What are Pautrier microabscesses, and in which skin layer are they located?

Pautrier microabscesses are intraepidermal accumulations of atypical lymphocytes. They are located within the epidermis. This feature is characteristic of the plaque stage of mycosis fungoides and is one of the primary histopathological diagnostic criteria for the disease.

What is the precise immunophenotype (CD markers) of malignant cells in mycosis fungoides?

In the most common classic variant of mycosis fungoides, the malignant cells have the immunophenotype of mature memory cells (α/β T-helper cells). The main immunophenotype of the infiltrating cells includes the following markers: βF1+, CD2+, CD3+, CD4+, CD5+, CD7+, CD8-, CD45RO+. A characteristic feature is the loss of expression of the pan-T-cell marker CD7 in more than 10% of lymphocytes. In advanced stages of the disease, complete or partial loss of expression of pan-T-cell antigens CD2, CD3, CD5, and CD7 may be observed, along with an increased CD4/CD8 ratio greater than 8:1.

What are cerebriform lymphocytes?

They are pathological lymphocytes with convoluted nuclei, which serve as a key cellular component of the infiltrate in mycosis fungoides.

How does Sézary syndrome differ from classic mycosis fungoides?

Sézary syndrome is a leukemic variant in which malignant cells enter the peripheral blood, accompanied by erythroderma and generalized lymphadenopathy.

Which transformation is most dangerous in mycosis fungoides?

Transformation into a large-cell lymphoma, which significantly worsens the prognosis of the disease.

Home › Pathology › Cutaneous Lymphomas

Cutaneous Lymphomas

Lymphomata cutis

For medical students2 min readUpdated 2026-10-10

Primary cutaneous lymphomas are a group of malignant lymphoid neoplasms that develop primarily in the skin without evidence of extracutaneous involvement at the time of diagnosis. In the majority of cases (approximately 60–65%), they are of T-cell origin.

T-cell frequency60–65% of all primary cutaneous lymphomas are of T-cell origin.

Mycosis fungoidesThe most common form, accounting for 50% of all primary cutaneous lymphomas.

B-cell lymphomasAccount for 20–25% of all cutaneous lymphoproliferative disorders.

Sézary syndromeA leukemic variant of cutaneous T-cell lymphoma characterized by a classic triad of signs.

T-Cell Lymphomas

This is the most clinically significant group of cutaneous neoplasms. The most frequent variant is Mycosis fungoides. As the disease progresses, the cellular infiltrate becomes diffuse and can extend into the subcutaneous adipose tissue. A characteristic morphological feature is the presence of cerebriform lymphocytes—cells with convoluted nuclei resembling the surface of the brain.

Transformation and Prognosis

In advanced stages, mycosis fungoides may undergo large-cell transformation. This is a critical milestone in pathogenesis, as progression to a large-cell lymphoma significantly worsens the patient's prognosis.

Sézary Syndrome

This is a distinct leukemic form of cutaneous T-cell lymphoma. Diagnosis requires the classic triad:

Erythroderma (generalized skin redness).
Lymphadenopathy (enlarged lymph nodes).
Presence of malignant T-lymphocytes, known as Sézary cells, in the skin and peripheral blood.

B-Cell Lymphomas

B-cell variants represent distinct clinicopathological subtypes of extranodal lymphomas. They are less common than T-cell lymphomas, accounting for approximately a quarter of all cutaneous lymphoproliferative processes.

Mnemonic

Sézary Triad: E-L-S (Erythroderma, Lymphadenopathy, Sézary cells in blood).

Frequently asked questions

What are Pautrier microabscesses, and in which skin layer are they located?: Pautrier microabscesses are intraepidermal accumulations of atypical lymphocytes. They are located within the epidermis. This feature is characteristic of the plaque stage of mycosis fungoides and is one of the primary histopathological diagnostic criteria for the disease.
What is the precise immunophenotype (CD markers) of malignant cells in mycosis fungoides?: In the most common classic variant of mycosis fungoides, the malignant cells have the immunophenotype of mature memory cells (α/β T-helper cells). The main immunophenotype of the infiltrating cells includes the following markers: βF1+, CD2+, CD3+, CD4+, CD5+, CD7+, CD8-, CD45RO+. A characteristic feature is the loss of expression of the pan-T-cell marker CD7 in more than 10% of lymphocytes. In advanced stages of the disease, complete or partial loss of expression of pan-T-cell antigens CD2, CD3, CD5, and CD7 may be observed, along with an increased CD4/CD8 ratio greater than 8:1.
What are cerebriform lymphocytes?: They are pathological lymphocytes with convoluted nuclei, which serve as a key cellular component of the infiltrate in mycosis fungoides.
How does Sézary syndrome differ from classic mycosis fungoides?: Sézary syndrome is a leukemic variant in which malignant cells enter the peripheral blood, accompanied by erythroderma and generalized lymphadenopathy.
Which transformation is most dangerous in mycosis fungoides?: Transformation into a large-cell lymphoma, which significantly worsens the prognosis of the disease.

Go deeper

Differential diagnosis between cutaneous T- and B-cell lymphomas.
TNM staging system for mycosis fungoides.
Morphological features of Sézary cells on electron microscopy.
The role of immunohistochemistry in phenotyping cutaneous lymphomas.
Histiocytic and dendritic cell neoplasms as rare forms of lymphoproliferative disorders.