title: In situ mantle cell lymphoma: clinical implications of an incidental finding with indolent clinical behavior.
abstract: BACKGROUND
  Cyclin D1-positive B cells are occasionally found in the mantle zones of reactive lymphoid follicles, a condition that has been called "in situ mantle cell lymphoma". The clinical significance of this lesion remains uncertain.
  
  
  METHODS
  The clinical and pathological characteristics, including SOX11 expression, of 23 cases initially diagnosed as in situ mantle cell lymphoma were studied.
  
  
  RESULTS
  Seventeen of the 23 cases fulfilled the criteria for in situ mantle cell lymphoma. In most cases, the lesions were incidental findings in reactive lymph nodes. The t(11;14) was detected in all eight cases examined. SOX11 was positive in seven of 16 cases (44%). Five cases were associated with other small B-cell lymphomas. In two cases, both SOX11-positive, the in situ mantle cell lymphoma lesions were discovered after the diagnosis of overt lymphoma; one 4 years earlier, and one 3 years later. Twelve of the remaining 15 patients had a follow-up of at least 1 year (median 2 years; range, 1-19.5), of whom 11 showed no evidence of progression, including seven who were not treated. Only one of 12 patients with an in situ mantle cell lymphoma lesion and no diagnosis of mantle cell lymphoma at the time developed an overt lymphoma, 4 years later; this case was also SOX11-positive. The six remaining cases were diagnosed as mantle cell lymphoma with a mantle zone pattern. Five were SOX11-positive and four of them were associated with lymphoma without a mantle zone pattern.
  
  
  CONCLUSIONS
  In situ mantle cell lymphoma lesions are usually an incidental finding with a very indolent behavior. These cases must be distinguished from mantle cell lymphoma with a mantle zone pattern and overt mantle cell lymphoma because they may not require therapeutic intervention.
authors: Hospital Clinic, IDIBAPS, University of Barcelona, Barcelona, Spain.
authors: Alejandra
authors: A
authors: Carvajal-Cuenca
authors: Luz F
authors: LF
authors: Sua
authors: Nhora M
authors: NM
authors: Silva
authors: Stefania
authors: S
authors: Pittaluga
authors: Cristina
authors: C
authors: Royo
authors: Joo Y
authors: JY
authors: Song
authors: Rachel L
authors: RL
authors: Sargent
authors: Blanca
authors: B
authors: Espinet
authors: Fina
authors: F
authors: Climent
authors: Samuel A
authors: SA
authors: Jacobs
authors: Jan
authors: J
authors: Delabie
authors: Kikkeri N
authors: KN
authors: Naresh
authors: Adam
authors: A
authors: Bagg
authors: Pierre
authors: P
authors: Brousset
authors: Roger A
authors: RA
authors: Warnke
authors: Sergi
authors: S
authors: Serrano
authors: Nancy Lee
authors: NL
authors: Harris
authors: Steven H
authors: SH
authors: Swerdlow
authors: Elaine S
authors: ES
authors: Jaffe
authors: Elías
authors: E
authors: Campo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D033162:Incidental Findings; D020522:Lymphoma, Mantle-Cell / Q000175:diagnosis* / Q000235:genetics / Q000628:therapy; D008297:Male; D008875:Middle Aged; D055751:SOXC Transcription Factors / Q000235:genetics
chemical_list: C097473:SOX11 protein, human; D055751:SOXC Transcription Factors