Concerned about skin cancer, a 70-year-old woman presents to dermatology for evaluation. She spent a great deal of time in the sun when she was younger and didn’t tolerate it well, although she has never received a diagnosis of skin cancer.

The examination uncovers no worrisome lesions in that regard, but several other long-standing findings are noted. On the patient’s right arm, many clear, firm intradermal nodules and freckles are evident.

The patient’s history includes several benign but troublesome tumors—among them, a pheochromocytoma and a brain tumor that required surgery. She has also had seizures (now controlled with medication) and hypertension (which resolved with the removal of her pheochromocytoma). No one else in her family, including her grown children, has experienced a similar skin condition.

ANSWER
The correct answer is neurofibromatosis type 1 (NF1; choice “a”), formerly known by its eponymic designation von Recklinghausen’s disease. NF1 is by far the more common of the two types; the second, NF2 (choice “b”), is characterized by acoustic neuromas. This patient’s freckling and obvious skin tumors are indicative of NF1, which develops from a spontaneously occurring chromosomal anomaly. Tuberous sclerosis (choice “c”) is also a genodermatosis, but it has markedly different findings and presentation from NF1. Albright’s syndrome (choice “d”) involves depigmentation but is otherwise quite different from NF1.

DISCUSSION
This woman, like most patients, was well aware of the manifestations of her disease. However, patients with NF1 often are encountered before they are officially diagnosed; it is therefore essential to examine and counsel them about the current nature of their condition as well as the likelihood that they will develop any of a variety of tumors. They also need education about the possibility that their neurofibromas will reach a size large enough to interfere with patients’ normal growth and development—occasionally to a serious degree.