A Rare Presentation of Muscle Involvement in Sarcoidosis: A Case Report

Background: Sarcoidosis can affect virtually any organ of the body, primarily the lungs, lymphatic system, skin or eyes, or a combination of these sites and it is characterized by the formation of non-caseating granulomas. Muscular involvement in sarcoidosis is usually asymptomatic or pauci-symptomatic, and its nodular form is exceptional. Observation: In this study, we report the case of a 36-year-old man who had been presenting with nodules in both calves for about two years which onset was progressive. These nodules were painless and deeply embedded in the gastrocnemius muscles. There were no functional complaints, and the general condition was preserved. The physical examination, especially at skin level was free of other clinical signs except the nodules. The PET-scan (positron emission tomography) revealed a few discretely hypermetabolic cervico-axillary lymph nodes and multiple bilateral mediastino-hilar adenopathies involving all lymph nodes, as well as multiple bilateral hypermetabolic pulmonary foci. Biopsy of accessory salivary glands (BASG) exhibited an epithelioid and gigantocellular granuloma without necrosis that confirm the diagnosis of systemic sarcoidosis. The search for another location, notably cardiac, ophthalmological, neurological, or renal, was negative. The respiratory function tests did not show any restrictive syndrome or abnormalities in the DLCO/VA ratio. It was therefore a systemic sarcoidosis with mediastino-pulmonary stage II, diffuse lymph node, splenic, and muscle involvement. Conclusion: This case shows the importance of BASG in the diagnosis of muscular sarcoidosis, in case of impossibility of performing a muscle biopsy.