Primary Cutaneous B-Cell Lymphoma (PCBCL)

For cutaneous T-cell lymphomas, see Mycosis fungoides

Pathology

• B-cell lymphomas 20-25% of all cutaneous lymphomas
• Subtypes: primary cutaneous follicular center-cell lymphoma (PCFCCL), primary cutaneous immunocytoma (PCI), primary cutaneous large B-cell lymphoma (PCLBCL) of the leg

WHO Classification

• Most common histology: diffuse large B-cell lymphoma

EORTC Classification

• Note: in the EORTC, diffuse large B-cell lymphomas of non-leg site are classified as follicle center cell (i.e., considered indolent instead of aggressive)

Epidemiology

• Overall (data from SEER, PMID 15908651)
  • Mean age 64 yrs. Male 54%.
  • Incidence increasing
  • Histology (WHO): DLBCL in 33%, NOS 24%, follicular 17%, MZL 8%
  • Site: head or neck 50%, trunk 19%, arm 12%, leg 11%, disseminated 8%

• PCFCCL
  • Localized to skin; rarely disseminate to extracutaneous sites
  • Usually involve head or trunk
  • 5-yr OS > 95%
• PCI
  • Usually involve arms and legs
  • Excellent prognosis
• PCLBCLs of the leg
  • Affects elderly patients
  • More often involves extracutaneous sites
  • Poor prognosis: 5-yr OS 58%

• SEER; 2008 (1973-2004) PMID 18349400 -- "Analysis of primary CD30+ cutaneous lymphoproliferative disease and survival from the Surveillance, Epidemiology, and End Results database." (Yu JB, J Clin Oncol. 2008 Mar 20;26(9):1483-8.)
  • SEER review. 268 cases; 58% males, 87% white. 157 (59%) primary localized PCLPD
  • Outcome: 3-year OS 81% vs. population-matched OS 87%; 5-year DSS 92%. H&N worse outcome
  • Conclusion: Rare disease, with excellent OS; more common in white men, H&N sites worse survival

Prognostic Index

• Yale; 2005 - PMID 15908651 — "The cutaneous B-cell lymphoma prognostic index: a novel prognostic index derived from a population-based registry." (Smith BD, J Clin Oncol. 2005 May 20;23(15):3390-5.)
  • From SEER registry (1973-2001). 1343 cases. Histology according to WHO classification. Developed prognostic index based on histology and site.

Outcomes

• Yale (1990-2002)
  • Retrospective, 34 pts. Treated with RT as primary treatment; Median dose 40 Gy (range 20-48 Gy). No systemic disease.
  • Comparison of EORTC and WHO pathologic classification systems, which differ in characterizing these lesions, and therefore recommendations for treatment may differ (based on characterization as indolent or aggressive lymphomas)
  • 2004 PMID 14966086 -- "Primary cutaneous B-cell lymphoma treated with radiotherapy: a comparison of the European Organization for Research and Treatment of Cancer and the WHO classification systems." (Smith BD, J Clin Oncol. 2004 Feb 15;22(4):634-9.) -- Median f/u 3.4 yrs
    • 5-yr OS 96%, RFS 55%, LR-free survival 81%, extracutaneous relapse-free survival 79%. OS and RFS was 67% and 33% for leg-type DLBCL and 100% and 62-73% for other types
    • 62% (8/13) of initial relapses confined to skin (localregional or distant), 24% (8/34) of all pts. Distant relapse (+/- skin) in 38% (5/13) of all relapses or 15% (5/34) of all pts.
    • Pathologic: 68% of lesions classified as follicle center cell (i.e. indolent) by EORTC criteria are classified as DLBCL (i.e. aggressive) by WHO system, but the biologic behavior is indolent.
    • Increased risk of LR with dose < 36 Gy: 5-yr LR-free survival 50% (< 36 Gy) vs 90% (>= 36 Gy).
    • Conclusion: 40 Gy dose is recommended. Worse outcome for leg type; however, for the other lesions, DLBCL histology appears more indolent than in nodal lymphomas.

PCLBCL:

• European multicenter (1979-98) - PMID 11504742, 2001 — "Prognostic factors in primary cutaneous large B-cell lymphomas: a European multicenter study." Grange F et al. J Clin Oncol. 2001 Aug 15;19(16):3602-10.
  • Retrospective. 48 pts with PCLBCL of leg; 97 with PCFCCL.
  • On multivariate analysis, worse outcomes for location on leg, multiple lesions, and round cell morphology.

Treatment

Solitary lesion: Most often presents as a solitary lesion (~85%). Radiotherapy is preferred treatment for solitary lesions. Dose 40 Gy.

Multifocal disease:

• Netherlands (1985-97) - PMID 10561311, 1999 — "Treatment of multifocal primary cutaneous B-cell lymphoma: a clinical follow-up study of 29 patients." Bekkenk MW et al. J Clin Oncol. 1999 Aug;17(8):2471-8.
  • Retrospective. Included 29 pts who had involvement of >= 2 nonadjacent skin areas that did not fit into one radiation field without extracutaneous disease (14% of patients seen at this center). Pts treated with either chemotherapy (CHOP in most) or RT.
  • 16 pts had PCFCCL, 8 PCI, 5 PCLBCL of leg.
  • Excellent results in PCFCCL or PCI for either chemo or RT. All pts with PCLBCL relapsed with extracutaneous disease.