T-cell prolymphocytic leukemia overview
Synonyms and keywords: T-cell chronic lymphocytic leukemia; "Knobby" type of T-cell leukemia; T-prolymphocytic leukemia/T-cell lymphocytic leukemia- Kiel;  T-PLL

# Overview
T-cell-prolymphocytic leukemia (also known as T-PLL) is a rare, mature T-cell leukemia with aggressive behavior and predilection for blood, bone marrow, lymph nodes, liver, spleen, and skin. T-cell prolymphocytic leukemia was first described by Catovsky in 1973. There is no classification system for T-cell prolymphocytic leukemia. The inversion of chromosome 14 (14q11) has been associated with the development of T-cell prolymphocytic leukemia. T-cell prolymphocytic leukemia is very rare, and it represents 2% of all small lymphocytic leukemias in adults. T-cell prolymphocytic leukemia is more commonly observed among young adult patients aged between 30 to 40 years old. Males are slightly more affected with are more commonly affected with T-cell prolymphocytic leukemia than females. Laboratory findings consistent with the diagnosis of T-cell prolymphocytic leukemia, include high lymphocyte count (> 100 x 109/L), anemia, thrombocytopenia, and negative HTLV-1 serology. There are no specific imaging findings associated with T-cell prolymphocytic leukemia. Prognosis is generally poor, and the median survival time of patients with T-cell prolymphocytic leukemia is approximately 7 months. The mainstay of therapy for T-cell prolymphocytic leukemia is alemtuzumab (anti-CD52). However, T-cell prolymphocytic leukemia is often resistant to therapy. Autologous and allogeneic stem cell transplants is the mainstay of therapy for patients who achieve remission.

# Historical Perspective
T-cell prolymphocytic leukemia was first described 40 years ago and was classified in 1994.

# Classification
T-cell prolymphocytic leukemia is classified into three variants based on its morphology.

# Pathophysiology
T-PLL has the immunophenotype of a mature (post-thymic) T-lymphocyte, and the neoplastic cells are typically positive for pan-T antigens. Clonal TCR gene rearrangements for the  and  chains are typically found. It arises from mature (post-thymic) T-cell, which are normally involved in in cell-mediated immunity. On microscopic histopathological analysis, T-cell prolymphocytic leukemia has characteristic findings. In the peripheral blood, T-PLL consists of medium-sized lymphocytes with single nucleoli and basophilic cytoplasm with occasional blebs or projections. Different variants of T-cell lymphocytic leukemias can be differentiated based on the microscopic and gross finding.

# Causes
T-cell prolymphocytic leukemia is caused by gene mutations and chromosomal abnormalities. Details of which are described below.

# Differentiating Xyz from Other Diseases
T-cell prolymphocytic leukemia presents with Lymphadenopathy, hepatomegaly, and fever which are also presenting symptoms of a number of other conditions.

# Epidemiology and Demographics
T-cell prolymphocytic leukemia is a rare condition. Its incidence increases with age, with ataxia telangiectasia, the median age at diagnosis is 30 years.

# Risk Factors
There are no identified risk factors of T-cell prolymphocytic leukemia.

# Screening
Screening for T-cell prolymphocytic leukemia is not done.

# Natural History, Complications, and Prognosis
T-cell prolymphocytic leukemia is diagnosed after its symptoms appear. Failure to treat can result in multiple organ failure.

# Diagnosis
There is no established diagnostic criteria.

# History and Symptoms
T-cell prolymphocytic leukemia presents with fever, weight loss and night sweats.

# Treatment
T-cell prolymphocytic leukemia responds better when combinations of chemotherapy drugs are used. Monoclonal antibodies are a type of biological therapy that has been effective in treating certain types of leukemias. Splenectomy and external beam radiation therapy to the spleen may be used in some people with prolymphocytic leukemia.

# Primary Prevention
There are no established measures for the primary prevention of T-cell prolymphocytic leukemia.

# Secondary Prevention
There are no established measures for the secondary prevention of T-cell prolymphocytic leukemia.