To the Editor: A 72-year-old woman underwent radical excision of an adenocarcinoma of the right nasolacrimal duct. Postoperative radiation therapy (30 Gy) was added to the residual tumor, which, however, it was insufficient, and the tumor persisted at the external base of the skull. During admission, she was referred to our department complaining of a nodule on the abdomen. Physical examination showed a 5-mm-sized reddish nodule with erosion of the surface (Fig. 1A). A skin biopsy showed tumor nests connecting to the epidermis and extending downwards into the dermis (Fig. 1B). High-power magnification revealed small uniformly cuboidal cells with round deeply basophilic nuclei, which were connected by intercellular bridges. A few cystic or ductal structures were identified within the nests. Immunohistological examination showed strong expression of carcinoembryonic acid in the duct wall, and poroid cells were positive for epithelial membrane antigen. Gross cystic disease fluid protein-15 (GCDFP-15) was negative. Further clinical examination revealed additional reddish nodules on the trunk, neck, and extremities (Figs. 2A, B), which summed up to 10 in total. She complained that those nodules were increased in number after radiation therapy. All of them were surgically removed under local anesthesia. Histological examination revealed that all of them were compatible with the features of poroma. Histological examination showed anastomosing lobules of nests consisting of small, uniform, basophilic, and cuboidal poroid cells. Scattered ductal structures surrounded by the eosinophilic cuticular cells were also recognized. Notably, some of the poromas showed that the tumor nests were confined to the epidermis, indicating intraepidermal poroma (Fig. 2C). In contrast, others were those of Pinkus type. The tumor nests were surrounded with myxomatous stroma, which were highlighted by Alcian blue stain (Fig. 2D). Findings of peripheral palisading were absent in all the basophilic tumor islands.FIGURE 1: A reddish nodule on the chest (arrow). A, Surrounding erythema is allergic contact dermatitis due to adhesive tape. B, Histological features showing anastomosing lobules of tumor nests consisting of poroid cells.FIGURE 2: A and B, Reddish small nodules are scattered on the chest, neck, shoulders, and other areas on the trunk. C, Tumor nests were confined within the epidermis in some lesions. D, Tumor nests in the dermis were surrounded by myxomatous stroma, which was positively stained by Alcian blue stain.The most interesting feature in our case is the multiple occurrences of poromas after radiation therapy in a cancer-bearing patient. Poroma usually occurs as a solitary lesion or at most a few lesions. So far, several cases of multiple eccrine poromas have been reported, most of them occurred in patients with malignancies (Table 1).2–7 In particular, hematologic malignancies such as lymphoma or leukemia have been seen.6,7 In other cases, poromas arised on the irradiated sites5–7 or occur following chemotherapies.7 Our case rapidly developed multiple poromas after radiation therapy, although the occurrence sites were not the irradiated sites. In addition to hematologic malignancies, there also reports of poromas developing after bone marrow transplantation and subsequent graft versus host disease.7 Our case presented with not hematologic malignancy but invasive solid cancer. There was no evidence of either lymph node or distant metastases. The development of multiple poromas may be secondary to immunosupression.TABLE 1: Multiple Eccrine PoromasAnother interesting point was that the poromas exhibited different histological patterns, although presented similar clinical features. Some of them showed the features of common Pinkus type, while the others showed intraepithelial nests, namely intraepidermal poromas. The behavior of all the resected poromas was benign. Additionally, the stroma surrounding the poroma nests was myxomatous in some of the lesions showing mucin deposition which was highlighted by Alcian blue stain. Mucinous stroma is not a common finding in poromas. In conclusion, we report a case of multiple poromas in a patient with invasive carcinoma. The patient was not treated with chemotherapy, but eruptive poromas occurred after radiation therapy. The occurrence of multiple poromas may be related to immunosupression.