A 73－year－old female with multiple nodules on her back visited our department. She had a giant pigment nevus on her back since birth and was treated with cryotherapy using the carbon dioxide snow freezing method once or twice a week until she was 10 years old. About 3 years ago, an itchy rash appeared on her back, and the rash did not respond to treatment with a topical ointment containing purified white sugar and povidone－iodine. A well－defined grayish blue to brown pigmented macule of about 50 cm in size was observed from the back to the waist, with scattered white－toned scars, four nodules, and two erythemas on the macule. One nodule was 5 cm in size with an elevated margin and an ulcer at its center, two nodules were 2 cm, flattened, and raised, with margins bordered by dotted black spots, and one nodule was 2 mm and dark brown ; all were typical basal cell carcinomas in pathology. In addition, there was one erythema that was round and slightly scaly, and another that was irregularly－shaped and scaly ; both were Bowen’s disease in pathology. All tumors were excised and were negative for margins, and no recurrence was observed at 6 months. Although 18 cutaneous tumors that occurred after treatment with the carbon dioxide snow freezing method have been reported previously, there have been no reports of coexisting basal cell carcinomas and Bowen’s diseases.[Skin Cancer (Japan) 2023 ; 38 : 130－135]

A 30－year－old woman with a history of chest pain and loss of appetite was referred to our hospital for evaluation of severe anemia and a large mass on the right upper back for 3 years prior to presentation. The patient was severely emaciated, with a body mass index (BMI) of 14.7 kg/m², and blood test results showed a serum hemoglobin level of 2.7 g/dL. The tumor measured 20×10×7 cm and was partially exposed as a calcification with ulceration.

Based on biopsy and ultrasonography findings, we diagnosed the patient with a pilomatricoma. Blood transfusion improved the patient’s anemia ; however, we observed an increase in the size of the mass and bleeding from the ulcer. Therefore, we performed transcatheter arterial embolization before resection under general anesthesia, and the tumor was diagnosed as a pilomatricoma. Anemia improved 3 months postoperatively, and the BMI returned to the normal range after 4 months. No recurrence was observed at 8－month follow－up.[Skin Cancer (Japan) 2023 ; 38 : 136－141]

A 77－year－old man who developed multiple nodules on his head visited a local physician, and a biopsy of one of the lesions showed cutaneous angiosarcoma. Computed tomography scan revealed numerous swollen lymph nodes extending from the left neck to the supraclavicular fossa. The patient received six doses of paclitaxel, but he developed numbness in his fingers and declined continuation of the treatment. Cancer multigene panel testing showed that the tumor mutational burden was high (31 Muts/Mb). We determined that pembrolizumab was indicated for this cutaneous angiosarcoma with a high tumor mutational burden because continuation of standard therapy was difficult. After receiving two doses of pembrolizumab (200 mg every 3 weeks), the treatment was discontinued because the patient found it difficult to frequently visit our hospital. However, 6 months after discontinuation, the tumor on his head disappeared and the lymphadenopathy in his neck continued to shrink.[Skin Cancer (Japan) 2023 ; 38 : 142－147]

Case 1 : A 79－year－old Japanese woman noticed a nodule on her right posterior auricle more than 4 years ago which gradually increased in size. A physical examination showed a pedunculated mass arising from a yellowish－white verrucous plaque on her right posterior auricle. Histologically, the mass and the verrucous plaque corresponded to sebaceous carcinoma and sebaceous nevus, respectively.

Case 2 : A 70－year－old Japanese woman with a congenital verrucous plaque on her right cheek noticed a nodule developing on the plaque about a year ago. Total resection of the lesions revealed that the nodule and the verrucous plaque corresponded to sebaceous carcinoma and sebaceous nevus, respectively.

Among the 91 patients with sebaceous nevus that were histologically diagnosed in our department, 14 developed secondary skin tumors, 50% of which were malignant. Therefore, we conclude that dermatologists should inform patients with sebaceous nevus that such skin lesions may become malignant over time.[Skin Cancer (Japan) 2023 ; 38 : 148－153]