Cushing's syndrome due to atypical carcinoid of the mediastinum

Ectopic Cushing's syndrome, caused by a neuroendocrine tumor (NET), is a rare finding. NETs of the mediastinum are extremely rare. NETs arising from the anterior mediastinum are generally aggressive. They are widely characterized at clinical presentations, and may be asymptomatic or present with atypical symptoms. Prognosis is often poor due to their local recurrence and distant metastasis despite a multimodal approach. A 33-year-old male patient was admitted to our department with a femoral soft tissue abscess, diabetes, and hypokalemia. He had no typical features of Cushing's syndrome. However, with a few simple tests, that is, a basal hormone profile, and low-dose and high-dose dexamethasone suppression tests, we diagnosed this complicated condition of ectopic adrenocorticotrophic hormone (ACTH) secretion. Thoracic computed tomography revealed an anterior mediastinal mass of 35 × 22 mm. A surgical excision of the tumor was proposed, and intra-operative pathology consultation returned positive for the suspected NET. Immunohistochemically, the tumor cells were positive for CK, CD56, Chromogranin, Synaptophysin, S100, and CD117. No thymic tissue was found. The Ki-67 was 4%. A diagnosis of primary NETs of the mediastinum, intermediate grade (G2), of atypical carcinoids according to WHO 2015 was established. This patient survived with no sequelae, no distant metastasis, no recurrence, and without adjuvant radiotherapy or chemotherapy 2 years after surgery thanks to earlier diagnosis and prompt surgical intervention. Mediastinum ectopic ACTH-secreting tumors are a rare type of cancer. According to recent research, these tumors frequently display more aggressive behavior and are linked to endocrinopathies. It is noted that patient might have a better outcome and a longer survival time due to earlier detection and complete resection of malignancies

Deficient anterior pituitary with common variable immune deficiency (DAVID syndrome): a new case and literature reports

Deficient anterior pituitary with common variable immune deficiency (DAVID) syndrome is a rare condition characterized by adrenocorticotropic hormone (ACTH) deficiency and primary hypogammaglobulinemia. It is due to heterozygous mutations of the nuclear factor kappa-B subunit 2 (NFKB2) gene. Only a few isolated cases have been reported since its first description by our team. Through the international multicenter GENHYPOPIT network, we identified a new case of DAVID syndrome. We then conducted an extensive review of the DAVID syndrome cases published from 2012 to 2022. A 7-year-old boy was diagnosed with symptomatic hypoglycemia revealing ACTH deficiency. Laboratory tests showed asymptomatic hypogammaglobulinemia. He harbored a heterozygous point mutation in NFKB2 gene (c.2600C > T, p.Ala867Val). His management included hydrocortisone replacement treatment, and he also received subcutaneous immunoglobulins during the Covid-19 pandemic. We analyzed 28 cases of DAVID syndrome with ACTH deficiency. ACTH deficiency was the only hormone deficiency in 79% of patients, but some patients harbored growth hormone (GH) and thyroid stimulating hormone (TSH) deficiencies. The first presenting symptoms were sinus/pulmonary infections (82%, mean age of 3 years) and alopecia (mean age of 4.7 years). ACTH deficiency was the third presenting condition (mean age at diagnosis of 8.6 years). All patients had hypogammaglobulinemia (decreased IgA and IgM levels), and 57% of patients had at least one autoimmune manifestation. Heterozygous mutations at the 3′end of the NFKB2 gene, coding for the C-terminal domain of the protein, were identified in all cases. Better knowledge of DAVID syndrome will help clinicians make an early diagnosis to avoid life-threatening complications