Large, Nodulocystic Acneiform Eruption Following Radiotherapy for a Squamous Cell Carcinoma Recurrence in the Cervical Lymphatics

Zachary Hopkins, Benjamin L Witt, Marcus M Monroe, Glen M Bowen, Anneli R Bowen and Shane Lloyd

Background: This case involves an 86-year old man who originally presented with a nodal recurrence from a left-sided oral tongue squamous cell carcinoma. Incidentally, he also had a synchronous epidermal inclusion cyst in the posterior neck. Treatment involved surgical removal of the recurrent cancer and the cyst followed by the delivery of 66 Gy of radiation to involved areas. Post-radiation therapy the patient reported a large oozing lesion on his posterior neck. After treatment with doxycycline and prednisone the lesion resolved. Main Observations: Visually the lesion resembled a dermal lymphatic malignant recurrence. Pathologic analysis of the lesion showed no malignancy but was representative of an inflamed epidermal inclusion cyst versus an acneiform eruption. Since the lesion resolved with doxycycline and prednisone, acneiform eruption was felt to be more likely. Conclusions: The authors hypothesize that this lesion occurred via a similar mechanism as radiation dermatitis. Importantly, the unique exaggerated presentation of this case suggests that radiation can trigger an inflammatory response in areas of pre-existent cystic rupture leading to an acneiform nodulocystic eruption that can mimic dermal lymphatic recurrence of carcinoma.