T‐cell prolymphocytic leukemia: Review of an entity and its differential diagnostic considerations

Abstract

T-cell prolymphocytic leukemia (T-PLL) is a rare T-cell leukemia characterized in many patients by marked peripheral lymphocytosis, prominent splenomegaly, and skin lesions. The differential diagnosis is broad and includes other T-cell disorders presenting with similar clinical findings. This review addresses (a) the natural history, demographics, and genetic features of T-PLL; (b) clinical and pathologic differential diagnostic considerations; and (c) recent developments in the T-PLL literature relevant to laboratory professionals. K E Y W O R D S leukemia, morphology, T-cells

An unusual case of T‐cell prolymphocytic leukemia mimicking a cutaneous vasculitis

“…Evaluation of the bone marrow and skin biopsy specimens reveal cells with a similar morphology to those seen in the peripheral blood. Flow cytometry confirms a post‐thymic mature T‐cell population with negative expression of TDT/CD1A and positive expression of CD5, CD2, and CD7 17 . Most cases are CD52+ and CD4+/CD8— though nearly 25% of cases coexpress CD4 and CD8 17 .…”

“…In addition, negative serology for HTLV‐I/II ruled out the diagnosis of ATLL (most cases of ATLL are CD25+, whereas this is negative in T‐PLL) 15 . The morphology was also distinct from the classic granular cytoplasm of large granular cell leukemia and the gyrate cerebriform nuclei of Sézary syndrome and ATLL 17 . An immature T‐cell neoplasm like lymphoblastic lymphoma could be ruled out on the basis of the negative expression of immature markers 18 .…”

“…On rare occasions, the coexistence of both conditions has been reported 20 . T‐PLL classically has a male predominance with a median age at presentation of 61 years 1,17 . Patients with ataxia telangiectasia and Nijmegan breakage syndrome can present at a younger age 5 .…”

T‐cell prolymphocytic leukemia: Insidious onset followed by aggressive course with cutaneous involvement

“…T‐PLL is a rare aggressive, mature T‐cell neoplasm affecting mainly elderly adults or younger individuals with ataxia‐telangiectasia 1,2 . The disease commonly presents with a very high white blood cell count and involvement of BM, spleen, liver, and lymph nodes 1,2 .…”

“…T‐PLL is a rare aggressive, mature T‐cell neoplasm affecting mainly elderly adults or younger individuals with ataxia‐telangiectasia 1,2 . The disease commonly presents with a very high white blood cell count and involvement of BM, spleen, liver, and lymph nodes 1,2 . Cutaneous involvement is described in almost 30% of patients, with purpuric maculopapular or nodular lesions and rather common prominent facial involvement 3,4 .…”