Although the presence of granulomatous reactions in patients with NHL is known, they have been rarely observed in CLL.
13,14,24 In our study group, all five patients with CLL became symptomatic as a result of a granulomatous process within the setting of their previously or newly (patients 1 and 2) diagnosed NHL. Three patients had sarcoid-like lesions, and sarcoidosis, and two suffered from mycobacterial infections.
Sarcoid-like lesions represent non-specific histological patterns that may be associated with viral infections, tuberculosis, sarcoidosis, or lymphoproliferative disorders, so that in addition to a careful histological examination, special stains and PCR analyses should be performed to exclude the presence of an infectious agent.
14,15 Although a distinction is made between sarcoid-like lesions and sarcoidosis, some evidence points to the possibility that sarcoidosis represents a generalised equivalent of sarcoid-like lesions that may be caused by phospholipids from necrotic material or chronic antigen stimulation.
20,25,26 In sarcoid-like lesions, putative (for example, tumour derived) antigens are thought to cause a hypersensitivity reaction mediated by T cells that stimulate monocytes to form an epithelioid granuloma.
2 Several authors noted the presence of both sarcoidosis and NHL in the same patient.
1,17,20,24,27 Chemotherapy may be one reason for the development of sarcoid-like lesions. So far, only IFNα is known to induce sarcoidosis/sarcoid-like lesions.
18,27 Continuous IFNα administration in viral infection can activate T cells and macrophages.
18 An accumulation of CD4
+ T cells has been seen in IFNα associated skin eruptions.
19 Indeed, in our study, one female patient with CLL developed fludarabine/IFNα resistant bihilar lymphadenopathy, with an increased angiotensin converting enzyme concentration (62 U/litre) and raised local CD4/CD8 ratio in the bone marrow sarcoid-like lesions, and therefore was diagnosed as suffering from sarcoidosis. Interestingly, all these symptoms, including the bihilar lymphadenopathy, resolved after withdrawing IFNα treatment. Kornacker
et al noted sarcoidosis in two patients with NHL without IFN treatment and made the intriguing suggestions of (1) a probable spread of an infectious agent during immunosuppression leading to granuloma formation, or (2) chemotherapy induced elimination of immunosuppressive cells that inhibit immune activation resulting in sarcoid-like lesion formation.
1Take home messages- Granulomatous reactions might obscure diagnosis in patients with undiagnosed small lymphocytic lymphoma/chronic lymphocytic leukaemia (CLL) or imitate disease progression and Richter’s transformation in those with known CLL
- Careful histological examination including special stains, exclusion of infectious agents by molecular techniques, and a detailed clinical history, including treatment with interferon α, are essential for a correct diagnosis
To date, sarcoid-like lesions have only rarely been seen in the lymph nodes and bone marrow of patients with CLL. Choe
et al investigated 372 cases of bone marrow granulomas and found no cases of CLL, whereas Bhargava and Farhi reported one case of CLL in 21 patients with haematological diseases associated with sarcoid-like lesions.
10,13 Marruchella
et al reported the case of a 59 year old woman with CLL treated with chlorambucil and fludarabine, who subsequently developed sarcoidosis with diffuse lung involvement and bihilar lymphadenopathy.
24 In our study, most of the patients with haematological neoplasms and concomitant granulomatous (especially sarcoid-like) lesions had CLL, perhaps in part because of the frequent occurrence and long clinical history of CLL, similar to that seen in testicular germ cell tumours.
24 However, studies on T cell function in CLL have revealed a wide range of abnormalities, including absolute CD8
+ lymphocytosis and abnormalities in ligand expression. The elimination of specific CD8
+ immunosuppressive cells and CD4
+ T helper type 1 and 2 cell subsets through chemotherapy might also contribute to sarcoid-like lesion formation.
1,28 Furthermore, treatment associated T cell dysfunction and subset disturbances in CLL, such as specific loss of CD4
+ helper cells—induced by alkylating agents, purine analogues, especially fludarabine, and steroids
29,30—lead to disturbed immune surveillance for infections, especially those caused by mycobacteria,
Listeria monocytogenes, pneumocystis,
Candida spp,
Aspergillus spp, cytomegalovirus, varicella zoster virus, and herpes simplex virus, all of which may trigger granuloma formation.
13–15,28 The treatment associated T cell dysfunctions in CLL result mainly from the fact that the therapeutic agents used inhibit not only lymphocyte RNA and DNA synthesis and repair, but also cytokine induced STAT1 activation, and interfere with the interleukin 2 cascade, which is essential for cell mediated immunity function.
30,31 Indeed, we found severe mycobacterial infections in two patients with CLL, one of whom unfortunately died of septicaemia. Clinically, both patients presented with a rapidly progressive generalised lymphadenopathy and lactate dehydrogenase increase, but low leucocyte counts, so that Richter’s transformation was clinically suspected, although the first histological examination detected mycobacteriosis.
In summary, symptoms caused by granulomatous reactions can occasionally lead to the detection of an otherwise dormant CLL or, in cases with known CLL, clinically mimic disease progression or treatment resistance. Treatment with IFNα, but also infections, especially mycobacterioses, and CLL related or treatment induced changes in lymphocyte communication may cause granulomatous reactions. Careful histological examination applying special staining procedures, combined with modern methods for molecular detection of infectious agents, considering also details of the clinical history, should lead to the correct diagnosis.