Pareidolia in neuroendocrinology: A pituitary macroadenoma resembling "Big Bird"

Context: Pareidolia is the imagined perception of a pattern, where it does not actually exist, as faces.
Case Description: a 49-year-oldwomanpresented with a pituitary macroadenoma with supra- and parasellar expansion containing two hypodense areas and one hyperintense area. On the T1W magnetic resonance imaging picture, this macroadenoma closely resembled a famous character from a children’s television series.
Conclusion: The imaging-phenotype in this case demonstrates that pareidolia can also be observed in neuroendocrinology and neuroradiology.

Pareidolia is the imagined perception of a pattern or meaning where it does not actually exist, like interpreting random images or patterns of light and shadow as faces. A well-known example of pareidolia is the “man in the moon”. Another nice example of pareidolia in medicine was given by Copsey, showing a brain magnetic resonance imaging (MRI) picture with the suggestion of the Virgin Mary.
In a study by Hadjikhani et al using magnetoencephalography, it was shown that objects perceived as faces evoked an early activation of the fusiform face area in the brain at a time and location similar to that evoked by faces, whereas other common objects did not evoke such activation. Voss et al, studying behavioral and functional magnetic MRI data, showed that during a recognition memory test, performance was associated with increased frontoparietal brain activity, regardless of meaningfulness. In contrast, neural conceptual priming effects for meaningful shapes occurred during both priming and recognition testing.
A 49-year-old woman presented with bitemporal visual field defects and loss of visual acuity in the left eye. She had recently experienced short periods of headaches. There was no galactorrhea. Laboratory examination demonstrated hypopituitarism, and serum prolactin was slightly increased above the upper limit of the reference range. The T1W MRI of the brain in the coronal plane displayed a pituitary macroadenoma with supra- and parasellar expansion containing two hypodense (cystic?) areas and one hyperintense (old hemorrhage?). The black-and-white image of the pituitary tumor closely resembles the famous “Big Bird” from “Sesame Street”.
The patient underwent successful pituitary surgery for a chromophobe, clinically nonfunctioning/nonsecreting pituitary adenoma after the start of pituitary hormonal replacement therapy. Postoperatively the visual defects had normalized completely.