Biopsy Requisition Builder
Tell dermatopathology to rule out mycosis fungoides and request the right workup.
Why this matters
Nonspecific "spongiotic dermatitis" reads are a leading cause of delayed CTCL diagnosis. Telling pathology to rule out MF and ordering the right stains and clonality studies changes what gets reported.
Specimen details
Biopsy pearls
- Hold topical/intralesional corticosteroids for 2–4 weeks before biopsy — treatment can suppress the diagnostic infiltrate.
- Sample the thickest / most indurated lesion; avoid recently treated or excoriated sites.
- Take multiple biopsies (2–4) from different representative lesions to improve yield.
- Use a 4–6 mm punch (or a broad shave/incisional biopsy of a plaque) reaching reticular dermis.
- Send fresh/appropriately fixed tissue if flow cytometry or molecular clonality is requested.
Requisition text
Paste into the pathology order's clinical history field.
CLINICAL HISTORY / REQUEST TO PATHOLOGY Clinical question: Rule out mycosis fungoides / cutaneous T-cell lymphoma (CTCL). Specimen: lesion. Requested immunohistochemistry: CD3, CD4, CD8, CD7, CD30, CD20 Requested molecular studies: TCR gene rearrangement (PCR or NGS) Please correlate with clinical presentation and comment on features of MF/CTCL (epidermotropism, Pautrier microabscesses, atypical lymphocytes, CD7 loss).
Immunohistochemistry panel
CD3Pan–T-cell marker; establishes T-cell lineage of the infiltrate.
CD4Helper T-cell marker; MF is typically CD4-predominant.
CD8Cytotoxic T-cell marker; assesses the CD4:CD8 ratio and CD8+ variants.
CD7Frequently reduced or lost in MF; a supporting feature but not specific (CD7 loss also occurs in benign dermatoses).
CD30Marks large-cell transformation and lymphomatoid papulosis / pcALCL.
CD20B-cell marker; helps exclude a B-cell lymphoid process.
Molecular studies
TCR gene rearrangement (PCR or NGS)
Detects a clonal T-cell population supporting CTCL; NGS clonality is more sensitive than PCR.