Unexpected Detection of Parotid Gland Malignancy during Primary Extracapsular Dissection

Abstract

Objective. To evaluate the oncologic and functional outcome in cases in which a false preoperative working hypothesis ''benign parotid tumor'' led to a primary extracapsular dissection being performed rather than a traditional, more radical surgical modality.Study Design. Case series with chart review.Setting. Academic tertiary referral center.Subjects and Methods. The records of all patients treated for malignant tumors of the parotid gland between 2006 and 2012 were retrospectively studied. Patients were excluded from our study sample for insufficient data or if their histories indicated manifestation of malignant tumors without primary parotid origin (squamous cell carcinomas, lymphomas, melanomas), revision surgery, as well as concomitant or past malignant tumors. Consequently, a total of 29 patients with 30 primary malignant tumors of the parotid gland formed our study sample (14 men, 15 women; male:-female ratio, 0.93:1; mean age, 55.4 years; range, 14-85 years).Results. Of 30 cases, 22 had low-grade tumors. Further tumor cells were detected in only the histology specimens of the parotid in 3 of the 25 cases treated subsequently with completion parotidectomy. Five patients received adjuvant radiation. Five-year disease-specific survival was 100%; local disease control was 96.6%. Of 30 cases, 28 had HouseBrackmann I after tumor treatment; the other 2 cases had a slight paralysis (House-Brackmann II). Conclusion.Beginning with the ''false'' working hypothesis and performing an extracapsular dissection in unsuspected cases seems to have no adverse impact on patients' survival and postoperative quality of life in cases in which definitive histology reveals malignancy.

Incompletely treated malignancies of the major salivary gland: Toward evidence‐based care

“…Although there was no difference in 10‐year disease‐specific survival, this study was not powered to demonstrate noninferiority between the treatment methods. Mantsopoulos et al reported 29 patients who underwent extracapsular dissection in unexpected parotid tumors. Five‐year OS was 100% and local disease control was 96.6%.…”

“…Variability in preoperative evaluation and diagnostic sensitivity of FNA may lead to encountering malignancy intraoperatively when benign pathology was anticipated. In cases in which the index of suspicion is low for malignancy, patients may receive more conservative surgery compared to the extent of dissection required for known malignancy . Two small case series consisting of patients with unexpected parotid gland malignancies demonstrated that more conservative surgery may be adequate .…”

Investigation of arguments against properly indicated extracapsular dissection in the parotid gland

“…A final potential argument against extracapsular dissection is that it might have an adverse effect on the course of cases in which definitive histology reveals unexpected malignancy. A study of the relevant literature shows that unexpected malignancy on definitive histology after minimal invasive surgical modalities (extracapsular dissection) on the parotid gland appears in 3.4% to 4.8% of cases . Interestingly, a literature report of the same working group demonstrated consistently acceptable functional and oncologic results after primary extracapsular dissection in such cases .…”

“…Extracapsular dissection was defined as meticulous dissection around the tumor capsule and tumor extirpation with a layer of healthy tissue without the intention to preidentify or expose the main trunk or branches of the facial nerves . This modality was indicated in solitary and mobile tumors located within the lateral lobe of the parotid gland with preoperative clinical and imaging signs of benign tumor.…”

“…Extracapsular dissection was defined as meticulous dissection around the tumor capsule and tumor extirpation with a layer of healthy tissue without the intention to preidentify or expose the main trunk or branches of the facial nerves. 1,6 This modality was indicated in solitary and mobile tumors located within the lateral lobe of the parotid gland with preoperative clinical and imaging signs of benign tumor. Furthermore, this modality was performed in tumors arising from the pharyngeal prolongation of the parotid gland and located in the deep parapharyngeal space via extended submandibular incision, after sectioning of the posterior belly of the digastric muscle and the styloid process.…”