B-cell Lymphomas May Underlie HLH Development in Rare Cases, Report Shows

B-cell Lymphomas May Underlie HLH Development in Rare Cases, Report Shows

Although rare, B-cell lymphomas may be the underlying cause of hemophagocytic lymphohistiocytosis (HLH), and complete remission may be achieved with chemotherapy regimens containing etoposide and steroids, a case report finds.

The study, “A rare case of diffuse large B-cell lymphoma-associated hemophagocytic lymphohistiocytosis,” was published in the Journal of Oncology Pharmacy Practice.

HLH is characterized by excessive inflammation and organ damage due to an overactivation of the immune system. The disease is considered primary when it appears as a result of genetic mutations, but a significant portion of HLH cases are triggered by conditions like infections, cancer, or autoimmune disease, and are considered secondary HLH.

Secondary HLH has been associated with lymphoma, but these were mostly T-cell lymphomas. Only in rare cases has HLH been found in patients with B-cell lymphoma.

Researchers at the University of Health Sciences, Turkey, reported the case of a 32-year-old man who was eventually diagnosed with HLH as the first symptom of a diffuse large B-cell lymphoma (DLBCL).

Initially, the man went to the hospital complaining of vomiting, nausea, and diarrhea. He was given antibiotics, but went to another hospital after three days because he was not urinating.

After blood tests showed elevated calcium levels, the patients was admitted to the hospital for dialysis treatment and a bone marrow exam later found signs of hemophagocytosis — when certain immune cells become over-activated and start eating up other blood and immune cells.

Additional analysis found that the patient fulfilled six of eight diagnostic criteria for HLH, which included fever, enlarged spleen, hemophagocytosis in bone marrow, elevated triglycerides (a type of fat molecule), low hemoglobin and platelets, and high ferritin levels.

The patient also had an H-score — a tool for diagnosing HLH — greater than 250, reflecting an over 99% probability of HLH syndrome. This prompted the initiation of an HLH treatment protocol with immunosuppressive medications and the chemotherapy etoposide.

To find out what was causing the HLH syndrome, researchers conducted several imaging exams to the brain, thorax, and abdomen, which showed only the spleen and liver enlargement characteristic of HLH. No signs of infection were detected, and no changes were seen in lymph nodes, a hallmark of lymphoma. DLBCL was diagnosed after a biopsy of the bone marrow.

Treatment was then switched from the HLH-2004 chemotherapy protocol to a lymphoma chemotherapy regimen called R-EPOCH, which consists of rituximab, etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin.

After three cycles of this chemo regimen, the patient was in complete remission, which was confirmed with a bone marrow biopsy and positron emission tomography-computerized tomography scan.

“Compatible with literature knowledge, our patient had responded very well to etoposide-containing regimens,” the researchers wrote.

Overall, this case report shows that the presence of B-cell lymphoma should be kept in mind when HLH is diagnosed, despite the rare association between these two conditions.

“In conclusion, herein, we have reported a DLBCL case that had presented with HLH, and clinicians should be aware that B-cell lymphomas may be the underlying cause of HLH,” the team concluded.