Now You See, Now You Don't: A Case Of Spontaneous Regression of Pituitary Tumour

Spontaneous regression of paediatric pituitary lesions-report of 2 cases and literature review

OBJECTIVE

Pituitary lesions are rare in the pediatric population. They consist of a heterogenous group of neoplasms including pituitary adenomas (PA) and Rathke cleft cysts (RCC). Their natural history, management strategies, and long-term outcomes are mostly extrapolated from adult experience. Neurosurgical intervention may be necessary for large and/or symptomatic lesions. Of note, the likelihood of their spontaneous regression is uncommon. We report 2 interesting cases of such a phenomenon for these lesions and discuss our findings in corroboration with current literature.

METHODS AND RESULTS

Two cases of spontaneous regression of pituitary lesions observed on serial neuroimaging are described. Based on their clinical history and radiological characteristics, the working diagnoses were that of a non-functioning PA and RCC, respectively. A systematic search of relevant publications in the English language is performed in PubMed and Google Scholar. Our findings show that there are 14 reported cases (including 1 of our patients) of spontaneous regression of non-functioning PA with good outcomes. Pertaining to RCCs, the limited evidence suggests that the incidence of their spontaneous regression is approximately 30%, similar to what is reported in the adult population. A separate discussion on the possible differential diagnosis of lymphocytic hypophysitis is also highlighted.

CONCLUSION

Pediatric pituitary lesions may present with unpredictable natural histories, as highlighted in our case examples. We advocate an extended period of follow-up by a cohesive multidisciplinary team. In meantime, collaborative efforts should focus on the establishing clinical practice guidelines to optimize the management of pituitary lesions in children.

Resolution of pituitary microadenoma after coronavirus disease 2019: a case report

Background

This report describes the case of a patient whose pituitary microadenoma resolved after he contracted coronavirus disease 2019. To our knowledge, this is one of the first reported cases of pituitary tumor resolution due to viral illness. We present this case to further investigate the relationship between inflammatory response and tumor remission.

Case presentation

A 32-year-old man in Yemen presented to the hospital with fever, low blood oxygen saturation, and shortness of breath. The patient was diagnosed with coronavirus disease 2019. Past medical history included pituitary microadenoma that was diagnosed using magnetic resonance imaging and secondary adrenal insufficiency, which was treated with steroids. Due to the severity of coronavirus disease 2019, he was treated with steroids and supportive care. Three months after his initial presentation to the hospital, brain magnetic resonance imaging was performed and compared with past scans. Magnetic resonance imaging revealed changes in the microadenoma, including the disappearance of the hypointense lesion and hyperintense enhancement observed on the previous scan.

Conclusions

Pituitary adenomas rarely undergo spontaneous resolution. Therefore, we hypothesized that tumor resolution was secondary to an immune response to coronavirus disease 2019.

Glucocorticoid Receptor Antagonism Upregulates Somatostatin Receptor Subtype 2 Expression in ACTH-Producing Neuroendocrine Tumors: New Insight Based on the Selective Glucocorticoid Receptor Modulator Relacorilant

Somatostatin exhibits an inhibitory effect on pituitary hormone secretion, including inhibition of growth hormone and adrenocorticotropic hormone (ACTH), and it can have antisecretory and antitumor effects on neuroendocrine tumors (NETs) that express somatostatin receptors. Although the precise mechanism remains unclear, the finding that glucocorticoids downregulate somatostatin receptor subtype 2 (SSTR2) expression has been used to explain the lack of efficacy of traditional SSTR2-targeting analogs in patients with ACTH-secreting NETs. Glucocorticoid receptor (GR) antagonism with mifepristone has been shown to reverse the glucocorticoid-induced downregulation of SSTR2; however, the effects of GR modulation on SSTR2 expression in ACTH-secreting NETs, particularly corticotroph pituitary tumors, are not well known. The current study presents new insight from in vitro data using the highly selective GR modulator relacorilant, showing that GR modulation can overcome dexamethasone-induced suppression of SSTR2 in the murine At-T20 cell line. Additional data presented from clinical case observations in patients with ACTH-secreting NETs suggest that upregulation of SSTR2 via GR modulation may re-sensitize tumors to endogenous somatostatin and/or somatostatin analogs. Clinical, laboratory, and imaging findings from 4 patients [2 ACTH-secreting bronchial tumors and 2 ACTH-secreting pituitary tumors (Cushing disease)] who were treated with relacorilant as part of two clinical studies (NCT02804750 and NCT02762981) are described. In the patients with ectopic ACTH secretion, SSTR2-based imaging (Octreoscan and ⁶⁸Ga-DOTATATE positron emission tomography) performed before and after treatment with relacorilant showed increased radiotracer uptake by the tumor following treatment with relacorilant without change in tumor size at computed tomography. In the patients with Cushing disease who received relacorilant prior to scheduled pituitary surgery, magnetic resonance imaging after a 3-month course of relacorilant showed a reduction in tumor size. Based on these findings, we propose that GR modulation in patients with ACTH-secreting NETs upregulates previously suppressed SSTR2s, resulting in tumor-specific antisecretory and anti-proliferative effects. The effect of relacorilant on pituitary corticotroph tumors is being investigated in an ongoing phase 3 study (NCT03697109; EudraCT 2018-003096-35).