Early Cutaneous Metastasis of Adenoid Cystic Carcinoma of the Salivary Gland
Adenoid cystic carcinoma (ACC) of the salivary glands is a malignant tumor characterized by slow but relentless progression that is plagued by local recurrence, late metastases, and ultimately fatal outcomes. Twenty-four percent to 52% of ACCs of the salivary glands result in distant metastasis, primarily involving the lungs, bones, liver, and brain. Cutaneous metastasis of these tumors is rare and usually represents an advanced stage of disseminated disease. We report the case of a 61-year-old man with a history of ACC of the right submandibular region who was referred to our dermatology clinic 2 months following wide excision of the tumor. A nonspecific dermatitis had developed at the surgical site. A skin biopsy was performed due to the discovery of eruptive papules on the scalp and neck, which demonstrated the characteristic histopathologic features of metastatic ACC. Our case underscores the importance of conducting a complete skin examination in oncologic patients, especially focusing on cutaneous and subcutaneous nodules and papules that are eruptive or show rapid development.
Conclusion
Cutaneous metastasis represents an important sign of disease progression, allowing for the early discovery of systemic diffusion of the tumor as well as adjustment of the therapeutic approach. Our patient not only highlights a rare case of cutaneous metastases in this type of tumor but also the importance of conducting complete skin examinations in oncologic patients. Even minor findings should not be ignored in this patient population. In fact, if correctly interpreted the early discovery of cutaneous metastasis in patients with salivary gland tumors may determine a dramatic change in diagnosis, prognosis, and treatment.
