Merkel Cell Carcinoma of the Left Cheek With Testicular Metastasis: An Uncommon Occurrence.

Merkel cell carcinoma (MCC) is an infrequent and aggressive neuroendocrine tumor of the skin. 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) is an effective imaging technique with good diagnostic accuracy that may be used to help stage MCC and for detecting unexpected recurrences and distant metastatic disease. Other causes of testicular neoplasms, such as primary testicular tumors, lymphomas, or anaplastic small cell melanomas, are difficult to differentiate from MCC testicular metastases on imaging, and tumor markers and histopathology will help confirm it. The current case is a 65-year-old non-immunocompromised male with Merkel cell carcinoma who was incidentally identified with testicular metastases on PET/CT and confirmed on histopathology.

Insight Into the Ontogeny of GnRH Neurons From Patients Born Without a Nose.

CONTEXT: The reproductive axis is controlled by a network of gonadotropin-releasing hormone (GnRH) neurons born in the primitive nose that migrate to the hypothalamus alongside axons of the olfactory system. The observation that congenital anosmia (inability to smell) is often associated with GnRH deficiency in humans led to the prevailing view that GnRH neurons depend on olfactory structures to reach the brain, but this hypothesis has not been confirmed. OBJECTIVE: The objective of this work is to determine the potential for normal reproductive function in the setting of completely absent internal and external olfactory structures. METHODS: We conducted comprehensive phenotyping studies in 11 patients with congenital arhinia. These studies were augmented by review of medical records and study questionnaires in another 40 international patients. RESULTS: All male patients demonstrated clinical and/or biochemical signs of GnRH deficiency, and the 5 men studied in person had no luteinizing hormone (LH) pulses, suggesting absent GnRH activity. The 6 women studied in person also had apulsatile LH profiles, yet 3 had spontaneous breast development and 2 women (studied from afar) had normal breast development and menstrual cycles, suggesting a fully intact reproductive axis. Administration of pulsatile GnRH to 2 GnRH-deficient patients revealed normal pituitary responsiveness but gonadal failure in the male patient. CONCLUSIONS: Patients with arhinia teach us that the GnRH neuron, a key gatekeeper of the reproductive axis, is associated with but may not depend on olfactory structures for normal migration and function, and more broadly, illustrate the power of extreme human phenotypes in answering fundamental questions about human embryology.

Cardiac uptake patterns in routine 18F-FDG PET-CT scans: A pictorial review.

Broad variability of 18F-Fluoro-2-deoxyglucose (FDG) uptake is noted in myocardium while performing FDG PET-CT scans for viability, infection, or oncologic purposes. While most of the uptakes are considered non-specific, presence of underlying cardiac disease is seldom encountered. With this presentation, our intent is to pictorially highlight the variable FDG uptake patterns associated with the normal variations, benign, and malignant disease.

Congenital Arhinia: A Rare Case Report and Review of Literature.

Congenital absence of nose (Arhinia) is extremely rare. A male baby was born at term via uncomplicated vaginal delivery and presented with complete arhinia, bilateral microphthalmia, lower eyelid coloboma and feeding difficulty. Reconstructive surgery was postponed until preschool age. On follow up at 1 year of age baby is feeding liquid and semisolid food and growing well.