Two cases of dermatoses koebnerizing within fields of previous radiotherapy

Radiotherapy-Associated Cutaneous Mastocytosis in a Patient With Breast Carcinoma. Case Report and Review of the Literature

ABSTRACT

Mast cell skin disease is rarely described after external beam radiation therapy in patients with breast carcinoma, with only 7 previous reports in the literature. Skin changes typically occur within (but are not limited to) the radiation field. We present a 64-year-old woman with postradiotherapy cutaneous mastocytosis on the left breast and adjacent chest wall. The clinical and laboratory findings in all reported patients, including the current case, are reviewed. No clear mechanism has been presented to explain disease pathogenesis; although, mast cell accumulation secondary to local mediators produced in response to radiation damage and/or koebnerization phenomenon have been proposed. Cutaneous/systemic mastocytosis is not widely recognized and may be underdiagnosed in the setting of postradiation for breast cancer. It is important for clinicians and pathologists to be aware of this diagnosis for patients presenting with rashes after radiotherapy.

Bullous morphoea: a retrospective study

Bullous morphoea is a rare variant of localized scleroderma whose pathogenesis has been widely discussed. We retrospectively reviewed the records of all histopathologically confirmed cases of morphoea followed from 2005 to 2015 at the Dermatology Clinic and Pathology Institute of the University of Cagliari, Sardinia, Italy. Among 137 patients with morphoea, 2 cases of the bullous variant were identified, which were successfully treated with methotrexate. Thus, the bullous form comprised 1.4% of all cases of morphoea, which is much lower than the 7.5% previously reported. In one of the cases, histopathological examination revealed a peculiar 'stretching' pattern of basal keratinocytes attached to the epidermal roof of the bulla, together with increased lymphatic vessels, which were either collapsed or dilated, stressing the role of lymphatics and possibly of excessive skin trauma and friction in the development of bullous lesions.

[Uncommon dermatologic disorders triggered by radiation therapy of breast cancer: A case-series]

Radiotherapy's main skin toxicities are now well-separated, acute (acute radiation dermatitis) or chronic complications (chronic radiation dermatitis, induced cutaneous carcinoma, aesthetic sequelae). Exceptionally, radiotherapy may induce, by isomorphic reaction or Koebner's phenomenon, some specific dermatosis. In this article, we report five new observations of these unusual complications of radiation therapy, occurring in very variable time after breast irradiation and remaining strictly localized in the irradiated field (cutaneous mastocytosis, Sweet syndrome, lichen planus, vitiligo). These cases emphasize the need to realize a systematic histological exam if any atypical skin lesion appears after radiotherapy, even long after.