Dealing with diagnostic difficulties in CTCL

New Orleans - For a variety of reasons, cutaneous T-cell lymphoma (CTCL) - a low-grade lymphoma that typically presents in or on the skin - can be difficult to diagnose.

CTCL should not be confused with peripheral T-cell lymphomas (PTL) or adult T-cell lymphoma/leukemia (ATLL), which are more aggressive forms of lymphoma that may also present initially in or on the skin but require different types of treatment. Thus, accurate diagnosis is crucial.

According to Jacqueline M. Junkins-Hopkins, M.D., CTCL features overlap with more inflammatory dermatoses, making them difficult to differentiate from the pseudolymphoma and, as a result, often making accurate diagnosis problematic. In addition, she says, histopathology of the early disease is not always diagnosable, so that CTCL and its variants may escape diagnosis entirely.

Types and traits Dr. Junkins-Hopkins notes that CTCL presents itself as two main types: classic mycosis fungoides (MF) and non-mycosis fungoides or non-epidermotropic CTCL. She also says there are a multitude of MF variants, among which are:

Further, she identifies four variants of erythrodermic T-cell lymphoma - Sezary syndrome (an advanced form of MF), erythrodermic MF, ATLL, and HIV-related HTLV II - and notes what she refers to as "clonal disorders":

As to the clinical approach to CTCL infiltrates, Dr. Junkins-Hopkins says it should focus on history (duration, site, morphology and drugs, as well as course/treatment response); possible previous biopsies; and new biopsies.

"Often, more than one biopsy is necessary. They should be repeated if the histology is non-specific, and the deep-sampling variety is helpful," she says. "Adjunctive tests also are often needed."

Dr. Junkins-Hopkins adds that in the case of classic patch/plaque CTCL, or MF, if the clinical presentation points to MF, non-diagnostic histology is acceptable. In any case, she stresses, "Communication between clinician and pathologist is critical."

Typical histology of CTCL-MF, Dr. Junkins-Hopkins notes, includes the following features:

Patch/plaque MF histologic simulators include: