Sarcoidosis Induced by Atezolizumab Presenting With Xanthelasma Infiltration

We report a patient who developed specific lesions of sarcoidosis infiltrating some xanthelasmata 6 months after starting treatment with atezolizumab. A 69-year-old woman was referred to the dermatology department for infiltration of xanthelasmata. The patient was being treated with atezolizumab for metastatic uterine carcinosarcoma. Cutaneous biopsy from an infiltrated xanthelasma and from still yellow, no infiltrated xanthelasma showed differing proportions of foamy histiocytes and sarcoid granulomas. On physical examination, erythemato-marronaceous papules clustered on both knees, and not previously detected by the patient, were observed. The biopsy showed sarcoid dermal granulomas with foreign bodies. A chest computerized tomography scan was consistent with intrathoracic involvement of sarcoidosis. Endobronchial ultrasound-guided transbronchial needle aspiration of a mediastinal lymphadenopathy showed epithelioid cell granulomas. Histopathologically, the foamy histiocytes of xanthelasma seem to be replaced by or evolve to epithelioid cells to form sarcoid granulomas. The possible pathogenic mechanism is discussed. Dermatologists and dermatopathologists should bear in mind that sarcoidosis can present as infiltration of pre-existing xanthelasmata.
Source: The American Journal of Dermatopathology - Category: Pathology Tags: Extraordinary Case Report Source Type: research