Sarcoidosis lymphoma syndrome - the value of PET-CT in the diagnosis

Abstract

We report a 52-year-old patient who developed B-cell non-Hodgkin’s lymphoma subsequent to sarcoidosis. Sarcoidosis was diagnosed 16 years ago and remained asymptomatic for 14 years after steroid treatment. She presented with new symptoms of arthralgia, photosensitivity, butterfly erythema, autoimmune antibodies (ANA, chromatin positivity) associated with progression of the known left upper lobe lesion on the chest X-ray suggesting primary autoimmune disease (systemic lupus erythematosus). As steroid treatment was not effective, we started bolus cyclophosphamide therapy after which progression was seen on the chest X-ray. Computed tomography (CT)-guided needle biopsy confirmed malignancy of indefinable origin. Despite of the well-known fluorodeoxyglucose (FDG) avidity in active sarcoidosis, a FDG-positron emission tomography (PET) scan was performed to stage the primary tumour. Intensive FDG uptake was detected in the affected lung segment, with moderate uptake in mediastinal lymph nodes. The patient underwent left upper lobectomy. The histology showed pulmonary mucosa-associated lymphoma (bronchus-associated lymphoid tissue (BALT) lymphoma) in the lung tissue, while only sarcoidosis was present in the mediastinal lymph nodes. Bone marrow biopsy was negative.The association between sarcoidosis and lymphoma is known as sarcoidosis lymphoma syndrome, which is a rare disease. PET-CT was helpful in the differentiation of sarcoidosis and malignancy in this patient. It is important to be aware of the risk of lymphoma in sarcoidosis and FDG-PET, used for adequate purpose, can help the diagnosis.

PET/CT findings in sarcoidosis: Analysis of 53 cases

“…Çalışmamızda yüksek FDG tutulumlarına rağmen, CD4/CD8 oranı da sarkoidozda beklenin aksine düşük ortalama 3.4 (0.7-7.8) ve BAL sıvısında lenfosit hakimiyeti bulunmuştur. Sarkoidoz ve lenfomanın her ikisi de PET/BT'de lenf nodunda artmış glukoz tutulumu gösterir ve PET/BT, sarkoidoz tanısı için histopatolojik doğrulama gerekliliğini ortadan kaldırmaz 16 . Lenf nodu biyopsisi, mediastinoskopi, VATS, akciğer biyopsisi doku tanısı için başvurulan diğer invaziv yöntemlerdir 1 .…”

Differentiation of sarcoidosis-lymphoma syndrome lesions: a case report on the use of two different positron emission tomography tracers

“…Aside from malignancy, infected and inflammatory tissues also accumulate FDG; this makes FDG PET less specific. Specificity of FDG PET may be increased when it is fused with CT images [ 5 , 6 ].…”

“…Although FDG PET/CT can evaluate disease activity of mediastinal lymphadenopathies and lung lesions due to sarcoidosis, differentiating these lesions from malignant lymphoma remains difficult. Therefore, combining FAMT and FDG during post-therapy PET/CT studies may enable differentiation between sarcoidosis and suspicious residual lymphoma lesions [ 2 , 5 ].…”

“…Since positron emission tomography (PET) with 18 F-fluorodeoxyglucose (FDG) is very sensitive for detecting malignant lesions, it is often used to evaluate the extent of malignancies. However, FDG is not only accumulated in malignant cells but also in granulomatous lesions, such as sarcoidosis, making it difficult to differentiate between the two lesions [ 2 , 5 , 6 ]. L-[3- 18 F]-α-methyltyrosine (FAMT) is an amino acid analog PET tracer that reversibly accumulates in cells through L-type amino acid transporter 1 (LAT1).…”

Sarcoidosis-Lymphoma Syndrome presenting by severe Cholestatic Hepatitis

“…In the majority of these reports; sarcoidosis was followed by lymphoma, and exceptionally both coexisting together [11]. By the second week of admission, follow up laboratory data showed persistence of high cholestatic parameters and further rise in serum ferritin (Table 1) Figures 1,2).…”