A 15-year-old male with a rare form of skin cancer saw a nodule on his left nasal wing shrink and flatten after doctors treated him with 60 Gy of electron beam radiation, Cureus reported.
The patient first noticed the lesion six months before seeking care and was referred for evaluation after it began enlarging. Examination revealed a 9 mm red nodule on the left nasal wing, Cureus reported. A biopsy showed atypical plasma cells in the dermis that were CD138-positive and demonstrated lambda light chain restriction, confirming a diagnosis of plasmacytoma. The patient had no significant past medical history, and CT and MRI scans showed no other lesions. The cells were negative for CD10 and CD20, and kappa light chain showed only minimal positivity.
Systemic testing found no M protein in blood or urine, normal calcium and kidney function, and a bone marrow plasma cell count of 1.8%, leading doctors to diagnose primary cutaneous plasmacytoma, an extremely rare condition with only about 80 cases reported to date, Cureus reported.
Doctors Increased Radiation Dose to 60 Gy
Because the lesion’s location on the nasal wing made surgical removal difficult, physicians planned radiation therapy using a 6 MeV electron beam, Cureus reported. The initial plan called for 50 Gy in 25 fractions, but when the tumor showed poor response at 46 Gy, doctors — after consulting with the patient and family — increased the total dose to 60 Gy delivered in 30 fractions.
Lesion Shrank from 9 mm to 7 mm
At the 60 Gy mark, the lesion had crusted over and shrunk to 7 mm, with mild dermatitis as the only side effect, Cureus reported. Seven months after treatment ended, the lesion had flattened and continued to shrink.
Condition Usually Affects Older Men
Primary cutaneous plasmacytoma typically occurs in elderly or middle-aged men and rarely affects young adults, Cureus reported. While radiation doses for this condition have ranged from 20 Gy to 50 Gy in previous cases, this 60 Gy dose represents the highest reported in the literature, according to the case report. Previous cases include a 2016 report of a 69-year-old man treated with 35 Gy in 10 fractions using Ortho-225 kVp voltage with no recurrence during 11 months of follow-up, and a 1977 report of a 52-year-old man treated with 48.18 Gy in 7 fractions using a mold containing a radon seed with no recurrence during 18 months.