes capsular invasion, angioinvasion and extrathyroidal invasion.These findings assist clinicians in their assessment of the recurrence risk and potential for metastatic disease.Large meticulous clinico-pathologic and molecular studies with long term follow up are still needed in order to increase the impact of microscopic examination on the prognosis and management of TC.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, 10065, New York, NY, USA. ghosseir@mskcc.org

ABSTRACT

Background: The reporting of thyroid carcinomas follows the recommendations of the College of American Pathologists (CAP) protocols and includes papillary carcinoma, follicular carcinoma, anaplastic carcinoma and medullary carcinoma. Despite past and recent efforts, there are a number of controversial issues in the classification and diagnosis of thyroid carcinomas (TC) that, potentially impact on therapy and prognosis of patients with TC.

Discussion: The most updated version of the CAP thyroid cancer protocol incorporates recent changes in histologic classification as well as changes in the staging of thyroid cancers as per the updated American Joint Commission on Cancer staging manual. Among the more contentious issues in the pathology of thyroid carcinoma include the defining criteria for tumor invasiveness. While there are defined criteria for invasion, there is not universal agreement in what constitutes capsular invasion, angioinvasion and extrathyroidal invasion. Irrespective of the discrepant views on invasion, pathologists should report on the presence and extent (focal, widely) of capsular invasion, angioinvasion and extrathyroidal extension. These findings assist clinicians in their assessment of the recurrence risk and potential for metastatic disease. It is beyond the scope of this paper to detail the entire CAP protocol for thyroid carcinomas; rather, this paper addresses some of the more problematic issues confronting pathologists in their assessment and reporting of thyroid carcinomas.

Conclusion: The new CAP protocol for reporting of thyroid carcinomas is a step toward improving the clinical value of the histopathologic reporting of TC. Large meticulous clinico-pathologic and molecular studies with long term follow up are still needed in order to increase the impact of microscopic examination on the prognosis and management of TC.

Show MeSH
Related in: MedlinePlus