Pseudolymphoma presents as leonine facies

Newport Beach, Calif. - A rare instance of cutaneous pseudolymphoma presenting as leonine facies was recently diagnosed in Southern California and treated successfully with a prolonged prednisone taper, says Rebecca Scudiero, M.D., a resident in the division of dermatology, David Geffen School of Medicine, UCLA.

Dr. Scudiero presented the case at the 57th Annual Meeting of the Pacific Dermatologic Association and noted that a review of the literature revealed only one other case of pseudolymphoma presenting as leonine facies. That case was reported in Archives of Dermatology in 1994.

The patient that Dr. Scudiero describes, a 41-year-old black woman, had a two-year history of enlarging facial nodules with loss of eyebrows, which developed into leonine facies. Her disease appeared to be idiopathic, as she had no other medical conditions, no family history of skin diseases, was not taking any prescription or over the counter medications or herbal supplements and had not traveled outside the country.

"Immunohistochemistry of the tissue was the key to the diagnosis," Dr. Scudiero says. "It showed that both B and T cells were present, represented by CD20 positivity and CD3 positivity. There was no light chain restriction: both kappa and lambda light chains were present, showing that there was a diverse population of B cells," she says.

Certain markers are expected in a lymphoid follicle, and the patient's were in the right locations rather than spread throughout the lesion, Dr. Scudiero adds. BCL-2 was positive on the mantle zone, and CD10 and BCL-6 were positive on the follicular center.

These tests were sufficient to make the diagnosis of cutaneous pseudolymphoma rather than lymphoma.

Although it was not done in this instance, a polymerase chain reaction can also be used to check for clonality of the cells involved and support the diagnosis, Dr. Scudiero says.

"We already knew the patient had both B and T cells, but we could have looked at those to see if there was one clone of B cells predominating."

"We typically think of a monoclonal gene rearrangement as supporting a diagnosis of lymphoma, but up to one-third of cases of pseudolymphoma can show this monoclonal gene rearrangement, and conversely, a polyclonal gene rearrangement usually would support a diagnosis of pseudolymphoma. But then in lymphomas, up to only two-thirds of cases will show the monoclonal rearrangement, so this is a hard diagnosis to make," she says.

Most cases of cutaneous pseudolymphoma are idiopathic, such as the one Dr. Scudiero describes, and this often makes them harder to treat. This case was exceptional for its strong response to oral steroids.

Known causes of pseudolymphoma include insect bites, Borrelia burgdorferi, secondary syphilis, trauma, post-zoster scars, vaccinations, injections, acupuncture, earrings and red tattoos.

For more information: Stein L, Lowe L, Fivenson D. Coalescing violaceous plaques forming leonine facies. Lymphocytoma cutis (pseudolymphoma). Arch Dermatol. 1994; 130: 1552-1553.