Mycosis fungoides and Sezary syndrome

Introduction to mycosis fungoides and Sezary syndrome Mycosisfungoides/Sezary's syndrome (MF/SS) is a subtype of erythroderma with cutaneous cutaneous lymphocyte tumor (PCTLC) SS as MF, accounting for 75% of primary cutaneous lymphoma. basic knowledge Sickness ratio: 0.0001% Susceptible people: no special people Mode of infection: non-infectious Complications: sepsis lymphoma erythroderma

Mycosis fungoides and the cause of Sezary syndrome

(1) Causes of the disease

The exact cause of MF/SS is currently unclear, and some retrospective studies suggest that environmental and occupational factors may be associated with onset, and have been reported in the cotton processing industry, tram and bus transportation, and MF or SS in the construction industry. The risk of morbidity has increased. Other studies have suggested that chronic exposure and stimulation of chemicals and pesticides are associated with morbidity, but recent large-scale case-control studies have failed to find correlations between these factors and MF or SS. Some scholars Adult T-cell leukemia/lymphoma virus (HTLV-1) was detected in peripheral blood or skin lesions of MF/SS patients, so HTIV-1 infection may be associated with MF/SS, and studies have shown that MF/SS The onset may be related to histocompatibility antigens, such as Aw31, Aw32, B8, Bw38 and DR5. MF/SS may have deletions and translocations of chromosomes 1 and 6, but it is unclear that these chromosome abnormalities are in MF. /SS occurs, the role of development.

(two) pathogenesis

The pathological feature is the epidermal infiltration of atypical mononuclear cells, which may involve the superficial dermis. These mononuclear cells can be clustered in the epidermis, called Pautrier microabscess, and the late vaginal reticular layer or even subcutaneous tissue. It can also invade the hair follicles and even the sebaceous gland epithelial cells. In the late plaques and tumors, except for MF, extracellular, eosinophils, tissue cells and plasma cells can be seen. In some cases, epithelioid cell granuloma is seen. It often indicates that the prognosis is better, the venules often proliferate, and the endothelial cells can also proliferate. The early dermal papilla layer often has mild edema, and there are different degrees of fibrosis in the late stage. The morphology of MF cells, Qiupengsen's observation shows that its morphology has pedigree changes. Can be expressed as small simple lymphocytes, transparent twisted nucleated cells (small, medium, large), transparent round nuclei (small, medium, large), T into immune cells to deformed multinucleated giant cells, MF cells under electron microscope Divided into two types, the small ones are similar in size to lymphocytes, and the larger ones are more than one-fold larger than lymphocytes. The transition between them is visible, and the nucleus accounts for most of the cells. The nucleus of the lower nucleus is highly distorted. Under the electron microscope, the nucleus is folded. The typical cerebral palpebral shape is heterogeneous. The heterochromatin is concentrated in the periphery of the nuclear membrane and its vicinity. There are few cytoplasm, few organelles, often located on one side of the nucleus, and a few mitochondria. Larger, emptyer, occasionally dense, MF/SS tumor cells are derived from mature helper T cells, CD4, most CD2, CD3, CD5, CD1- and CD8-, antigenic markers of frequently-immature T cells. In leu-8 and CD7, MF cells in individual cases express surface markers of inhibitory/cytotoxic T cells, CD8, and some patients may have abnormal expression of surface antigens, such as loss of whole T cell markers CD2, CD3 and CD5, CD4 and CD8 Sexual or double negative, most MF, tumor cells have a clonal rearrangement of the T cell receptor (TCR) gene.

The histological features of SS resemble MF, with or without epidermal infiltration. The diameter of Sezary cells is generally 10-40 m, and the nucleus is distorted, accounting for more than 80% of the whole cell. The typical one is brain-like, and the chromatin is deeply stained. Small cytoplasm, basophilic, sometimes small vacuoles visible in the nucleus, inclusions positive for PAS staining, S cells also a helper T cell phenotype, MF/SS involving lymph nodes, first invading the paracortex In the T cell-dependent region, other structures of the lymph nodes are destroyed, but the follicular center is not involved, and different degrees of tumor cell transformation can be seen in the lymph nodes.

Mycosis fungoides and prevention of Sezary syndrome

Mainly timely found timely treatment.

Mycosis fungoides and complications of Sezary syndrome Complications sepsis lymphoma erythroderma

1. Ulcerative lesions are easy to concurrent infection and secondary sepsis: it is the most common cause of acute death in MF.

2. About 8% of the MF course is converted to large cell lymphoma: from the diagnosis of MF to the median time of transformation 21.5 months, the disease is accelerated after transformation, the prognosis is poor, 15% to 20% of the MF course occurs outside the skin Invasion of organs, including lymph nodes and internal organs, invasion of skin and external organs rarely occurs in localized plaques and patches, while the incidence of extensive plaques is around 8%, but during tumor and systemic erythroderma The incidence rate is as high as 30% to 42%. The superficial lymph node enlargement in the early stage of skin lesions is often dermatologically responsive, and tumor invasion occurs. It usually involves the superficial lymph nodes within the lesion drainage area, such as the mediastinum and the abdomen. Perineal lymph nodes are generally invaded late, and internal organ invasion often occurs after lymph node invasion, most commonly involving the lungs, spleen, liver, central nervous system and gastrointestinal tract. In the early localized skin lesions, bone marrow invasion is rare, but When there are Sezary cells in the peripheral blood, the incidence of bone marrow invasion is significantly increased. Autopsy data indicate that advanced tumors can invade any organ.

Symptoms of mycosis fungoides and Sezary syndrome Common symptoms Folds when face is affected... Itchy itching, lymph nodes, scarring, generalized red plaque, malnutrition, hair loss

1. MF course can be very long, skin lesions are diverse, according to the disease development process and skin lesions, can be roughly divided into three phases, but different skin lesions in each phase can exist at the same time.

(1) Pre-stage: also known as patch stage or eczema sample period, this period can last for several months, several years, even 20 to 30 years, common skin lesions are non-specific, slight scale-like skin lesions, one after another It is easily misdiagnosed as eczema, neurodermatitis, psoriasis, pityriasis rosea and ichthyosis. In this period, the skin lesions of a few patients can spontaneously resolve and no longer progress to pathologically diagnosable MF, from the first occurrence of skin lesions to the diagnosis. The MF's elbows are up to 5 years or longer.

(2) Infiltration period: also known as plaque stage, developed from the lesions of the patch stage, can also be used as the first symptom of MF, manifested as irregular invasive plaque, dark red, smooth surface or uneven, infiltration The hair often falls off, and can also affect the oral mucosa. The skin lesions are often accompanied by obvious itching. The skin thickens during the infiltration period, and a typical "lion-like face" can appear. This period can be transferred to the tumor stage after several months.

(3) Tumor stage: plaque lesions can be further developed into tumors, which are ulcerated or exogenous paralyzed. Most patients with patch and plaque can not develop into tumor stage after treatment, and very few patients have onset. It can be expressed as a tumor lesion at the beginning.

(4) Others: Another type of skin lesion of MF is extensive erythroderma, with an incidence of about 10%, with or without plaque, tumor lesions, skin atrophy or mossy, often drama Itching, poor tolerance to cold stimulation, often accompanied by lymphadenopathy.

2.SS erythroderma with peripheral blood invasion (abnormal circulation of lymphocytes in the circulation>5%), known as Sezary syndrome, is generally considered to be a special type of MF, clinical manifestations of exfoliation, invasive red Skin disease and extensive lymphadenopathy, excessive keratinization and thickening of the skin of hands and soles, often cracking, finger and nail dystrophy and hair loss are common, and the skin is itchy, which is one of its characteristics, which often causes epidermal detachment due to scratching. Exudation and scarring.

Examination of mycosis fungoides and Sezary syndrome

1. Peripheral blood: Early hemoglobin is normal, mild anemia can be seen in the late stage, leukocytes increase in some cases, eosinophils and monocytes increase, lymphocytes decrease, which is especially common in patients with extensive plaques and tumors. The prognosis is poor. About 20% of patients can find abnormal lymphocytes in the peripheral blood, accounting for 6% to 35% of the number of nuclear cells, mostly below 20%.

2. Skin lesions: Lymph nodes find Sezary cells.

3. ESR: 80% of patients may have different degrees of ESR.

4. Immunological function test: The cellular immune response was negative or below normal. Fluorescence examination showed deposition of IgG, IgA, IgM and IgD in the vessel wall.

5. Bone marrow: The bone marrow of the localized lesions was rarely invaded, and occasionally the plasma cells increased, but the bone marrow involvement rate of SS patients increased significantly.

6. According to clinical manifestations, symptoms, signs, X-ray, CT, B-ultrasound, and biochemical examination.

Diagnosis and differentiation of mycosis fungoides and Sezary syndrome

diagnosis

The diagnosis of this disease mainly relies on pathological diagnosis, but the clinical and pathological specificity of MF patch and plaque early lesions are not obvious, which often causes difficulties in diagnosis. Patchy lesions are similar to various inflammatory skin diseases, some with MF relationship is close, even indistinguishable, but when clinical suspicious, biopsy pathological examination should be performed, and the clinical diagnosis should be closely combined. The diagnosis should be cautious.

Differential diagnosis

1. dermatitis and eczema skin diseases: edema between epidermal cells in the skin lesions, accompanied by scattered or aggregated lymphoid cells, sometimes similar to epidermal infiltrating cells and Pautrier microabscess in MF patches, but such skins Common degeneration in the lesion, disintegrated keratinocytes, the residual part of the keratinocytes are connected to each other in a star shape, while MF often has no obvious intercellular edema, and there is generally no effusion in the Pautrier microabscess. These two points are available for identification, but Need to combine clinical.

2. Mossy-like dermatitis-type skin diseases: common causes such as lichen planus, drug reaction and neurodermatitis, histologically, the dermal superficial lymphocytes are infiltrated and can be epidermal, and their morphology is similar to that of early MF cells. When seeing the above-mentioned mossy tissue reaction, attention should be paid to the identification of the MF patch stage.

3. Psoriasis-like dermatitis-type skin diseases: Commonly known as psoriasis, red pityriasis and pityriasis rosea, the histology of atypical cases, similar to the MF patch stage, combined with clinical follow-up differences.

4. Actinic reticulocyte disease: clinical and histological sometimes difficult to identify with MF, combined with medical history, light test or patch test.

5. Lymphoma-like papules: Histologically, type B lymphoma-like papules can also have deep nucleus staining, irregular polymorphic atypical cells, often combined with clinical history and MF distinction, and should pay attention to a small number of this disease can be transformed For MF.

6. Large cell lymphoma: MF tumor stage tumor cells are often similar to cutaneous large cell lymphoma, but the history of the two is often different, the latter tumor cells can be positive for CD30.

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