Rabbit Anti-Human ACTH monoclonal antibody, clone 0I6M8

Context. Truly, mixed corticomedullary adrenal tumors (MCATs) may not come from colliding tumors but from a single stem cell. Objective. To report the immunohistochemical and molecular evaluation of a patient with ectopic ACTH syndrome (EAS) from a MCAT which has single cells with features of both 96 medullary and cortical differentiation. Case Description and Methods. A 16-year-old woman presented with severe EAS and a large right MCAT composed of ACTH-secreting cells resembling pheochromocytoma and another lineage similar to adrenal carcinoma. Immunohistochemistry (IHC) showed positivity for medullary (ACTH, chromogranin A, synaptophysin, and PS-100) and epithelial components (inhibin, melan-A, and calretinin). Embryonic stem cell markers were evaluated using RT/PCR and immunofluorescence. After initial surgery, the tumor recurred shifting to rapidly progressive ACTH-independent liver metastasis. Results. Histopathology and IHC revealed two distinct and intermingled cellular patterns, while some cells immunostained for both medullary and cortical markers. Demonstration of all stem cell biomarkers by RT/PCR and immunofluorescence was predominantly localized to the nucleus, whereas SOX2 immunoreactivity was evident in the cytoplasm as well. Conclusion. The expression of cancer stem cell biomarkers points towards the involvement of primitive embryonic cells as the origin of this neoplasm and maybe to the clinically aggressive and biochemically changing behavior.

Nivolumab, an anti-programmed cell death-1 monoclonal antibody, is currently used to treat many types of advanced cancers including recurrent and metastatic head and neck cancer. However, there are increasing reports concerning immune-related adverse events related to nivolumab therapy. Here, we report three patients who presented with adrenal insufficiency following nivolumab therapy. Two were diagnosed as having isolated adrenocorticotropic hormone (ACTH) deficiency and one was diagnosed as having primary adrenal insufficiency. All three patients complained of progressive fatigue and appetite loss, so we measured their blood cortisol and ACTH levels and diagnosed them as having adrenal deficiency. Treatment with nivolumab was discontinued for all three patients, and replacement therapy using hydrocortisone was successful after a few days in all cases. Two patients subsequently resumed nivolumab therapy because their general condition had improved. Complaints of fatigue and appetite loss during cancer treatment are common and tend to be regarded as unimportant. Although adrenal insufficiency due to nivolumab is relatively rare, complaints of these symptoms could lead to the detection of adrenal insufficiency at an early stage. The present report highlights the importance of the early recognition of adrenal insufficiency. (C) 2019 Elsevier B.V. All rights reserved.