Tuberculosis immune reconstitution syndrome (TB-IRIS) followed by recurring lymphadenitis up to 8 years post-antituberculous treatment.

We present the case of a patient with HIV and tuberculosis (TB) coinfection who initially developed paradoxical TB immune reconstitution inflammatory syndrome (TB-IRIS) post-antituberculous treatment and post-antiretroviral therapy initiation. Despite being managed effectively, lymphadenitis recurred as many as three times over the course of several years. Due to consistent culture-negative lymph node biopsies, the recurring lymphadenitis was eventually deemed inflammatory rather than microbiological recurrences. Cessation of anti-TB treatment led to symptom remission followed by a long asymptomatic period, corroborating the immunological nature of the episodes. However, 5 and 6 years after cessation of anti-TB treatment, respectively, lymphadenitis returned. In both instances, her symptoms regressed without treatment with anti-TB drugs. This case underscores the complexities of managing TB-IRIS and the necessity of differentiating between paradoxical TB-IRIS and other paradoxical reactions for appropriate treatment decisions. Recognition of such distinctions is crucial in guiding effective therapeutic interventions in TB-HIV coinfection scenarios.

Ectopic Cushing's syndrome from a corticotropin-releasing hormone-secreting medullary thyroid carcinoma: a rare pitfall of inferior petrosal sinus sampling.

Summary: This case report describes a rare presentation of ectopic Cushing's syndrome (CS) due to ectopic corticotropin-releasing hormone (CRH) production from a medullary thyroid carcinoma (MTC). The patient, a 69-year-old man, presented with symptoms of muscle weakness, facial plethora, and easy bruising. An inferior petrosal sinus sampling test (IPSS) demonstrated pituitary adrenocorticotrophic hormone (ACTH) secretion, but a whole-body somatostatin receptor scintigraphy (68Ga-DOTATOC PET/CT) revealed enhanced uptake in the right thyroid lobe which, in addition to a grossly elevated serum calcitonin level, was indicative of an MTC. A 18F-DOPA PET/CT scan supported the diagnosis, and histology confirmed the presence of MTC with perinodal growth and regional lymph node metastasis. On immunohistochemical analysis, the tumor cell stained positively for calcitonin and CRH but negatively for ACTH. Distinctly elevated plasma CRH levels were documented. The patient therefore underwent thyroidectomy and bilateral adrenalectomy. This case shows that CS caused by ectopic CRH secretion may masquerade as CS due to a false positive IPSS test. It also highlights the importance of considering rare causes of CS when diagnostic test results are ambiguous. Learning points: Medullary thyroid carcinoma may secrete CRH and cause ectopic CS. Ectopic CRH secretion entails a rare pitfall of inferior petrosal sinus sampling yielding a false positive test. Plasma CRH measurements can be useful in selected cases.