Primary cutaneous follicular lymphoma: an assessment of clinical, histopathologic, immunophenotypic, and molecular features.
OBJECTIVE
Unlike nodal follicular lymphoma (NFL), Primary cutaneous follicular lymphomas (PCFLs) rarely express Bcl-2 protein or t(14;18)(q32;q21) (Bcl-2/IgH). The aim of this study was to further characterize PCFL in a large series from North America.


METHODS
Clinical data and archival formalin-fixed, paraffin-embedded tissue were obtained from 32 patients. PCFL was defined as follicular lymphoma limited to the skin at the time of diagnosis and within the first 6 months after diagnosis. Specimens were analyzed for the expression of CD3, CD10, CD20, Bcl-2, and Bcl-6 proteins by immunohistochemistry as well as for the presence of t(14;18)(q32;q21) by polymerase chain reaction.


RESULTS
The male-to-female ratio was 1.5:1, with a median age of 60 years. Twenty-four patients had lesions on the head and neck, five had lesions on the trunk, and three had lesions on both head and trunk. Follow-up data were available in all cases, with a mean length of 35.8 months. The majority of the patients were treated with radiation therapy. All patients were alive at last follow-up except one. Recurrence was noted in seven patients (22%), after a mean disease-free survival time of 17.7 months. CD10 and Bcl-6 expression were seen in 29 (91%) of 32 and 31 (97%) of 32 cases, respectively. Bcl-2 expression was noted in 13 (41%) of 32 cases. PCR results for t(14;18)(q32;q21) were positive in 11 (34%) of 32 patients and showed correlation with Bcl-2 protein expression. The sequencing of the t(14;18)(q32;q21) amplicons confirmed unique breakpoints in each of the seven tested cases. Comparison between the Bcl-2 and/or t(14;18)(q32;q21)-positive and t(14;18)(q32;q21)-negative cases revealed no significant difference in age, site, clinical course, or outcome.


CONCLUSIONS
We demonstrated Bcl-2 protein expression and t(14;18)(q32;q21) in a significant minority of cases, suggesting a relationship with NFL. It remains to be seen whether, on longer follow-up, there is any clinical difference in cases with and without t(14;18)(q32;q21).
Mirza
I
I
Cleveland Clinic Foundation, Cleveland, OH 44195, USA.
Macpherson
N
N
Paproski
S
S
Gascoyne
R D
RD
Yang
B
B
Finn
W G
WG
Hsi
E D
ED
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018951:Antigens, CD20 / Q000032:analysis; D017252:CD3 Complex / Q000032:analysis; D002883:Chromosomes, Human, Pair 14; D002887:Chromosomes, Human, Pair 18; D004273:DNA, Neoplasm / Q000235:genetics; D004268:DNA-Binding Proteins / Q000032:analysis; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D016393:Lymphoma, B-Cell / Q000235:genetics / Q000276:immunology / Q000473:pathology*; D008224:Lymphoma, Follicular / Q000235:genetics / Q000276:immunology / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D015260:Neprilysin / Q000032:analysis; D016133:Polymerase Chain Reaction; D011518:Proto-Oncogene Proteins / Q000032:analysis; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000032:analysis; D051560:Proto-Oncogene Proteins c-bcl-6; D017422:Sequence Analysis, DNA; D012878:Skin Neoplasms / Q000235:genetics / Q000276:immunology / Q000473:pathology*; D014157:Transcription Factors / Q000032:analysis; D014178:Translocation, Genetic
D018951:Antigens, CD20; D017252:CD3 Complex; D004273:DNA, Neoplasm; D004268:DNA-Binding Proteins; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D051560:Proto-Oncogene Proteins c-bcl-6; D014157:Transcription Factors; D015260:Neprilysin