Ch. 24 - Cutaneous T/NK-cell lymphomas and myeloid leukemia Flashcards
Mycosis fungoides, patch stage
Junctional (vacuolar interface) large dark lymphocytes with irregular nuclear contours and perinuclear halos. Pautrier’s microabscesses.
Mycosis fungoides, plaque stage
Like patch stage, but with a denser, band-like infiltrate in the upper dermis (including atypical lymphocytes)
Mycosis fungoides, tumor stage
Dense, nodular lymphocyte infiltrate in dermis. May acquire CD30 and lose epidermotropism.
What is the typical immunophenotype of MF?
CD3+, CD4+
CD7-, CD8-
CD30- (can be positive in advanced disease)
MF, pagetoid reticulosis variant
Entirely epidermotropic patches/plaques on distal extremities. Can be CD4-/CD8+. Great prognosis.
MF, folliculotropic variant
Follicular papules and boggy plaques. Atypical lymphocytes infiltrate follicular epithelium. Eosinophils and follicular mucinosis.
Granulomatous slack skin
Pendulus intertriginous skin with massive dermal/subQ infiltrate with huge multinucleate giant cells. Slowly progressive.
Sezary syndrome
Histopathologic findings similar to MF (eg Pautrier’s microabscesses) but with peripheral blood sezary (cerebriform) nuclei.
Adult T-cell leukemia/lymphoma
Dense dermal infiltrate with CD3/4+, CD25+ lymphocytes with peripheral blood flower cells with multilobed nuclei.
What is the difference between MF and Sezary syndrome?
MF arises from skin-resident memory T-cells. Sezary arises from central memory T-cells.
Describe the organism that causes ATLL
HTLV-1, a virus transmitted by sexual contact and blood transfusion. Found in southwestern japan and the west caribbeans.
Lymphomatous papulosis, type A
CD30+ Reed-sternberg-like cells with mixed background infiltrate. Most common type.
Lymphomatous papulosis, type B
Epidermotropic infiltrate of CD3+, CD30- small lymphocytes. Resembles MF.
Lymphomatous papulosis, type C
Diffuse sheets of CD30+ Reed-sternberg-like cells in dermis. May be indistinguishable from anaplastic large cell lymphoma.
Lymphomatoid papulosis, type D
Markedly epidermotropic CD8+, CD30+ lymphocytes. Mimics primary cutaneous aggressive epidermotropic CD8+ cytotoxic T-ell lymphoma.
Lymphomatoid papulosis, type E
Angioinvasive CD30+ Beta F1+ lymphocytes. Mimics extranodal NK-T-cell lyphoma, nasal type.
Recall the lesions which lymphomatoid papulosis types B-E can mimic.
B: MF
C: ALCL
D: Primary cutaneous aggressive epidermotropic CD8+ T-cell lymphoma
E: Extranodal NK/T-cell lymphoma, nasal type
Primary cutaneous anaplastic large cell lymphoma
(genetics?)
Sheets of Reed-Sternberg-like cells in dermis, largely CD30+.
t(2;5) EML-ALK translocation
Subcutaneous panniculitis-like T-cell lymphoma
(key features?)
Lace-like fat infiltration with CD8+ TCR- lymphocytes. Beanbag cells (macrophages filled with karyorrhectic debris)
Associated with hemophagocytic syndrome.
Extranodal NK/T-cell lymphoma, nasal type
(immunophenotype? cause?)
Dense dermal/SubQ lymphoid infiltrate with angiocentricity and necrosis.
CD2+, CD3e+, CD56+ (NK-cell markers)
EBV
Primary cutaneous aggressive epidermotropic CD8+ cytotoxic T-cell lymphoma
(immunophenotype?)
Band-like, lichenoid lymphoid infiltrate with epidermotropism.
CD3+, CD8+, perforin/granzyme & TIA-1+.
Cutaneous gamma-delta T-cell lymphoma
Broad lyphoid infiltrate with TCR gamma-delta+ CD3+ CD56+ phenotype. Worse prognosis than subcutaneous panniculitis-like T-cell lymphoma.
Primary cutaneous CD4+ small/medium T-cell lymphoma.
Dermal/SubQ infiltrate with CD3+, CD4+, CD8/30- phenotype. Hard to distinguish from MF.
Hydroa vacciniforme-like lymphoma
(associations?)
Epidermal ulceration with angiocentric lymphocytes.
Associated with EBV, hypersensitivity to mosquito bites.
