Sporadic Noradrenergic Adrenal Pheochromocytoma in an Adolescent Patient.

Pheochromocytoma and paraganglioma are neuroendocrine tumors that occur less commonly among children compared to adults. The excess catecholamines secreted by the tumor cells result in hypertension, tachycardia, excess sweating, and headache. Other symptoms include abdominal pain or distension caused by the adrenal mass. Here, we report a case of pheochromocytoma arising from the left adrenal medulla in a 14-year-old boy, which was exclusively secreting norepinephrine, as suggested by elevated plasma and 24-hour urinary norepinephrine and its metabolite normetanephrine. The epinephrine and its metabolite metanephrine were within normal limits. He presented with abdominal pain, recurrent vomiting, and headache and was noted to have elevated blood pressure. He underwent adrenalectomy after controlling his blood pressure with an alpha-blocker Prazosin. His blood pressure remained stable after surgery, and his plasma-free metanephrines returned to normal limits. He tested negative for hereditary paraganglioma-pheochromocytoma gene panel.

Endocannabinoid system acts as a regulator of immune homeostasis in the gut.

Endogenous cannabinoids (endocannabinoids) are small molecules biosynthesized from membrane glycerophospholipid. Anandamide (AEA) is an endogenous intestinal cannabinoid that controls appetite and energy balance by engagement of the enteric nervous system through cannabinoid receptors. Here, we uncover a role for AEA and its receptor, cannabinoid receptor 2 (CB2), in the regulation of immune tolerance in the gut and the pancreas. This work demonstrates a major immunological role for an endocannabinoid. The pungent molecule capsaicin (CP) has a similar effect as AEA; however, CP acts by engagement of the vanilloid receptor TRPV1, causing local production of AEA, which acts through CB2. We show that the engagement of the cannabinoid/vanilloid receptors augments the number and immune suppressive function of the regulatory CX3CR1hi macrophages (Mϕ), which express the highest levels of such receptors among the gut immune cells. Additionally, TRPV1-/- or CB2-/- mice have fewer CX3CR1hi Mϕ in the gut. Treatment of mice with CP also leads to differentiation of a regulatory subset of CD4+ cells, the Tr1 cells, in an IL-27-dependent manner in vitro and in vivo. In a functional demonstration, tolerance elicited by engagement of TRPV1 can be transferred to naïve nonobese diabetic (NOD) mice [model of type 1 diabetes (T1D)] by transfer of CD4+ T cells. Further, oral administration of AEA to NOD mice provides protection from T1D. Our study unveils a role for the endocannabinoid system in maintaining immune homeostasis in the gut/pancreas and reveals a conversation between the nervous and immune systems using distinct receptors.

Sinus histiocytosis with massive lymphadenopathy: complicated by autoimmune hemolytic anemia.

Sinus histiocytosis with massive lymphadenopathy is a rare histiocytic disorder with very few case reports in Indian literature. Immunological abnormalities have been documented in few cases. We report one such case of a child presenting with generalized lymphadenopathy and complicated by autoimmune hemolytic anemia, suggestive of an associated immune dysfunction.