Corticosteroid Responsive Sarcoidosis with Multisystemic Involvement Years after Initial Diagnosis: A Lymphoma Mimicker on 18-FDG PET/CT

FDG-PET Scan in Sarcoidosis: Clinical and Imaging Indications

BACKGROUND

Sarcoidosis is an unknown etiology multisystem inflammatory disease in which noncaseating granulomas (a collections of inflammatory cells) form and grow in various organs, involving predominantly lungs, intrathoracic lymph node, skin and eyes. It most commonly affects patients between 20 and 40 years old of age but it could be observed at any age (female predominance; rare in Asians).

DISCUSSION

The areas of the body usually affected by sarcoidosis are lungs, skin, or lymph nodes; pulmonary and mediastinal involvement is seen in over of 90% of patients. Less commonly eyes, liver, heart, and brain are involved. Any organ, however, can be affected. Early diagnosis of sarcoidosis can be difficult due to few signs and symptoms in its early stages, and when disease does occur, it may mimic other pathologies, and is made up with chest X-ray, Computed Tomography (CT)-High Resolution CT (HRCT), gallium scans. Fluoro-Deoxy Glucose- Positron Emission Tomography (FDG-PET) is another useful tool to assess the extent of disease and has a potential to evaluate the clinical management of patients responding or not to the treatment.

CONCLUSION

In this review, we would summarize in brief the clinical indications of PDG-PET in sarcoidosis and report the imaging features of the main organs involved in this disease.

"The Great Mimicker": An Unusual Etiology of Cytopenia, Diffuse Lymphadenopathy, and Massive Splenomegaly

Sarcoidosis is an idiopathic multisystem disease characterized by the formation of noncaseating granulomas. It frequently presents with pulmonary infiltrates and bilateral hilar and mediastinal lymphadenopathy. Splenic involvement is common, but massive splenomegaly is a rare occurrence. Sarcoidosis is known as "the great mimicker" (or "the great imitator") since it exhibits a myriad of symptoms, mimicking other inflammatory, infectious, and neoplastic conditions, including lymphoma. Herein, we report the case of a 44-year-old male patient who was found to have bicytopenia, hypercalcemia, diffuse lymphadenopathy, and massive splenomegaly, a constellation of findings suggestive of underlying lymphoma. Interestingly, lymph node biopsy showed noncaseating granulomas suggestive of sarcoidosis, without evidence of malignancy.