Revised clinicopathologic proposal on “in situ” B-cell lymphomas, as acknowledged by the WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues (2008)2-4
| . | Clinical meanings . | Treatment option . |
|---|---|---|
| “In situ” FL | ||
| Without overt lymphoma | Indolent | Follow-up |
| With overt lymphoma | Synchronous (early infiltration by synchronous FL) | Therapy as for overt lymphoma “in situ” site should be considered as involved |
| Metachronous (preceding FL by years or associated with other lymphomas: DLBCL, SMZL, MCL, and cHL) | Biopsy is mandatory Therapy as for overt lymphoma Consider site of initial “in situ” lymphoma | |
| “In situ” MCL | ||
| Without overt lymphoma | Not always indolent | Follow-up (closer than in FL) |
| With overt lymphoma | Synchronous (with synchronous MCL or FL) | Therapy as for overt lymphoma “in situ” site should be considered as involved |
| Metachronous (widespread disease; aggressive behavior) | Biopsy is mandatory Therapy as for overt lymphoma Consider site of initial “in situ” lymphoma |
| . | Clinical meanings . | Treatment option . |
|---|---|---|
| “In situ” FL | ||
| Without overt lymphoma | Indolent | Follow-up |
| With overt lymphoma | Synchronous (early infiltration by synchronous FL) | Therapy as for overt lymphoma “in situ” site should be considered as involved |
| Metachronous (preceding FL by years or associated with other lymphomas: DLBCL, SMZL, MCL, and cHL) | Biopsy is mandatory Therapy as for overt lymphoma Consider site of initial “in situ” lymphoma | |
| “In situ” MCL | ||
| Without overt lymphoma | Not always indolent | Follow-up (closer than in FL) |
| With overt lymphoma | Synchronous (with synchronous MCL or FL) | Therapy as for overt lymphoma “in situ” site should be considered as involved |
| Metachronous (widespread disease; aggressive behavior) | Biopsy is mandatory Therapy as for overt lymphoma Consider site of initial “in situ” lymphoma |
DLBCL indicates diffuse large B-cell lymphoma; SMZL, splenic marginal zone lymphoma; and cHL, classic Hodgkin lymphoma.