T-cell prolymphocytic leukemia
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Maria Fernanda Villarreal, M.D. [2]
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
- In 1973, T-cell prolymphocytic leukemia was first described by Catovsky.[1]
- In 1994, T-cell prolymphocytic leukemia was described as a separate entity from other large grandular lymphocytic disorders.[2]
Classification
- Morphologically T-cell prolymphocytic leukemia has three variants:[3]
- Typical (75 percent)
- Small cell variant (20 percent)
- Cerebriform (Sézary cell-like) variant (5 percent)
Pathophysiology
- T-cell prolymphocytic leukemia arises from mature (post-thymic) T-cell, which is normally involved in in cell-mediated immunity.
- The inversion of chromosome 14 (14q11) has been associated with the development of T-cell prolymphocytic leukemia.
- Patients with T-cell prolymphocytic leukemia have TCR gene rearrangements for the γ and δ chains.
- Mutations of chromosome 8 are seen in approximately 75% of patients.
- On gross pathology, characteristic findings of T-cell prolymphocytic leukemia, include:[3]
- No remarkable findings
- On microscopic histopathological analysis, characteristic findings of T-cell prolymphocytic leukemia, include:[3]
- The immunophenotype CD4+/CD8- (present in 60% of cases)
- The immunophenotype CD4+/CD8+ (present in 25%)
- The immunophenotype CD4-/CD8+ (15% of cases)
Immunophenotype
- T-cell prolymphocytic leukemia cells express different markers including:
- CD52 (strongly)
- Pan-T cell markers such as:
- CD2
- CD3 (might be low or high level)
- CD7
- Oncogene TCL1
- CD4+/CD8- (present in 60% of cases)
- CD4+/CD8+ (present in 25%, unique for T-cell prolymphocytic leukemia)
- CD4-/CD8+ (15% of cases)
- Negative terminal deoxynucleotidyl transferase (TdT)
Genetic
- There are many chromosomal abnormalities in T-cell prolymphocytic leukemia, which mostly involve chromosome 14. Different types of genetic abnormalities are as follows:
- Inv(14)
- t(14;14)(q11;q32)
- t(X;14)(q28;q11) which involves a homolog of TCL1, MTCP1 (mature T cell proliferation 1 gene)
- idic(8p11)
- t(8;8)
- Trisomy 8q
- Del(12p13)
- Abnormalities in chromosome 6
- Abnormalities in chromosome 17
- Deletion of TP53 gene
- Deletions of or missense mutations at the ataxia telangiectasia mutated (ATM) locus 11q23
Causes
- Common causes of T-cell prolymphocytic leukemia, include:[3]
- Genetic mutations (e.g. Trisomy 8, chromosomal abnormalities)
Differentiating T-cell Prolymphocytic Leukemia from Other Diseases
- T-cell prolymphocytic leukemia must be differentiated from other diseases that cause lymphadenopathy, hepatomegaly, and fever, such as:[3]
- Sézary syndrome
- Cutaneous T cell lymphoma
- Angioimmunoblastic T cell lymphoma
- B-cell prolymphocytic leukemia
Epidemiology and Demographics
- T-cell prolymphocytic leukemia is very rare, and it represents 2% of all small lymphocytic leukemias in adults.
- The incidence of T-cell prolymphocytic leukemia increases with age; the median age at diagnosis is 65 years.[3]
- Patients with ataxia telangiectasia and T-cell prolymphocytic leukemia are young adults; the median age at diagnosis is 30 years.
- Males are slightly more affected with T-cell prolymphocytic leukemia than females.
- There is no racial predilection for T-cell prolymphocytic leukemia.
Risk Factors
- There are no risk factors associated with the development of T-cell prolymphocytic leukemia.[3]
Screening
There is insufficient evidence to recommend routine screening for T-cell prolymphocytic leukemia.
Natural History, Complications and Prognosis
- The majority of patients with T-cell prolymphocytic leukemia are symptomatic at the time of diagnosis.
- Early clinical features, include fever, fatigue, and lymphadenopathy.
- If left untreated, patients with T-cell prolymphocytic leukemia may progress to develop multiple organ failure.
- Common complications of T-cell prolymphocytic leukemia, include:[3]
- Graft-versus-host disease (allogeneic transplant)
- Infections
- Bleeding
- Prognosis is generally poor, and the median survival time of patients with T-cell prolymphocytic leukemia is approximately 7 months.[3]
Diagnosis
Diagnostic Study of Choice
History and Symptoms
- Symptoms of T-cell prolymphocytic leukemia may include the following:[3]
Physical Examination
- Patients with T-cell prolymphocytic leukemia usually appear pale and malnourished.
- Physical examination may be remarkable for:[3]
- Hepatomegaly
- Splenomegaly
- Generalized lymphadenopathy
- Skin infiltration
- Serous effusions:
- Pleural effusion
- Peritoneal effusion
- Central nervous system involvement (very rare)
Laboratory Findings
- Laboratory findings consistent with the diagnosis of T-cell prolymphocytic leukemia, include:[3]
- High lymphocyte count (> 100 x 109/L)
- Anemia
- Thrombocytopenia
- Negative human T lymphotropic virus (HTLV) serology
- Peripheral Blood Smear demonstrated predominance of lymphocytes:
- Typical variant:
- Medium-sized lymphocytes
- Condensed chromatin and a visible nucleolus
- Round nucleus
- Slightly basophilic cytoplasm
- Cytoplasmic protrusionn
- Small cell variant
- Small tumor cells with condensed chromatin
- Small nucleolus visible by electron microscopy
- Cerebriform (Sézary cell-like) variant
- Irregular nuclear outline
- Similar to cerebriform nucleus of Sézary cells seen in mycosis fungoides
- Typical variant:
Electrocardiogram
X-ray
Echocardiography or Ultrasound
CT scan
MRI
Other Imaging Findings
Other Diagnostic Studies
- There are no specific imaging findings associated with T-cell prolymphocytic leukemia.[3]
Treatment
Medical Therapy
- The mainstay of therapy for T-cell prolymphocytic leukemia, include:[3]
- Alemtuzumab (anti-CD52)
- T-cell prolymphocytic leukemia is often resistant to therapy.
Surgery
- Autologous and allogeneic stem cell transplants is the mainstay of therapy for patients who achieve remission.
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.
References
- ↑ Catovsky D, Galetto J, Okos A, Galton DA, Wiltshaw E, Stathopoulos G (August 1973). "Prolymphocytic leukaemia of B and T cell type". Lancet. 2 (7823): 232–4. PMID 4124423.
- ↑ Harris NL, Jaffe ES, Stein H, Banks PM, Chan JK, Cleary ML, Delsol G, De Wolf-Peeters C, Falini B, Gatter KC (September 1994). "A revised European-American classification of lymphoid neoplasms: a proposal from the International Lymphoma Study Group". Blood. 84 (5): 1361–92. PMID 8068936.
- ↑ 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 3.11 3.12 3.13 Graham RL, Cooper B, Krause JR (2013). "T-cell prolymphocytic leukemia". Proc (Bayl Univ Med Cent). 26 (1): 19–21. PMC 3523759. PMID 23382603.