Histologically Benign Pleomorphic Adenoma of Parotid with Subcutaneous Metastases

Abstract

P leomorphic adenoma is a benign salivary gland with potential for malignant transformation. When the malignant transformation occurs, the tumor develops a tendency for local recurrence and distant metastases and the histology of the tumor reflects all the cellular features of malignancy. However, there is an entity of pleomorphic adenoma which, while retaining benign histological features, tends to develop both local and distant recurrences despite adequate clearance at primary surgery. The reason for this remains unexplained and there is no predictor for this behavior. The rarity of its occurrence and inadequacy of information about its treatment prompted us to report our experience with one such case.

Cutaneous Metastasis From Parotid Tumors: A Report of 2 Cases and Literature Review

“…Including our cases, to the best of our knowledge, there have been only 44 reported parotid neoplasm cases with cutaneous metastasis in the English literature (Table 1). 9–48 In this review, most patients were men (66%), with a mean age at diagnosis or appearance of parotid neoplasm of 49.2 years, which is similar to parotid carcinomas epidemiology. 1…”

“…However, most authors agree that surgery is the treatment of choice, when feasible. 22,24 Adjuvant radiotherapy has been used mainly to treat local recurrence with or without chemotherapy for locally advanced disease. 56 Chemotherapy may be used in cases with no response or as a palliative treatment.…”

“…56 Among patients without a lymph node or distant metastasis (10 cases), 45.5% presented with skin metastasis exclusively on the head, which might be considered "regional spread." 18,19,22,27,39 Because cutaneous metastasis from parotid carcinomas is infrequent, there are no recommended treatment protocols. However, most authors agree that surgery is the treatment of choice, when feasible.…”

“…This finding is consistent with other reports of distant metastasis from parotid carcinoma (15 months). 56 Among patients without a lymph node or distant metastasis (10 cases), 45.5% presented with skin metastasis exclusively on the head, which might be considered “regional spread.” 18,19,22,27,39…”

“…According to a PubMed and Ovid database search, only 42 cases of cutaneous metastases from parotid neoplasms have been reported since 1956 (search date January 1, 1956, to July 31, 2020). 9–48 We describe 2 cases of parotid malignancies with cutaneous metastasis and a literature review of cutaneous metastasis from parotid tumors.…”