Two cases of dermatomyositis associated with neuroendocrine tumors.

Dermatomyositis is an idiopathic inflammatory myopathy with cutaneous manifestations, which is associated with several types of malignancies, yet it has been rarely linked to neuroendocrine tumors (NETs). Here we report two cases of dermatomyositis associated with NETs of differing primary sites. Case 1: A 46-year-old female presented with a facial rash and proximal muscle weakness of both extremities. Investigations revealed elevated creatine kinase (CK) and positive anti-transcriptional intermediary factor 1-γ antibody (TIF1γ). The patient had been diagnosed with dermatomyositis and underwent a total body CT scan, which revealed prominent mediastinal lymphadenopathy, which a subsequent biopsy determined to be neuroendocrine carcinoma of small cell type. Treatment with high-dose corticosteroids was initiated, in addition to chemotherapy-based oncological management. Case 2: A 54-year-old female presented with a facial rash, progressive dyspnea, and general malaise. Laboratory investigations revealed positive anti-melanoma differentiation-associated gene-5 (MDA5) and positive anti-Ro antibody, with a normal level of creatine kinase (CK). A chest CT scan revealed multiple ground-glass opacities. Despite treatment with high-dose intravenous methylprednisolone, IVIG and an infusion of the anti-IL-6 sarilumab [Kevzara], the patient rapidly deteriorated and was intubated. Within days, the patient developed bowel ischemia and underwent a laparotomy which was then complicated by an invasive infection. This resulted in patient's death. Pathology results from colonic tissue demonstrated an appendiceal neuroendocrine tumor. These cases demonstrate the heterogeneity and complexity of dermatomyositis in association with neuroendocrine tumors.