Cutaneous Squamous Cell Carcinoma with Metastasis to the Parotid: A Single-Center Retrospective Histopathological Observational Study

Monday, October 13, 2025

1:30 PM - 1:36 PM EDT

Location: 127

Disclosure(s):

Mayuri A. Yasuda, MD:

faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.

Eric J. Thorpe, MD:

faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.

Swati Mehrotra, MD:

faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.

Andrea M. Ziegler, MD:

faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.

Introduction: Cutaneous squamous cell carcinoma (cSCC) is the second most common malignancy after basal cell carcinoma. Metastasis to the parotid gland is an uncommon but adverse manifestation of primary cSCC (pcSCC). There has been little investigation regarding the histopathological patterns of pcSCC metastasis to the parotid. This study aims to evaluate the histological patterns of metastasis of pcSCC to the parotid and correlate with recurrence rates and overall survival.

Methods: This was a retrospective chart review of all patients at LUMC between 2016 and 2022 who had pcSCC with metastasis to the parotid. Patients who had direct involvement of the parotid gland were excluded. The histological slides from the parotidectomy surgery were reviewed to determine the worst pattern of invasion (WPOI). The patient’s history, operative reports, surgical pathology reports, and postoperative clinic notes were also reviewed.

Results: There were a total of 46 cases. There were 41 males and 5 females. The majority of pcSCC were located on the ear pinna (47%), followed by temple (13%), and scalp (5%). Patients with WPOI 4/5 were more likely to have received prior adjuvant treatment after initial excision of their primary (p = 0.035). 54.3% of cases had perineural invasion (PNI). 30.4% had positive margins. Histologically, most (71.1%) were infiltrative with a median WPOI score of 3. When comparing patients who had recurrence and those who did not, PNI was the only statistically significant histological factor and was associated with a higher rate of recurrence (p=0.036). Also, univariate logistic regression showed that patients with PNI were more likely to have recurrence than those who did not (HR 5.34, p=0.049).

Conclusions: Understanding how pcSCC with metastasis to the parotid behaves pathologically is important when determining prognosis. Our study is the first to our knowledge to show that PNI in metastatic pcSCC to the parotid is associated with higher recurrence rates. This suggests that PNI is important to consider even in patients with metastatic pcSCC as it can be an indicator of increased risk of recurrence and poor prognosis.

Presenting Author(s)

Mayuri A. Yasuda, MD

Resident
Loyola University Medical Center
Chicago, IL, United States

Disclosure(s):
faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.

Author(s)

AR

Aayushma Regmi, MBBS

Loyola University Medical Center, United States

Disclosure information not submitted.
CL

Cullen Lilley, MD

University of California Los Angeles, United States

Disclosure information not submitted.
MM

Maitri Mehta, DO

Loyola University Medical Center, United States

Disclosure information not submitted.
Eric J. Thorpe, MD

Chairman
Loyola University
Maywood, IL, United States

Disclosure(s):
faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.
SM

Swati Mehrotra, MD

Staff Pathologist and Director of Cytology
Edward Hines Jr. Veterans Administration Hospital
Hines, IL, United States

Disclosure(s):
faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.
AZ

Andrea M. Ziegler, MD

Assistant Professor
Loyola University Medical Center
Maywood, Illinois, United States

Disclosure(s):
faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.

Senior Author(s)

VA

Vijayalakshmi Ananthanarayanan, MD

Director of Anatomic Pathology
University of Illinois at Chicago
Chicago, IL, United States

Disclosure information not submitted.