Cutaneous Gamma-Delta T-Cell Lymphoma

 Malignant T cells rim around adipocytes


image Prominent karyorrhexis/apoptosis and angioinvasion





Ancillary Tests




• Immunohistochemistry: TCRδ1(+), βF1(-), CD56(+), CD4(-), CD8(-)

• EBER(-), cytotoxic markers (+)

• T-cell receptor gene rearrangement


Top Differential Diagnoses




• Subcutaneous panniculitis-like T-cell lymphoma
image Panniculitis but not in dermis or epidermis; lacks ulceration; TCRδ1(-), βF1(+)

image Much better prognosis than CGDTCL

• Peripheral T-cell lymphoma, not otherwise specified

• Lupus profundus panniculitis
image Similar inflammation in the subcutis in panniculitic pattern

image Lobular panniculitis, but contains plasma cells and germinal centers, unlike CGDTCL

• Mycosis fungoides/pagetoid reticulosis

image
CGDTCL Presenting As an Ulcerated Mass
Cutaneous γδ T-cell lymphoma (CGDTCL) shows a large raised lesion with ulcer and satellite lesions. (Courtesy C. Sander, MD.)


image
Primary CGDTCL Diffusely Involving Skin
The atypical lymphoid infiltrate diffusely involves the epidermis image, dermis image, and also extended into the subcutaneous adipose tissue (not shown), typical of this neoplasm.

image
Panniculitis With Karyorrhexis
In the same case, there is a deep infiltrate showing lobular panniculitis composed of atypical T cells rimming fat lobules with prominent apoptosis/karyorrhexis image.

image
CD3 Immunohistochemical Stain in CGDTCL
At high power, this CD3 stain highlights the atypical T cells that are lining fat cells. This feature is common to CGDTCL and to subcutaneous panniculitis-like T-cell lymphoma. (Courtesy L. J. Medeiros, MD.)


TERMINOLOGY


Abbreviations




• Cutaneous γδ T-cell lymphoma (CGDTCL)


Synonyms




• Subcutaneous panniculitis-like T-cell lymphoma with γδ cells


Definitions




• T-cell lymphoma arising in skin, which is composed of cytotoxic γδ T cells
image Does not include subcutaneous panniculitis-like T-cell lymphoma composed of αβ cells


ETIOLOGY/PATHOGENESIS


Immunosuppression or Dysregulation of T Cells




• Found in many patients


Chronic Antigenic Stimulation




• Speculative but possibly involved in pathogenesis


Cell of Origin




• γδ T cells
image Involved with mucosal and epithelial immune system function


CLINICAL ISSUES


Epidemiology




• Incidence
image Rare tumor

– < 1% of all cutaneous T-cell lymphomas

• Age
image Commonly adults

• Sex
image No gender preponderance


Site




• Mostly extremities
image Sometimes mucosal sites, where normal γδ T cells are found

image Metastasis common

– Spread to lungs, liver, kidneys, oral mucosa, and brain

– Usually not in bone marrow, lymph nodes, or spleen


Presentation




• 1 or multiple skin lesions, sometimes with ulceration
• Patches due to epidermal infiltrates

image Plaques or nodules due to dermal infiltrates

– ± ulcerated epidermis

• Hemophagocytic syndrome (HPS) may be present in 45% of cases
image More often in subcutaneous lesions
– Related to release of cytotoxic molecules

• B symptoms are frequent


Laboratory Tests




• Cytopenias and ↑ liver function tests

• HHV8, HTLV-1, and EBV serologies (-)


Treatment




• Multiagent chemotherapy ± radiotherapy
image Aggressive therapy followed by allogeneic allogenic stem cell transplant may be promising treatment modality

image Brentuximab vedotin can be treatment option for patients with CD30(+) CGDTCL


Prognosis




• Poor prognosis
image 5-yr survival: ~ 11%; median survival: ~ 15 months

image Subcutaneous disease is poor prognostic indicator

– Better prognosis if only disease in dermis or epidermis

image HPS is poor prognostic indicator

image May have indolent course in children


MICROSCOPIC


Histologic Features




• May involve epidermis, dermis, &/or subcutis
image Epidermal

– Epidermotropism ranges from mild to marked

– Can mimic mycosis fungoides or pagetoid reticulosis

image Dermal

– More dermal involvement typically present than in subcutaneous panniculitis-like T-cell lymphoma

Only gold members can continue reading. Log In or Register to continue

Apr 24, 2017 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Cutaneous Gamma-Delta T-Cell Lymphoma
Premium Wordpress Themes by UFO Themes
%d bloggers like this: