Guess the Diagnosis: Case 1 - Episode 3
Dr. David Fajgenbaum, Perelman School of Medicine, University of Pennsylvania, says pathology alone cannot render a diagnosis of MCD. A diagnosis of MCD re- quires (a) the presence of pathology consistent with MCD; (b) exclusion of oth- er disorders, which can give rise to similar pathology; and (c) enlargement of multiple lymph node stations. EBV, lymphoma, and autoimmune disorders are especially important to rule out. Testing for these disorders was negative in this patient.
Next, it is crucial to establish whether or not the patient has active HHV-8 replication. This can be established by quantitative polymerase chain reaction (PCR) for HHV-8 on the peripheral blood, which can be ob- tained through large reference laboratories or academic centers that have an interest in MCD and other HHV-8related disorders. PCR for HHV-8 was negative in this patient. The other gold standard for assessing HHV-8 sta- tus is LANA-1 staining for the lymph node. There have been reports of cases with negative LANA-1 staining that had replicating HHV-8 by PCR. In addition, one should rule out HIV infection by serology. HHV-8 serology is not informative, because as approximately 10% to 20% of the US popu- lation have been in contact with the HHV-8 virus and are latently infected, but the virus is well controlled by their immune system.
Both HHV-8positive and HHV-8–negative patients with MCD can exhibit a spectrum of clinical features, ranging from mild flu-like symptoms to multi- organ failure. It is important to distinguish the two variants of MCD because they require different therapeutic approaches.
What other tests are important in her diagnostic workup?
Guess the Diagnosis: Case 1
Lisa B. is a 47-year-old female store owner from St. Louis, with a 10-month history of fatigue, night sweats, and weight loss.
Lisa’s pathology report shows the following findings:
In view of these findings, the hematologist orders further tests, which yield the following results: