{"entity":{"id":"primary-cutaneous-marginal-zone-lymphoma","kind":"cancer","name":"Primary cutaneous marginal zone lymphoma","aka":["Primary cutaneous marginal zone B-cell lymphoma","Primary cutaneous marginal zone lymphoproliferative disorder","Primary cutaneous immunocytoma","Cutaneous immunocytoma","PCMZL"],"tldr":"Primary cutaneous marginal zone lymphoma is a very slow-growing lymphoma that appears as pink or purple lumps in the skin, usually on the arms or trunk, and almost never spreads inside the body. WHO-HAEM5 now calls it a lymphoproliferative disorder because it behaves so well; surgery or radiotherapy clears most lesions, and relapses in the skin are common but harmless.","summary":"WHO-HAEM5 renamed this entity primary cutaneous marginal zone lymphoproliferative disorder to reflect its indolent behaviour, keeping it beside the other marginal zone lymphomas; it was once called immunocytoma because of its plasmacytic differentiation (Alaggio 2022). In 137 patients, 51 percent had a solitary lesion, 29 percent regional and 20 percent generalised skin disease; surgical excision, local radiotherapy or both were the initial treatment in 86 percent, complete remission followed in 88 percent (93 percent of solitary or localised and 71 percent of multifocal cases), and cutaneous relapses occurred in 44 percent without loss of survival (J Am Acad Dermatol 2013). Unlike other marginal zone lymphomas, 39 percent of primary cutaneous cases with plasmacytic differentiation express IgG4, the highest rate in any B-cell lymphoma, against 1 of 120 non-cutaneous cases (Modern Pathology 2013).\n\nHow it differs from its parent: it is confined to the skin at diagnosis, is treated by dermatologists with excision or radiotherapy rather than systemic therapy, and its relapses are skin-only; extracutaneous spread is the exception. Borrelia infection has been implicated in some European cases.\n\nHow common: no registry share in the sources read.\n\nTreatment: excision or low-dose radiotherapy for solitary or localised lesions; observation, intralesional steroids or rituximab for multifocal disease; systemic therapy only for the rare extracutaneous spread, following the parent page (J Am Acad Dermatol 2013; Zucca 2020).","asOf":"2026-09-24","wikipedia":"https://en.wikipedia.org/wiki/Primary_cutaneous_marginal_zone_lymphoma","links":[{"label":"Alaggio 2022, Leukemia: the 5th edition WHO classification of haematolymphoid tumours, lymphoid neoplasms","url":"https://doi.org/10.1038/s41375-022-01620-2"},{"label":"J Am Acad Dermatol 2013: primary cutaneous marginal zone B-cell lymphoma, 137 patients","url":"https://doi.org/10.1016/j.jaad.2013.04.047"},{"label":"Modern Pathology 2013: IgG4 expression in primary cutaneous marginal zone lymphomas","url":"https://doi.org/10.1038/modpathol.2013.106"},{"label":"Zucca 2020, Annals of Oncology: marginal zone lymphomas, ESMO clinical practice guidelines","url":"https://doi.org/10.1016/j.annonc.2019.10.010"}],"tags":["subtype-page","wave4","haematologic","rare"],"related":["marginal-zone-lymphoma","malt-lymphoma","primary-cutaneous-follicle-centre-lymphoma","cutaneous-t-cell-lymphoma"],"cancers":[],"sections":[],"technologies":[],"targets":[],"drugs":["rituximab"],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"group":"haematologic","burden":"Rare and indolent; the largest clinical series holds 137 patients, 51 percent presenting with a solitary lesion (J Am Acad Dermatol 2013). No registry share is in the sources read.","subtypes":["Primary cutaneous marginal zone lymphoproliferative disorder, solitary lesion (half of cases)","Multifocal or generalised cutaneous disease","Class-switched (IgG4-expressing) cutaneous marginal zone lymphoma","Borrelia-associated cutaneous marginal zone lymphoma (Europe)"],"biomarkers":["Plasmacytic differentiation with light chain restriction","IgG4 expression (39 percent)","Staging to exclude extracutaneous disease","Borrelia serology in endemic areas"],"standardOfCare":[{"setting":"Solitary or localised","approach":"Excision or low-dose radiotherapy.","refs":["marginal-zone-lymphoma"]},{"setting":"Multifocal","approach":"Observation, intralesional steroids or rituximab; systemic therapy only for extracutaneous spread.","refs":["rituximab","marginal-zone-lymphoma"]}],"stateOfArt":[],"history":[],"pipeline":[],"openProblems":[],"parent":"marginal-zone-lymphoma"},"route":"/cancers/primary-cutaneous-marginal-zone-lymphoma/","neighbours":{"cancer":[{"id":"cutaneous-t-cell-lymphoma","kind":"cancer","name":"Cutaneous T-cell lymphoma (mycosis fungoides and Sezary syndrome)","route":"/cancers/cutaneous-t-cell-lymphoma/"},{"id":"malt-lymphoma","kind":"cancer","name":"Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma)","route":"/cancers/malt-lymphoma/"},{"id":"marginal-zone-lymphoma","kind":"cancer","name":"Marginal zone lymphoma","route":"/cancers/marginal-zone-lymphoma/"},{"id":"primary-cutaneous-follicle-centre-lymphoma","kind":"cancer","name":"Primary cutaneous follicle centre lymphoma","route":"/cancers/primary-cutaneous-follicle-centre-lymphoma/"},{"id":"sezary-syndrome","kind":"cancer","name":"Sezary syndrome","route":"/cancers/sezary-syndrome/"}],"drug":[{"id":"rituximab","kind":"drug","name":"Rituximab","route":"/drugs/rituximab/"}]}}