The Pit, a Pendulum: Nelson–Salassa’s Syndrome Manifesting as Pituitary Carcinoma

Background Nelson–Salassa’s syndrome (NSS) is a sequela of severe Cushing’s disease (CD) that arises in the wake of bilateral adrenalectomy (ADX), a definitive but potentially morbid treatment for refractory hypercortisolism. Although classically described as visual loss and cutaneous hyperpigmentation attributable to the rapid growth of an ACTH-secreting adenoma following the removal of negative feedback, radiographic NSS has been described in up to half of CD patients after ADX, and typically follows a mild, asymptomatic course that rarely requires treatment. Notwithstanding, in its most pronounced forms, NSS remains a formidable and potentially life-threatening condition. We describe a case of highly morbid NSS, with comorbid malignant transformation into pituitary carcinoma.

Methods Case report.

Results A 44-year-old man with a history of severe, refractory CD underwent multiple treatments at an outside institution including two transsphenoidal resections, external beam radiotherapy, and bilateral ADX 4 years prior, after which he was lost to follow-up. He subsequently presented to our institution with worsening headaches, acute monocular vision loss, and progressive somnolence. MRI of the brain revealed marked enlargement of an invasive sellar and suprasellar lesion exerting significant mass effect on the chiasm ([Fig. 1A]–C); multiple new enhancing calvarial lesions were also noted ([Fig. 1D]). The patient was taken to the OR for emergent combined transsphenoidal optic apparatus decompression and open calvarial biopsy. Visual function was restored postoperatively, and pathologic analysis confirmed ACTH-immunoreactive pituitary carcinoma at both the sellar and calvarial lesions. Adjuvant therapy was initiated postoperatively with temozolomide.

Conclusion While NSS typically follows an indolent course, pituitary carcinoma is a highly morbid metastatic disease, and has been theorized to occur at a higher frequency in the NSS population. Close clinical follow-up and serial radiographic surveillance are recommended following bilateral ADX; although mild, asymptomatic NSS is more frequently observed, patients demonstrating rapid growth or new symptoms after bilateral ADX may require further treatment with stereotactic radiosurgery and/or repeat surgery. Furthermore, patients with multiple enhancing lesions or other features suspicious for pituitary carcinoma require immediate diagnostic and therapeutic interventions.

Fig. 1