No abstract

A 38‐year‐old Japanese male with Bloom's syndrome (BS) and porokeratosis of Mibeili (PM) developed multiple carcinomas of the skin and lung. There were multiple, spontaneous chromosomal aberrations and frequent sister chromatid exchanges (SCE). Cutaneous delayed‐type hypersensitivity reactions were defective and serum IgM was decreased. The lung cancer was treated with radiation, which was effective but caused a severe pulmonary atelectasis and esophageal stricture. The patient expired one‐and‐a‐half years later because of pneumonia. Autopsy disclosed an adenocarcinoma of the colon. The concurrent PM was considered responsible for the occurrence of multiple skin cancers.

A 49-year-old man with extensive porokeratosis of Mibelli (PM) developed a squamous cell carcinoma and several carcinomas-in-situ within the lesional skin. The patient also had diabetes mellitus and a short stature with a prematurely aged appearance. The patient's father and two siblings also had PM. The patient died from metastatic squamous cell carcinoma, and at autopsy an adenocarcinoma of the descending colon was also found. Fibroblasts cultured from both the PM-affected and unaffected skin showed chromosomal abnormalities and a decreased lifespan. Cellular sensitivity to ultraviolet rays measured by unscheduled DNA synthesis and colony-forming ability were within normal limits. An association with a forme fruste of Werner's syndrome was suspected.