Fingertip cutaneous metastasis of salivary duct carcinoma secondary to scald: A unique case report and a brief review of literature (following CARE guidelines)

Rationale:Salivary duct carcinoma (SDC) is an aggressive form of cancer, with cutaneous metastasis being a rare occurrence. Furthermore, cutaneous metastasis of SDC secondary to a scald is even rarer, and to the best of our knowledge, our case represents the first such instance. Considering the involvement of the fingers in the metastatic site, which may affect limb function and quality of life, we present this case to explore the reason why scald could lead to distant recurrence and better treatment options.Patient concerns:An 85-year-old man diagnosed with SDC in the parotid gland found enlarged masses at the fingertips as a consequence of a burn, 6 years after his initial treatment.Diagnoses:Cutaneous metastasis of SDC in the parotid gland and left thumb loss due to surgery.Interventions:Radiotherapy was offered, targeting at the masses on the fingers, with dose at 15 Gy in 3 fractions, 12 Gy in 3 fractions, 15 Gy in 3 fractions for both hands and additional 21 Gy in 7 fractions only for left hand.Outcomes:The tumors shrank after 2 months of radiotherapy and the patient recovered well. Side effects included nail hyperplasia and paronychia.Lessons:Connections between scald and distant metastasis of malignant tumors in this case needed further investigation. Considering reserving function of the fingers while dealing with metastasis, radiotherapy is recommended rather than surgery.