Document Type

Conference Proceeding

Publication Date


Publication Title

J Gen Intern Med


CASE: Middle age female with a history of cerebral palsy and triple negative non-metastatic breast cancer of the left breast on three months of pembrolizumab therapy and status post localized lumpectomy and partial mastectomy presented with subacute lower back pain, decreased appetite, and bilateral lower extremity weakness. Patient previously ambulated with a walker but now was unable to ambulate. Physical exam was significant for intact sensation in all four extremities, intact cranial nerves, 3/5 strength on all lower extremity maneuvers bilaterally and 5/5 strength on all upper extremity maneuvers bilaterally. Venous dopplers, computed tomography (CT) of chest, CT of head, CT of cervical spine, and X-rays of lower extremities did not reveal any significant findings. Magnetic resonance imaging (MRI) of brain and whole spine showed degenerative changes in the spine with disc protrusion at C3-C4 and T8-T9. Spinal cord, conus medullaris, and cauda equina roots were otherwise normal. Random serum cortisol on admission was low with an otherwise unremarkable initial laboratory work up. Patient had positive cosyntropin stimulation test, consistent with adrenal insufficiency. Adrenocorticotropic hormone and dehydroepiandrosterone sulfate were also low. Findings suggested she had developed secondary adrenal insufficiency. Patient was started on a short-acting glucocorticoid, hydrocortisone, with two-thirds of the total dose in the morning and one-third in the afternoon to stimulate normal cortisol circardian rhythm per endocrinology recommendations and returned to baseline within days. Neurology workup including MRI was negative for neurologic cause for her symptoms. Oncology held pembrolizumab therapy and treated with radiation therapy. Although endocrinology eventually cleared resumption of pembrolizumab if necessary for breast cancer treatment, an alternative chemotherapy regimen was elected per patient and caregiver preference.

IMPACT/DISCUSSION: Adrenal insufficiency can have a variety of etiologies. Pembrolizumab-induced adrenal insufficiency is a rare immune-related adverse event. With treatment, patients can achieve a complete response with reversal of symptoms. Early recognition is essential in improving a patient's functional status and can be fatal if diagnosis is delayed given the possibility of adrenal crises.

CONCLUSION: Pembrolizumab chemotherapy can cause secondary adrenal insufficiency during treatment or late onset. Adrenal insufficiency can present with focal neurologic symptoms. Early identification and initiation of treatment will contribute to positive patient outcomes.



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