Rare Case of Sarcoidosis in Spleen Diagnosed via Tissue Analysis

A rare case of sarcoidosis affecting only the spleen was successfully diagnosed using tissue analysis, after imaging scans and lab tests failed, a case study reported.

Sarcoidosis should be considered when multiple tumors in the spleen have been detected, the scientists recommended. 

The case study, “A rare case of isolated splenic sarcoidosis: A case report and literature review,” was published in the journal Molecular and Clinical Oncology.

Sarcoidosis is characterized by an overactive immune response that triggers the formation of small clumps of inflammatory immune cells — called granulomas — in different tissues and organs. The lungs are affected in up to 90% of cases, followed by the heart, eyes, and lymphatic system. 

Sarcoidosis affecting the spleen (splenic) is rare, accounting for 6.7% of all cases — and often, other organs are also involved. Guidelines to diagnose and treat isolated cases in which sarcoidosis affects only the spleen have not been established. 

Furthermore, as there are no specific radiological findings to identify granulomas in the spleen using computed tomography (CT) or magnetic resonance imaging (MRI) scans, additional approaches are needed, such as histological examination, which involves the microscopic analysis of tissues. 

Investigators at the National Defense Medical College in Japan reported the rare case of a 76-year-old woman diagnosed with sarcoidosis of the spleen following a splenectomy (surgical removal of the spleen) by histological methods, because attempts to diagnose using radiological images and laboratory tests failed. 

She had a past medical history of renal pelvic cancer seven years previously and breast cancer six years earlier, and had been undergoing follow-up. 

Two years before the splenectomy, CT scans revealed multiple poorly resolved tumors of the spleen. Additional scans at one year and seven months later showed a gradual increase in the size of these tumors. MRI scans were unable to identify the tumors.

Positron emission tomography (PET) scans, using a radioactively labeled compound called FDG, showed accumulation in the spleen, reflecting elevated glucose metabolism typically found in actively growing cancer cells. 

Based on lab tests results indicating elevated levels of LDH, a sign of tissue damage, and higher levels of soluble interleukin-2 receptor (sIL-2R), a biomarker for inflammation, the team suspected malignant lymphoma — cancer of the lymphatic system.

To confirm the diagnosis, a splenectomy (removal of the spleen) was performed. The patient recovered without incident and was discharged eight days after surgery. 

Histological examination of the organ revealed small and dense granulomas without a pattern characteristic of lymphoma. Additionally, microorganisms were not identified, and cell analysis did not support a diagnosis of malignant lymphoma. Postoperative lab test results showed no significant change in LDH or sIL-2R levels.

Based on these findings, isolated sarcoidosis of the spleen was confirmed without affecting her lungs, heart, or eyes. Over seven months of follow-up, there were no signs of sarcoidosis or renal or breast cancer recurrence.

To explain these results, the investigators suggested that “malignant tumors might affect the body’s immune system and be responsible for the development of sarcoidosis in the spleen.”

“To the best of our knowledge, there are only 11 cases of isolated splenic sarcoidosis in the literature,” the team wrote. “It was suggested that splenic sarcoidosis was more common in women, and that sweating, and weight loss were frequently identified as subjective symptoms.”

Spleen lesions can be examined by “obtaining tissues for histopathology,” through approaches that include biopsy and splenectomy, they added. “Sarcoidosis should be included in the differential diagnosis when multiple splenic tumors are detected and sarcoidosis might be associated with malignant tumors.”