Aggressive blood cancer masquerades as primary ITP: Case report
An enlarged spleen helps clue doctors into hidden lymphoma in man, 77
Written by |
An elderly man initially thought to have primary immune thrombocytopenia (ITP), which occurs without an identifiable underlying cause, was later found to have a blood cancer that had triggered the autoimmune disorder, according to a case report.
After standard ITP treatments failed to improve his condition and doctors identified several features uncommon in primary ITP, including an enlarged spleen, further testing ultimately revealed diffuse large B-cell lymphoma (DLBCL), an aggressive blood cancer affecting immune B-cells, as the cause of his ITP.
“This case emphasizes the importance of early recognition of underlying malignancy in atypical or treatment-resistant presentations [of the disease],” researchers wrote.
The study, “Diffuse Large B-cell Lymphoma Initially Managed As Secondary Immune Thrombocytopenia: A Case Report,” was published in the Cureus Journal of Medical Science.
In most cases, ITP develops without a clear underlying cause
ITP occurs when the immune system mistakenly attacks and destroys platelets, the cell fragments that help blood to clot. The resulting low platelet counts, known as thrombocytopenia, can lead to symptoms such as easy bruising and prolonged or excessive bleeding.
In about 80% of cases, ITP develops without a clear underlying cause. This is known as primary, or idiopathic, ITP. In the remaining cases, ITP develops as a consequence of an underlying condition, such as an infection, another autoimmune disease, or a blood cancer. This form is called secondary ITP.
One such cancer is DLBCL. In some people, DLBCL may first appear with severe thrombocytopenia, making it easy to mistake for primary ITP, which could delay a correct diagnosis. Identifying secondary causes, such as a blood cancer, is particularly important because treatment should focus primarily on the underlying disease, with ITP therapies used as needed.
Diagnosis was not straightforward
In the case report, researchers in Istanbul described a 77-year-old man whose severe thrombocytopenia was initially treated as primary ITP before doctors discovered it was actually caused by previously undiagnosed DLBCL.
The man sought medical care after several weeks of worsening fatigue, unexplained weight loss, and easy bruising. On examination, he appeared pale and had multiple bruises. Doctors also found enlarged lymph nodes in his neck and armpits, along with a mildly enlarged spleen, or splenomegaly. Blood tests revealed extremely low platelet counts, as well as anemia, a shortage of hemoglobin (the protein that carries oxygen in red blood cells), and a low white blood cell count.
Because no clear cause was identified at first, doctors treated him with oral corticosteroids, a class of immunosuppressive medications, and intravenous immunoglobulin therapy, both standard first-line treatments for ITP.
Further testing provided important clues. A blood smear, a test in which a drop of blood is examined under a microscope, revealed changes suggesting the involvement of the bone marrow, the spongy tissue inside bones where blood cells are made. PET/CT scans also revealed enlarged lymph nodes throughout the body, an enlarged spleen, and abnormalities in the bone marrow. Together, these findings raised suspicion for advanced lymphoma.
”This case highlights the importance of considering occult lymphoma in patients with atypical or refractory thrombocytopenia, especially when associated with splenomegaly.
Even then, the diagnosis was not straightforward. Because the patient’s platelet count remained so low, doctors could not safely remove a lymph node for biopsy, and the first bone marrow biopsy failed to provide a definitive diagnosis. The researchers noted that lymphoma can involve the bone marrow in a patchy pattern, meaning it may be missed on an initial biopsy.
Despite the inconclusive results, doctors remained suspicious that lymphoma was the underlying cause. After the patient received rituximab (sold as Rituxan in the U.S.) — an antibody therapy sometimes used for ITP — his platelet counts improved temporarily, allowing a second bone marrow biopsy to be performed. This time, the biopsy confirmed DLBCL.
The patient was then switched to R-mini-CHOP, a lower-dose version of a standard chemotherapy regimen often used in older adults with DLBCL. Over the following treatment cycles, his platelet counts returned to normal, his hemoglobin and low white blood cell counts improved, his fatigue and bruising resolved, and follow-up scans showed the lymphoma and enlarged spleen had markedly shrunk.
“This case highlights the importance of considering occult lymphoma in patients with atypical or refractory thrombocytopenia, especially when associated with splenomegaly,” the researchers wrote. They noted that splenomegaly is uncommon in primary ITP and should raise suspicion for a secondary cause such as lymphoma or another blood cancer.
The team also emphasized that an initially negative bone marrow biopsy should not rule out lymphoma when clinical suspicion remains high, underscoring the importance of repeating the procedure.
Leave a comment
Fill in the required fields to post. Your email address will not be published.