Peripheral T-Cell and Natural Killer Cell Neoplasms

 PERIPHERAL T-CELL AND NATURAL KILLER CELL NEOPLASMS

Peripheral T-cell lymphoma, unspecified is a “wastebasket” diagnostic category.

Adult T-cell leukemia/lymphoma (ATLL) is a malignant T-cell disorder (CD4-T cells) due to HTLV-1 infection. It is often seen in Japan and the Caribbean. Clinical symp-toms include skin lesions, hypercalcemia, enlarged lymph nodes, heptomegaly, and splenomegaly. Microscopically, characteristic hyperlobated “4-leaf clover” lympho-cytes can be found in the peripheral blood.

Mycosis fungoides is a malignant T-cell disorder (CD4+ cells) that has a better prognosis than ATLL. It can present with a generalized pruritic erythematous rash (no hypercalcemia), which develops as a sequence of skin changes:

inflammatory eczematous stage → plaque stage → tumor nodule stage

Microscopically, atypical PAS-positive lymphocytes are present in the epidermis (epidermotropism); aggregates of these cells are called Pautrier microabscesses. If there is erythroderma and cerebriform Sézary cells are present in peripheral blood, the condition is called Sézary syndrome.

Comments

Post a Comment

Popular posts from this blog

Lymphoid Neoplasms

  LYMPHOID NEOPLASMS Lymphoid neoplasia  is grouped according to the 2008 WHO classification as follows   (note that B and T lymphoblastic lymphoma/leukemia is grouped by the WHO with myeloid neoplasia):   •           Mature B-cell neoplasms   •           Mature T-cell and NK-cell neoplasms   •           Hodgkin lymphoma   •           Histiocytic and dendritic cell neoplasms   •           Posttransplantation lymphoproliferative disorders
Read more

Infectious Arthritis

Image
  INFECTIOUS ARTHRITIS   Suppurative arthritis  may result from seeding of the joint during bacteremia. Other   routes include spread from an adjacent site of infection and direct inoculation. Infecting organisms include gonococci,  Staphylococcus, Streptococcus ,  H. influen-zae , and gram-negative bacilli.   Suppurative arthritis causes a tender, painful, swollen, and erythematous joint. Large joints (knee, hip, shoulder) are most often infected, and the arthritis is usually monoarticular. Joint aspiration shows cloudy synovial fluid that clots readily and has a high neutrophil count. Gram stain and culture are positive in 50–70% of cases. Treatment is rapid intervention with antibiotics to prevent permanent joint damage.     Lyme disease  is caused by the spirochete   Borrelia burgdorferi . The disease is arthro-pod-borne, spread by deer ticks ( Ixodes dammini ). Symptoms are skin rash (ery-thema chronicum migrans), and migratory...
Read more

Normocytic Anemias

Image
  NORMOCYTIC ANEMIAS Anemias of blood loss. Acute blood loss may cause shock or death. If the patient sur-vives, the resulting hemodilution caused by shift of water from the interstitium will lower the hematocrit. There will be a marked reticulocytosis in 5–7 days. Chronic blood loss, such as from the gastrointestinal tract or from the gynecologic system, may result in iron deficiency anemia. Hemolytic anemias. ·              In  intravascular (IV) hemolysis , release of hemoglobin into the blood causes hemoglobinemia and hemoglobinuria; increased bilirubin from erythrocytes causes jaundice and an increased risk of pigment (bilirubin) gallstones. The hemoglobin may be oxidized to methemoglobin, which causes methemoglo-binemia and methemoglobinuria. Markedly decreased (because they have been used up) hemoglobin-binding proteins in the blood, such as haptoglobin and hemopexin, are characteristic. No splenomegaly is seen...
Read more