Inflammatory seborrheic keratosis resolution after hyperbari
Seborrheic keratosis (SK) is a common epidermal tumor, consisting of a benign proliferation of immature keratinocytes. Clinically, SK manifests as solitary or multiple, well-demarcated brownish papules or plaques with a verrucous surface, that predominantly localizes at the head, neck, and trunk areas. Since the tumor slowly grows, in many cases the lesion is surgically removed due to cosmetic reasons or because the lesions are traumatized and become symptomatic.

A 74 years old man was admitted for HBOT due to chronic late post-radiation hemorrhagic cystitis (grade 3-4 RTOG). In addition, on his left temple, he had a slowly growing SK lesion, known for about 24 months prior to the treatment. The SK presented as a red non-tender demarcated lesion, 2.5 cm diameter in size, with clear boundaries and occasional mild oozing.

The lesion was diagnosed as inflammatory seborrheic keratosis and was scheduled for surgical removal after the intendent HBOT.

The medical history of the patient included prostate cancer (Glisson score 6), diagnosed 13 years prior to his admission, that was treated with radiation. Since he had chronic unremitting hemorrhagic cystitis, he was referred to HBOT. In addition to cystitis, he had type-II diabetes mellitus, hypertension, osteoporosis, gastroesophageal reflux, hyperlipidemia, s/p resection of craniopharyngioma, and a fractionated stereotactic radiation therapy, gait disturbance with parkinsonism, and a primary unspecified kidney tumor.

The HBOT protocol used for his hemorrhagic cystitis included a total of 56 hyperbaric sessions, five days per week of 90 minutes 100% oxygen at 2 ATA with five-minute air breaks every 20 minutes. The treatment went well with no significant side effects and the clinical symptoms of hemorrhagic cystitis resolved. Surprisingly, in addition to the resolution of cystitis, there was a full resolution of the 2.5 cm seborrheic keratosis lesion. During a follow-up, 16 weeks after the last hyperbaric session, the skin was still intact without any sign of recurrence.