Bilateral Axillary Basal Cell Carcinoma

Dear Editor, Basal cell carcinomas (BCCs) most frequently involve sun-exposed areas such as the face, but other regions including the trunk and extremities are rarely affected. Although BCCs can occur on the axilla, bilateral onset is rare. We describe a rare case of BCCs that developed in both axillae and on the face. An 80-year-old woman visited our department with lesions in both axillae that had appeared two years earlier. She had a previous history of uterine sarcoma that had been treated with radiotherapy. However, she denied any history of irradiation or trauma to the axillae. Physical examination showed blackish nodules in both axillae [Figure 1a and b]. Close-up view showed a well-circumscribed blackish nodule in right axilla [Figure 1c], and an ulcerated blackish nodule in the left axilla [Figure 1d]. Lymphadenopathy was not observed. Laboratory examination results were normal, except for increased levels of creatinine (1.65 mg/dL) and blood urea nitrogen (28 mg/dL). Dermoscopic examination of the axillary nodules showed large blue-grey ovoid nests and arborising vessels in both lesions [Figure 1e and f], suggestive of BCC. Biopsy revealed basaloid tumour islands with peripheral palisading and surrounding mucinous stroma in both of the lesions [Figure 1g and h]. Upon admission to our department, a detailed examination revealed a blackish erosive nodule on the face [Figure 1i], which histopathologically showed a number of small basaloid tumour islands in the dermis [Figure 1j], compatible with BCC. The three lesions were completely excised with a 5-mm margin under local anaesthesia. At the time of writing, the patient has experienced no recurrence over a follow-up period of two years and six months.Figure 1: Blackish nodule in both axillae (a, b). Close-up view showed a well-circumscribed blackish nodule in the right axilla (c) and an ulcerative blackish nodule in the left axilla (d). Dermoscopic examination (contact dermoscopy, polarized mode) of the axillary nodules showed large blue-grey ovoid nests and arborising vessels in both lesions (e, f). Histological features showing basaloid tumor islands with peripheral palisading and surrounding mucinous stroma in both lesions (g, h) (H&E,40x). A blackish erosive nodule on the adjacent nasal root (i). Histological features showing a number of small basaloid tumor islands in the dermis (j) (H&E,40x)BCCs frequently occur on sun-exposed areas of the body. On the other hand, approximately 10–15% of BCCs develop on sun-protected areas, including the axillae, breasts, perianal area, genitalia, palms, and soles.[1] According to previous studies, axillary BCCs account for 0.15% to 1.8% of all BCC cases.[2] To the best of our knowledge, there have been only four reported cases of BCCs in both axillae, including the present case.[2] One of the patients was reported to have basal cell nevus syndrome. Our patient did not develop numerous early onset BCCs or other characteristic cutaneous and skeletal features including odontogenic keratocysts and palmoplantar pits. Also, her BCCs were limited to three, and she had no family history of multiple BCCs. Therefore, we excluded basal cell nevus syndrome, although examination for gene mutations affecting Patched 1 (PTCH1), Patched 2 (PTCH2), or Suppressor of fused (SUFU) of the sonic hedgehog signalling pathway was not performed. A summary of the four cases is shown in Table 1.[3-5] The patients consisted of one male and three females, with a mean age of 62 years. One case was European (Italian), while the remaining three were Japanese.[2] The tumor size ranged from 6 mm to 34 mm, with a mean tumor size of 18 mm in the right axilla and 19 mm in the left axilla. The histological types were superficial (Case 1) and nodular (Cases 2, 3, and the present case). All four patients had brownish or blackish nodules, but the patient in the present report also had erosion and ulceration. Case 3 had basal cell nevus syndrome. These lesions in all cases were excised under local anesthesia. The present case developed BCCs not only in both axillae but also on the face, where histopathology revealed nodular (bilateral axillae) and micronodular (face) type BCCs. Although our patient had uterine sarcoma and had received radiation and chemotherapy, the total number of BCCs was only three. Therefore, we consider that the association between BCCs and uterine sarcoma is fortuitous, and it is unlikely that immunosuppression in this patient contributed to the bilateral axillary development with BCCs.Table 1: Summary of four cases of bilateral axillary onset BCCsDeclaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understands that her name and initials will not be published and due efforts will be made to conceal her identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.