The spectrum of coincident entities with small lymphocytic lymphoma/chronic lymphocytic leukemia (SLL/CLL) diagnosed by cytology

Abstract

Background: The cytologic diagnosis of Small lymphocytic lymphoma/chronic lymphocytic leukemia (SLL/CLL) often relies on finding a small lymphoid population with the characteristic immunoprofile by ancillary testing. There are only a few reports of other processes identified with SLL/CLL. The aim of this study was to review the fine needle aspiration (FNA) and touch prep (TP) diagnoses of SLL/CLL in order to identify any coincident entities.

Materials and methods: We retrospectively reviewed all FNA and TP cytology cases between January 2005 and May 2009 with a diagnosis of SLL/CLL to determine the presence of any coincident process.

Results: We identified 29 cases, including 23 FNAs and six TPs, from 23 patients. Ancillary studies were utilized in 97% of the cases, including flow cytometry (FC, 79%), immunohistochemistry (IHC, 55%), fluorescent in situ hybridization studies (24%) and special stains (7%). Coincident entities were identified in nine cases (31%) and included seven (28%) neoplastic entities (Hodgkin lymphoma [HL], adenocarcinoma, squamous cell carcinoma, seminoma) and two (7%) non-neoplastic entities (infection and immunoglobulin containing cells). Six cases (21%) suspicious for large cell transformation were also identified.

Conclusion: In our review of SLL/CLL, coincident entities were present in 31% of the cases and included a spectrum of non-neoplastic and neoplastic processes. FC was the most frequently utilized ancillary test, but IHC provided important information by excluding a mantle cell lymphoma or confirming a coincident process. Thus, cytomorphologic evaluation in these patients is important due to the high risk of a coincident process that may not be apparent by FC alone and may require clinical management.

Keywords: Chronic lymphocytic leukemia; SLL/CLL; cytopathology; small lymphocytic lymphoma.

Figure 1

Mycobacterial infection involving a lymph node involved with SLL/CLL. A&B. In a background of lymphoma, the FNA showed histocytes (a. arrow) and granulomas b) with the negative image of mycobacteria on DQ stained smears (A. DQ, ×400; B. DQ, ×600). c) An AFB stain performed was positive for acid fast bacilli (AFB, ×400)

Figure 2

Immunoglobulin-rich histiocytic cells (crystal storage histiocytosis) in a lymph node involved with SLL/CLL. The touch prep of a mediastinal LN demonstrated histiocytic cells with abundant cytoplasm containing dense material and cracking in a background of monomorphic lymphocytes. The corresponding histology (inset) of the LN showed SLL/CLL with similar cells containing immunoglobulin, as confirmed by immunohistochemical stains (TP, hematoxylin and eosin [H&E], ×400; inset, histology, H&E, ×400)

Figure 3

Non-lymphoid malignancies with SLL/CLL. a) Squamous cell carcinoma with SLL/CLL in a LN (fine needle aspiration, Diff-Quik™ [DQ], ×600). b) Adenocarcinoma of the lung with parenchymal lung involvement by SLL/CLL (touch prep [TP], hematoxylin and eosin [H&E], ×400; inset, corresponding histology, H&E, ×400), c) anaplastic seminoma with SLL/CLL in a mediastinal LN (TP, DQ, ×400; inset, corresponding histology, H&E, ×400)

Figure 4

Hodgkin lymphoma arising in a background of SLL/CLL. a) The LN demonstrated several Reed-Sternberg cells (arrow) in a background of a small homogeneous lymphoid population with scattered eosinophils (arrowhead) (Diff-Quik™ [DQ], ×400). b) Immunostains confirmed the impression of Hodgkin’s lymphoma (CD30 immunostain, X200) and FC confirmed the presence of SLL/CLL. c) Histology of LN involved by HL and SLL/CLL (hematoxylin and eosin, X200)

Figure 5

Cytomorphology of SLL/CLL case with large cells suspicious for transformation and histologic follow-up. a) Fine needle aspiration of right axillary LN with large cells suspicious for transformation (Diff-Quik™, × 400). The large cells are approximately 2–2.5× the size of the adjacent red blood cells, with prominent large nucleoli, in a background of the small lymphoid cells characteristic of SLL/CLL. b) The follow-up bone marrow biopsy (hematoxylin and eosin, ×400) was involved by SLL/CLL and also showed large cells with similar features, which were worrisome for an incipient transformation. The peripheral blood also showed an increase in prolymphocytes