SUMMARY:With the use of high-resolution MR imaging techniques, we have increasingly observed anomalies of the hypothalamus characterized by a band of tissue spanning the third ventricle between the hypothalami, often without associated clinical sequelae. Historically, hypothalamic anomalies are highly associated with symptoms referable to a hypothalamic hamartoma, midline congenital disorder, hypothalamic-pituitary dysfunction, or seizures, with very few asymptomatic patients reported. The interhypothalamic tissue described in our cohort was observed incidentally through the routine acquisition of high-resolution T1WI. No referable symptoms were identified in most of the study group. In the appropriate patient population in which associated symptoms are absent, the described hypothalamic anomalies may be incidental and should not be misdiagnosed as hypothalamic hamartomas. ABBREVIATIONS:GMH ϭ gray matter heterotopia; IHA ϭ interhypothalamic adhesion

Pyogenic granuloma gravidarum is a benign fibrovascular proliferative lesion usually involving the oral gingivae in pregnant patients. While it also occurs, although less frequently, on other oral sites such as lips, tongue and palate, it is relatively unusual to find it in the nasal cavity. Furthermore, lesions normally involute spontaneously after childbirth. For persistent lesions requiring surgical management, imaging has historically been limited to CT. This case is notable not only for its uncommon location but also for its recurrent nature, failure to regress post partum and the use of MRI in the preoperative planning.

A s indicated in our article, 1 approximately 70% of our patients with interhypothalamic adhesions had no symptoms referable to hypothalamic-pituitary dysfunction (40 of 57). We have since identified 72 additional patients, of whom 51 had no clinical symptoms. Thus, in the appropriate patient population in which associated symptoms are absent, interhypothalamic adhesions may be incidental. Furthermore, in our experience, none of the asymptomatic patients and only 4 of the symptomatic population had additional midline abnormalities. We re-reviewed the imaging in all of our patients and found the numbers to hold true. None of the patients used for the figures had hypogenesis of the splenium or posterior periventricular white matter volume loss to cause splenium volume loss. The patient in Fig 1D did have a cavum septum pellucidum, a normal variant, but did not have partial fenestration on review of the images in 3 orthogonal planes. Last, we agree with the Whitehead and Vezina 2 thesis that "the midline should be closely scrutinized for additional anomalies/ abnormalities in patients harboring an interhypothalamic adhesion. Only after the brain has been carefully examined and signs/symptoms have been carefully considered can an interhypo-thalamic adhesion be considered an incidental and isolated finding." 3 It mirrors ours, "While associations between IHAs [interhypothalamic adhesions] and other syndromes likely exist, in the appropriate patient population lacking referable symptoms and with few or no other structural abnormalities, interhypothalamic adhesions may be incidental and of no clinical significance."