Morpheaform Sarcoidosis: A Case Presentation of an Uncommon
Sarcoidosis is a systemic granulomatous disorder of unknown etiology that can involve virtually any organ system. The most common sites affected include the lung, thoracic lymph nodes, eyes, heart, and central nervous system, with skin involvement in an estimated 20 to 35% of patients. The cutaneous manifestations of sarcoidosis are heterogeneous, but are broadly classified as ‘specific’ if they contain non caseating granulomas on histopathologic examination, or as ‘nonspecific’ if they lack this hallmark feature. Morpheaform sarcoidosis is one ‘specific‘ variant which can represent a particular diagnostic challenge. Due to its clinical resemblance to morphea, patients are often misdiagnosed as having localized scleroderma. Here authors describe a patient thought to have morphea but was later diagnosed with skin limited morpheaform sarcoidosis.

A 58-year-old African American female with no remarkable past medical history, including no history of diabetes or peripheral vascular disease, was referred to the Scleroderma clinic in Rheumatology division by her dermatologist for consideration of localized scleroderma (morphea). She had a plaque-like rash on her right lower leg which had been worsening over several years. Her dermatologist had biopsied the lesion and pathology was read as “consistent with scleroderma”. Upon presentation to our clinic, she reported darkened “tight” skin as well as muscle and bone pain deep to
the area of skin changes.

Physical exam demonstrated a tightly adherent, thickened, and hyperpigmented plaque over the right anterior shin. Laboratory findings were unremarkable, including a normal CBC with differential, CMP, ESR, and CRP. Her PPD was negative and pulmonary function testing (PFTs) demonstrated only mild obstruction. X-ray and CT scan of the chest were normal and she had no other evidence of systemic disease. X-rays of the right leg were unremarkable.

Due to muscle and bone pain deep to the cutaneous lesion, an MRI of the right leg was performed and revealed extensive, diffuse T2 signal hyperintensity involving the superficial and deep musculature and adipose layer concerning for inflammatory myositis or eosinophilic fasciitis. A full thickness biopsy including the fascia was performed and demonstrated an extensive granulomatous infiltrate extending throughout the subcutaneous tissue.

No central necrosis or caseation was seen and the granulomas were devoid of peripheral lymphocytes. Polarized light exam and special infectious stains were negative. Together, these changes were compatible with a diagnosis of sarcoidosis, and were not consistent with eosinophilic fasciitis, necrobiosis lipoidica, lipodermatosclerosis or morphea. A diagnosis of morpheaform sarcoidosis was thus made based on the clinical and histopathological findings.

She was treated with tapering oral prednisone, hydroxychloroquine and methotrexate and experienced improvement in her skin lesion and resolution of her muscle and bone pain. She has been followed for 8 years since her diagnosis and remains well controlled on hydroxychloroquine and methotrexate with no evidence of systemic sarcoidosis.

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