Human Papillomavirus-Related Neuroendocrine Carcinomas of the Head and Neck

Abstract

Human papillomavirus (HPV)-related head and neck carcinoma (HNC) represents an important subgroup of head and neck cancer that is characterized by a consistent microscopic appearance and a favorable prognosis. A growing experience with HPV testing, however, has uncovered variants that deviate from the prototypic HPV-HNC with respect to morphology. While these HPV-HNCs may deviate morphologically from the prototype, they do not appear to stray far from the favorable clinical outcome assigned to HPV-positive status. In effect, HPV positivity trumps traditional prognostic features predicated on morphology such as tumor grade and histologic subtype when it comes to predicting clinical behavior. For the diagnostic pathologist, the pedestrian task of tumor grading and subtyping would seem to be of little prognostic or therapeutic relevance when it comes to HPV-HNC. Recognition and documentation of neuroendocrine differentiation is a most notable exception. Forms of HPV-HNC have now been reported that morphologically resemble small cell carcinoma (SCC) and large cell neuroendocrine carcinoma (LCNEC) of other sites, and that immunohistochemically exhibit neuroendocrine differentiation. Despite the presence of HPV, these SCCs and LCNECs share the same aggressive clinical behavior of their counterparts in the lung and other sites where the high grade neuroendocrine phenotype is associated with early distant spread and poor overall survival. Consequently, the high grade neuroendocrine phenotype should be regarded as an aggressive form of HPV-HNC where tumor morphology displaces HPV positivity as the most important prognostic feature.

http://ift.tt/2ppqQoL

Proceedings of the NASHNP Companion Meeting, March 18th, 2018, Vancouver, BC, Canada: Salivary Neuroendocrine Carcinoma—An Overview of a Rare Disease with an Emphasis on Determining Tumor Origin

Abstract

Salivary neuroendocrine carcinomas are rare and the overwhelming majority is high-grade. The parotid gland is the most commonly involved site followed by the submandibular gland. Most arise de novo but rare examples occurring as a high-grade transformation of another type of salivary gland neoplasm exist. There is significant morphologic and immunophenotypic overlap with neuroendocrine carcinomas of other sites, especially the skin. Like cutaneous neuroendocrine (or Merkel cell) carcinomas, approximately three-fourths are cytokeratin 20 positive. Cytokeratin 20 positive salivary neuroendocrine carcinomas are often referred to as being of the 'Merkel cell type' since most other non-cutaneous neuroendocrine carcinomas are cytokeratin 20 negative. Salivary neuroendocrine carcinomas may be challenging to separate from Merkel cell carcinomas of the head and neck on pathologic grounds because the latter often metastasize to the parotid gland. Clinical history is often relied upon to separate primary salivary tumors from cutaneous metastases but may not be helpful in all cases. Here we review the clinical, pathologic and molecular features of salivary neuroendocrine carcinomas focusing on high-grade major salivary gland tumors. The difficulty in separating salivary tumors from metastatic Merkel cell carcinoma will be highlighted.

http://ift.tt/2FN6Yq3

Update on Merkel Cell Carcinoma

Abstract

Merkel cell carcinoma (MCC) is an aggressive cutaneous neuroendocrine carcinoma. Incidence of MCC continues to rise, and risk factors include advanced age, pale skin, chronic sun exposure, and immune suppression. Diagnosing MCC utilizes a combination of morphology and immunohistochemistry. Merkel cell polyomavirus (MCPyV) is present in approximately 70–80% of MCCs and represents a key pathogenic driver in those MCCs. In contrast, MCPyV-negative MCCs arise through progressive accumulation of ultraviolet-light induced somatic mutations. Staging of MCC proceeds according to the American Joint Commission on Cancer (AJCC) 8th Edition, which utilizes features of the primary tumor together with regional lymph node(s) (clinically and/or pathologically detected) and/or distant metastases. Many potentially useful biomarkers have been studied to refine risk stratification in MCC. In recent years, the host immune infiltrate has been leveraged as immune checkpoint blockade has emerged as an efficacious mode of treatment for patients with advanced MCC.

http://ift.tt/2tYqfis

Human Papillomavirus-Related Neuroendocrine Carcinomas of the Head and Neck

Abstract

Human papillomavirus (HPV)-related head and neck carcinoma (HNC) represents an important subgroup of head and neck cancer that is characterized by a consistent microscopic appearance and a favorable prognosis. A growing experience with HPV testing, however, has uncovered variants that deviate from the prototypic HPV-HNC with respect to morphology. While these HPV-HNCs may deviate morphologically from the prototype, they do not appear to stray far from the favorable clinical outcome assigned to HPV-positive status. In effect, HPV positivity trumps traditional prognostic features predicated on morphology such as tumor grade and histologic subtype when it comes to predicting clinical behavior. For the diagnostic pathologist, the pedestrian task of tumor grading and subtyping would seem to be of little prognostic or therapeutic relevance when it comes to HPV-HNC. Recognition and documentation of neuroendocrine differentiation is a most notable exception. Forms of HPV-HNC have now been reported that morphologically resemble small cell carcinoma (SCC) and large cell neuroendocrine carcinoma (LCNEC) of other sites, and that immunohistochemically exhibit neuroendocrine differentiation. Despite the presence of HPV, these SCCs and LCNECs share the same aggressive clinical behavior of their counterparts in the lung and other sites where the high grade neuroendocrine phenotype is associated with early distant spread and poor overall survival. Consequently, the high grade neuroendocrine phenotype should be regarded as an aggressive form of HPV-HNC where tumor morphology displaces HPV positivity as the most important prognostic feature.

http://ift.tt/2ppqQoL

Proceedings of the NASHNP Companion Meeting, March 18th, 2018, Vancouver, BC, Canada: Salivary Neuroendocrine Carcinoma—An Overview of a Rare Disease with an Emphasis on Determining Tumor Origin

Abstract

Salivary neuroendocrine carcinomas are rare and the overwhelming majority is high-grade. The parotid gland is the most commonly involved site followed by the submandibular gland. Most arise de novo but rare examples occurring as a high-grade transformation of another type of salivary gland neoplasm exist. There is significant morphologic and immunophenotypic overlap with neuroendocrine carcinomas of other sites, especially the skin. Like cutaneous neuroendocrine (or Merkel cell) carcinomas, approximately three-fourths are cytokeratin 20 positive. Cytokeratin 20 positive salivary neuroendocrine carcinomas are often referred to as being of the 'Merkel cell type' since most other non-cutaneous neuroendocrine carcinomas are cytokeratin 20 negative. Salivary neuroendocrine carcinomas may be challenging to separate from Merkel cell carcinomas of the head and neck on pathologic grounds because the latter often metastasize to the parotid gland. Clinical history is often relied upon to separate primary salivary tumors from cutaneous metastases but may not be helpful in all cases. Here we review the clinical, pathologic and molecular features of salivary neuroendocrine carcinomas focusing on high-grade major salivary gland tumors. The difficulty in separating salivary tumors from metastatic Merkel cell carcinoma will be highlighted.

http://ift.tt/2FN6Yq3

Human Papillomavirus-Related Neuroendocrine Carcinomas of the Head and Neck

Abstract

Human papillomavirus (HPV)-related head and neck carcinoma (HNC) represents an important subgroup of head and neck cancer that is characterized by a consistent microscopic appearance and a favorable prognosis. A growing experience with HPV testing, however, has uncovered variants that deviate from the prototypic HPV-HNC with respect to morphology. While these HPV-HNCs may deviate morphologically from the prototype, they do not appear to stray far from the favorable clinical outcome assigned to HPV-positive status. In effect, HPV positivity trumps traditional prognostic features predicated on morphology such as tumor grade and histologic subtype when it comes to predicting clinical behavior. For the diagnostic pathologist, the pedestrian task of tumor grading and subtyping would seem to be of little prognostic or therapeutic relevance when it comes to HPV-HNC. Recognition and documentation of neuroendocrine differentiation is a most notable exception. Forms of HPV-HNC have now been reported that morphologically resemble small cell carcinoma (SCC) and large cell neuroendocrine carcinoma (LCNEC) of other sites, and that immunohistochemically exhibit neuroendocrine differentiation. Despite the presence of HPV, these SCCs and LCNECs share the same aggressive clinical behavior of their counterparts in the lung and other sites where the high grade neuroendocrine phenotype is associated with early distant spread and poor overall survival. Consequently, the high grade neuroendocrine phenotype should be regarded as an aggressive form of HPV-HNC where tumor morphology displaces HPV positivity as the most important prognostic feature.

http://ift.tt/2ppqQoL

Proceedings of the NASHNP Companion Meeting, March 18th, 2018, Vancouver, BC, Canada: Salivary Neuroendocrine Carcinoma—An Overview of a Rare Disease with an Emphasis on Determining Tumor Origin

Abstract

Salivary neuroendocrine carcinomas are rare and the overwhelming majority is high-grade. The parotid gland is the most commonly involved site followed by the submandibular gland. Most arise de novo but rare examples occurring as a high-grade transformation of another type of salivary gland neoplasm exist. There is significant morphologic and immunophenotypic overlap with neuroendocrine carcinomas of other sites, especially the skin. Like cutaneous neuroendocrine (or Merkel cell) carcinomas, approximately three-fourths are cytokeratin 20 positive. Cytokeratin 20 positive salivary neuroendocrine carcinomas are often referred to as being of the 'Merkel cell type' since most other non-cutaneous neuroendocrine carcinomas are cytokeratin 20 negative. Salivary neuroendocrine carcinomas may be challenging to separate from Merkel cell carcinomas of the head and neck on pathologic grounds because the latter often metastasize to the parotid gland. Clinical history is often relied upon to separate primary salivary tumors from cutaneous metastases but may not be helpful in all cases. Here we review the clinical, pathologic and molecular features of salivary neuroendocrine carcinomas focusing on high-grade major salivary gland tumors. The difficulty in separating salivary tumors from metastatic Merkel cell carcinoma will be highlighted.

http://ift.tt/2FN6Yq3