Widespread sarcoid-like reactions linked to kidney tumor in case
Such reactions 'very rare' outside a sarcoidosis diagnosis: Researchers
A 30-year-old man with renal cell carcinoma — a type of kidney cancer — developed sarcoid-like reactions in his spleen, liver, and lungs, which went away after the tumor’s removal, suggesting that such reactions arose from an unusual immune response against the tumor.
The man’s case was described in a report titled “Resolution of multiorgan sarcoid-like reaction after treatment of renal cell carcinoma,” which was published in BMJ Case Reports by researchers in the U.K., who noted that sarcoid-like reactions are not usually widespread, thus making this a very unusual occurrence.
Sarcoid-like reactions happen when small clumps of immune cells, called granulomas, form in the body. This is similar to what happens in sarcoidosis, a disease in which granulomas develop in multiple organs, causing a range of symptoms.
Unlike sarcoidosis, sarcoid-like reactions secondary to cancer are usually found near the tumor or in the lymph nodes close to the tumor. Thus, the researchers noted that the presence of sarcoid-like reactions in the “spleen, liver and other organs in the absence of systemic sarcoidosis is very rare.”
Kidney tumor found after man, 30, sought treatment for difficulty breathing
Their report details the case of the London-area patient, who was diagnosed with renal cell carcinoma, a type of cancer that begins in the lining of the small tubes in the kidney that filter the blood and remove waste as urine. The man had first sought treatment after having difficulty breathing.
Imaging studies revealed a lesion in the left kidney, along with non-specific, sarcoid-like lesions in the liver, spleen, and lungs. Despite biopsies to examine the affected tissues, doctors initially failed to offer a clear explanation for what could have caused such lesions to develop.
“I initially visited the hospital due to difficulty in breathing, but after a series of tests and scans, was found to have some lesions in my abdomen and chest,” the patient said in a note included as part of the report. “The exact diagnosis could not be made even after several specialist referrals and tests, which was very frustrating.”
After the tumor was surgically removed, doctors observed granulomas inside and around the tumor tissue. Follow-up images revealed that the sarcoid-like reactions in the spleen, liver, and lungs had nearly disappeared. This suggested that the granulomas were likely linked to the renal cell carcinoma.
“I was initially shocked at the diagnosis of kidney tumor as I did not have any related symptoms. However, later I felt grateful that it was diagnosed accidentally at an early stage and later completely removed,” the patient said. “I had a smooth recovery after my kidney surgery and … am doing well.”
The researchers hypothesized that because the immune system may recognize and react against a tumor, granulomas may form as a defense mechanism “against disease progression.” These granulomas are non-caseating, meaning they do not have dead tissue inside, unlike those caused by infections.
The team noted that these sarcoid-like reactions should not be mistaken as metastasis, the spread of cancer cells from the original tumor site to other parts of the body, and “warrants a biopsy if in doubt.”
After five years, the man remained free of cancer. “Our case supports the hypothesis that non-caseating granulomas of SLR [sarcoid-like reactions] could be a manifestation of an immunologically mediated [antitumor] response,” the researchers concluded.
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