MUNICH - While primary cutaneous B-cell lymphomas must be clearly separated from non-Hodgkin's B-cell lymphomas with secondary cutaneous involvement and from cutaneous B-cell pseudolymphomas, "from the truly clinical and prognostic point of view, low-grade lymphomas are one disease," according to Nicola Pimpinelli, M.D., at the annual meeting of the European Academy of Dermatology
and Venereology. "In our experience," said Dr. Pimpinelli, associate professor of dermatology, department of dermatological sciences, University of Florence Medical School, Italy, "the identification of distinct subgroups is disputable from a strictly histologic, immunophenotypic, and genotypic point of view, and has no correlation with either the clinical course or the prognosis of the disease."He
added that the large majority of CBCL show a uniform immunophenotype (CD5-, CD10-) and genotype (lack of bcl-1/bcl-2 and c-myc gene rearrangement) of neoplastic cells.
According to the EORTC classification of primary cutaneous lymphomas, CBCL with indolent behavior are divided into two subgroups, Dr. Pimpinelli
explained.These subgroups are the follicular center cell lymphoma and the immunocytoma/marginal zone lymphoma.They are named due to putative histologic similarities with their purported nodal counterparts.
"Generally speaking, more than 90 percent of primary cutaneous B-cell lymphoma have a very good prognosis, independent of their histologic categorization," Dr. Pimpinelli
said.Whatever the subgroup, he
added, the large majority of CBCL are characterized by a homogeneous clinical presentation and behavior, they have a good response to local radiotherapy, a low tendency to extracutaneous spread, and they have an excellent prognosis."
In a series of patients, local orthovolt radiotherapy produced a complete remission in 98.2 percent of 115 patients treated, Dr. Pimpinelli
"Very often, in the same patient at different time points or even contemporaneously, you can find lesions in which you can make two different diagnoses, follicular center cells in one lesion and marginal zone lymphoma in another," Dr. Pimpinelli
Histological (left), and immunohistochemical views.
"No matter if you classify them as follicular center cell lymphoma or marginal zone lymphoma, which are two different subtypes of histologic diagnoses, the clinical appearance, and more important, the clinical outcome, of the disease is exactly the same," he
said.These lesions can be treated with surgery if they are isolated, or with radiotherapy, if they are grouped.
"A further matter of debate is whether the rare, so-called large B-cell lymphoma of the leg - the third subgroup of primary CBCL identified in the EORTC classification - should indeed be regarded as a distinct clinicopathologic entity," Dr. Pimpinelli
These patients seem to have an intermediate prognosis, Dr. Pimpinelli
said.It is clear that these patients have lesions mostly localized on the legs, with de novo large cell (centroblast-like or immunoblast-like) histology, and they are very often older than 70.This makes it difficult to treat these patients long term."In fact, sometimes radiotherapy gives some very good results, but you can have very quick relapses and you are concerned to treat them again with radiotherapy because of problems of cumulative dosage.On the other hand, effective chemotherapy cannot be reasonably proposed due to a the old age of these patients."Care for these patients, who are sometimes 75 to 80 years old, can be therefore a problem from a management point of view."The prognosis of these patient is heavily conditioned from the age of the patients," Dr. Pimpinelli
For more information
Pimpinelli N, Santucci M. The skin-associated lymphoid tissue-related B-cell lymphomas.Semin Cutan Med Surg.2000 Jun;19(2):124-129.