Clinical Pearls & Morning Reports
Published February 27, 2019
Prominent systemic symptoms, rapid progression, and asymmetric lymphadenopathy would all be highly unusual in chronic lymphocytic leukemia (CLL). Read the latest Case Records of the Massachusetts General Hospital here.
Q: How common is herpes simplex virus (HSV) lymphadenitis in CLL?
A: HSV reactivation in CLL is common. Although it usually results in localized skin ulcerations, it may be associated with more severe and widespread infection. However, clinically obvious HSV lymphadenitis in CLL is rare, with fewer than 40 cases reported. HSV lymphadenitis in CLL is most often detected unexpectedly when lymph node biopsy is performed to rule out Richter’s transformation.
Q: What is the standard treatment for HSV lymphadenitis?
A: The primary antiviral therapy for HSV infection is acyclovir or one of its derivatives, valacyclovir or famciclovir. Although controlled trials have shown that acyclovir and its derivatives are effective agents for the treatment of several HSV-associated conditions (e.g., encephalitis), data regarding the use of these agents for the treatment of HSV lymphadenitis are limited because of the rarity of this entity. Occasional cases of HSV lymphadenitis have resolved spontaneously, without antiviral therapy, and thus there is no standard treatment for this condition.
A: Richter’s transformation is a syndrome in which diffuse large B-cell lymphoma (DLBCL), or in rare cases classic Hodgkin’s lymphoma, arises in a patient with CLL. Most cases of DLBCL are directly clonally related to the underlying CLL and share the same immunoglobulin heavy-chain gene (IGH) rearrangement, but some cases are clonally unrelated to the underlying CLL and have a distinct IGH rearrangement. Richter’s transformation occurs in 2 to 9% of patients with CLL and is most likely to develop 2 to 4 years after the diagnosis of CLL, although it may occur at any time during a patient’s disease course. The development of a markedly elevated lactate dehydrogenase level in a patient with CLL who does not have associated hemolysis arouses concern about Richter’s transformation.
A: Lesions associated with CLL often have a level of FDG avidity that is at or slightly above the level in the liver, with some heterogeneity, whereas lesions associated with Richter’s transformation typically have a high level of FDG avidity. If Richter’s transformation is suspected in a patient with CLL, an FDG-PET scan is the preferred imaging study to visualize the most appropriate lymph node to target during an excisional or core biopsy, which is then performed to determine whether Richter’s transformation is present.