Incidental chronic lymphocytic leukaemia in a biopsy of Merkel cell carcinoma

Primary cutaneous lymphomas in patients with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL): A series of 12 cases

BACKGROUND

Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) is associated with an increased risk of a second malignancy.

METHODS

We conducted a retrospective clinicopathologic review of 12 patients with CLL/SLL who developed a second lymphoma in the skin. Demographic data, clinical information, and histopathology from 31 biopsies were recorded. Cases of secondary cutaneous involvement by CLL/SLL (leukemia cutis) and non-primary cutaneous lymphomas were excluded.

RESULTS

A wide variety of primary cutaneous lymphomas was identified, including classic mycosis fungoides (3), cutaneous marginal zone lymphoma (2), primary cutaneous peripheral T-cell lymphoma unspecified (2), folliculotropic mycosis fungoides (1), Sézary syndrome (1), cutaneous gamma-delta T-cell lymphoma (1), cutaneous CD8+ aggressive epidermotropic cytotoxic T-cell lymphoma (1), and cutaneous anaplastic large cell lymphoma (1). A male predominance was observed, and the average age was 74.1 years. In all patients, CLL/SLL predated the development of the second lymphoma, which was aggressive in the majority of cases (58%). Aggressive cytotoxic T-cell lymphomas, generally rare neoplasms, were relatively common (30%).

CONCLUSIONS

CLL/SLL patients may develop a second lymphoma in the skin, which may be aggressive. Atypical cutaneous lymphoid infiltrates in this patient population should not be assumed to represent secondary CLL/SLL involvement and require thorough immunohistochemical analysis.

Composite Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma and T-Prolymphocytic Leukemia Presenting with Lymphocytosis, Skin Lesions, and Generalized Lymphadenopathy

Chronic lymphocytic leukemia (CLL) is the most common type of leukemia in Western countries with an incidence of 3-5 cases per 100,000 persons. Most patients follow an indolent clinical course with eventual progression and need for therapy. In contrast, T-prolymphocytic leukemia (T-PLL) is a rare type of T-cell leukemia with most patients having an aggressive clinical course and a dismal prognosis. Therapies are limited for T-PLL patients and there is a high relapse rate. Morphologically, the cells of CLL and T-PLL can show overlapping features. Here, we report the case of a 61-year-old man who presented with a clinically indolent CLL and T-PLL, initially diagnosed solely and followed as CLL, despite the presence of an associated but unrecognized aberrant T-cell population in blood. After 2 years, the T-PLL component became more apparent with cutaneous and hematologic manifestations and the diagnosis was confirmed by immunophenotypic and cytogenetic analysis. Fluorescence in situ hybridization demonstrated an ATM deletion in both CLL and T-PLL components. Retrospective testing demonstrated that composite CLL and T-PLL were both present in skin and lymph nodes as well as in blood and bone marrow since initial presentation. This case is also unique because it highlights that a subset of T-PLL patients can present with clinically indolent disease. The concomitant detection of ATM mutation in CLL and T-PLL components raises the possibility of a common pathogenic mechanism.

A unique case of concurrent chronic lymphocytic leukemia/small lymphocytic lymphoma and lymphomatoid papulosis in the same biopsy

Chronic lymphocytic leukemia (CLL/SLL) is the most common leukemia in the western world and its cutaneous dissemination a very uncommon phenomenon. Lymphomatoid papulosis (LyP) is a CD30+ lymphoproliferative disorder characterized by chronic, recurrent and self healing skin lesions. Up to 20% of patients with LyP have a coexistent lymphoma. While the association between the two entities has been reported, their coexistence has never been documented. We describe a 74-year-old man with known CLL and thrombocytopenia who presented with a 2 year history of recurrent nodules and plaques to both arms and legs that resolved within 4-6 weeks after administration of rituximab and bendamustin for his CLL treatment. His biopsies showed an atypical lymphoid infiltrate, composed of large and pleomorphic cells with a nodular and interstitial pattern in a background of eosinophils. Immunohistochemical staining revealed a pattern of two separate yet coexisting neoplastic processes; a large CD30 positive T-cell lymphoproliferative disorder, while the other one was diagnostic of a neoplastic B-cell process (leukemia cutis). A diagnosis of coexistent LyP and cutaneous involvement by CLL/SLL was rendered. The simultaneous presence of both disorders can be a pitfall in the differential diagnosis of large cell lymphomas, such as Richter's transformation of CLL/SLL.

Merkel cell carcinoma with partial B-cell blastic immunophenotype: a potential mimic of cutaneous richter transformation in a patient with chronic lymphocytic lymphoma

Merkel cell polyomavirus (MCPyV) is a DNA virus whose pathogenic mechanisms in Merkel cell carcinoma (MCC) are still being unraveled. Emerging reports of an association between MCPyV and chronic lymphocytic lymphoma (CLL) have begun to broaden our understanding of the oncogenic mechanisms of this virus and the known association between these 2 malignancies. Herein, we report a case of MCC demonstrating a B-cell immunophenotype arising in a patient with CLL being treated with rituximab. In this context, we discuss the differential diagnostic considerations, especially with cutaneous Richter transformation (diffuse large B-cell lymphoma). We also assessed for the presence of MCPyV in both the patient's MCC and the CLL. Finally, we provide a large meta-analysis of patients with CLL and MCC. Patients with both MCC and CLL have a dismal prognosis, with greater than 50% overall mortality within the first year and a half after MCC diagnosis.

Concurrent chronic lymphocytic leukemia and merkel cell carcinoma in primary skin tumor and metastatic lymph node

Association between chronic lymphocytic leukemia and other malignancies has been known for a long time. This epidemiological phenomenon is explained by immunosuppression caused by disease itself or by the applied therapy. Merkel cell carcinoma is a rare malignant tumor of the skin of neuroendocrine origin diagnosed almost exclusively in immunocompromised host. We presented an unique case of coexisting infiltration of chronic lymphocytic leukemia cells within primary cutaneous Merkel cell carcinoma and metastatic lymph node in young HIV-negative female patient.

Extramedullary chronic lymphocytic leukemia: systematic analysis of cases reported between 1975 and 2012

The prognostic significance of extra-medullary chronic lymphocytic leukemia (EM-CLL) is unknown. We conducted a Medline database systematic search analyzing English language articles published between 1975 and 2012 identifying 192 cases. Patients with EM-CLL were more commonly treated than not (p < .001). Skin and central nervous system (CNS) were the most commonly reported sites of organ involvement. Survival after diagnosis of EM-CLL appeared to depend on the site of EM involvement. Prospective evaluation and further studies of EM-CLL are warranted.