Relevance of Intraparotid Metastases in Head and Neck Skin Squamous Cell Carcinoma

Abstract

Objectives: Parotid lymph node metastases are common in head and neck cutaneous squamous cell carcinoma (cSCCHN). Here we evaluate the diagnostic, prognostic, and therapeutic implications of intraglandular lymph node (IGLN) metastases in cSCCHN. Study Design: Retrospective study in a tertiary referral university cancer institute. Methods: We included patients with cSCCHN who underwent parotidectomy and neck dissection (ND), with or without synchronous resection of the skin primary, between January 1999 and January 2018. The characteristics of cSCCHN with or without IGLN involvement were compared. Results: Altogether, 68 patients were included. Of the 29 (42.6%) patients classified as cN0, eight were upstaged pN+ and had concomitant IGLN involvement. Of 21 patients with pN0 disease, IGLN metastases were absent in only three cases, resulting in a specificity and sensitivity of parotid metastases to diagnose occult nodal neck metastases of 14.29% and 100%, respectively. The positive and negative predictive values were 14.29% and 100%, respectively. Univariate analyses only displayed a significantly higher rate of moderately and poorly differentiated primaries in patients with IGLN metastases (P = .015). Only advanced T-stages were significantly associated with neck recurrences. Conclusion: IGLN status in advanced cSCCHN is potentially predictive for occul nodal neck metastases. Our results suggest that ND in patients with histopathologically negative IGLNs and clinically negative neck lymph nodes may not be necessary given the high negative predictive value of IGLN status in this group of patients. Therefore, accurate diagnostic evaluation of IGLN involvement is mandatory.

Elective parotidectomy and neck dissection are not beneficial in cutaneous squamous cell carcinoma of the head

“…Dür detected occult metastases in parotis in 2 cases, however, subclinical neck metastases were not demonstrated in any case. 26 Sweeney found occult nodal involvement in only 5% of cases in which the result of elective parotidectomy was negative. 27 Both authors, like us, are therefore of the opinion that elective neck dissection of neck LNs is not indicated in patients in whom microscopic parotid metastases have been excluded.…”

“…However, this procedure is justified when parotid metastases are detected, as in these cases subclinical neck metastases occur in 20%‒80%. 24 , 26 , 28 …”

Parotid Gland Metastases of Cutaneous Squamous Cell Carcinoma of the Head: Occult Metastases Occurrence and Their Late Manifestation

“…In contrast, the Dur's [ 18 ] study indicates a 28% incidence of deep lobe metastases (with 5% isolated in the deep lobe only) supporting the indication for more extensive resection. This is also supported by the Thom's study [ 19 ], in which a set of 42 patients with metastatic superficial lobe involvement after total parotidectomy with neck dissection were detected with occult metastases in the deep lobe in 26% and in the cervical lymph nodes in 31% (in most cases, there were occult metastases detected simultaneously at both sites).…”

“…The questions remain whether adjuvant radiotherapy in this indication would be sufficient to cure any deep lobe micrometastases [ 18 , 37 ] and if superficial parotidectomy can be considered a sufficiently radical procedure.…”

“…Another negative factor appears to be the fact that despite the known predictive, NCCN [ 3 ] defined factors of lymphogenic manifestation of cSCC of the head, preventive cervical dissection or parotidectomy are currently not indicated. For patients with clinically present parotid metastases, surgical management and adjuvant radiotherapy, including cervical lymph nodes dissection, are indicated, even in cN0 necks [ 18 , 19 ]. Neck dissection in these cases has an elective character and is carried out selectively at levels consistent with the location of the primary tumour, e.g., neck level II, III, and possibly also level V for skin tumours of posterior scalp.…”