This document contains two reports. In the first report a case of incontinentia pigmenti in a Japanese girl with associated retrolental mass is presented in conjunction with a review of the other known cases of this association in the literature. In the second report, the case of a 42-year-old female with a parathyroid cyst is presented. Review of the literature reveals 38 patients in whom the diagnosis of a parathyroid cyst was supported by the presence of parathyroid tissue within the cyst wall. Of these patients, 70% were women and half of them were less than 40 years old. More than 90% of the cysts are found in the region of the inferior parathyroid glands. The lesion may be associated with symptoms of pain, hoarseness, respiratory obstruction or, in 15% of the cases, with hyperparathyroidism. The cysts commonly increase rapidly in size, but may show periods of remission. It is proposed that these lesions occur more frequently than reports would indicate. It is also believed that the production of clinically significant parathyroid cysts is the result of retention of secretions. 43 references, 7 figures, 2 tables.