Orbital Metastasis: Rare Initial Presentation of an Occult Gall Bladder Carcinoma

The Isolated Humeral Metastasis as the Initial Presentation of Renal Cell Carcinoma Revealed by 18 F-FDG PET/CT

ABSTRACT

Renal cell carcinoma (RCC) with isolated humeral metastasis as the initial presentation is rare. We reported FDG PET/CT findings of isolated humeral metastasis from RCC in a 63-year-old man with right upper arm pain as the initial presentation. The bone scanning in an outside hospital showed that the focus with increased uptake of the right humerus was possibly malignant. FDG PET/CT showed that the right humeral mass had intense activity, and there was an additional FDG lesion in the lower pole of the right kidney. The mass of the right humerus was later confirmed as humeral metastasis from RCC by pathological examination.

The Humeral Metastasis as the Initial Presentation of Lung Adenocarcinoma Revealed by 18F-FDG PET/CT

ABSTRACT

Lung adenocarcinoma with humeral metastasis as the initial presentation is rare. We reported FDG PET/CT findings of solitary humeral metastasis from adenocarcinoma of the lung in a 57-year-old man with the right upper arm pain as the initial presentation. MRI showed bone destruction of the right humerus with a soft tissue mass, suggesting the possibility of malignancy. FDG PET/CT showed that the right humeral mass had strong activity, and there were additional FDG lesions in the right armpit, left apical lung, and left adrenal gland, which was later confirmed as humeral metastasis from lung adenocarcinoma by pathological examination.

Orbital and brain metastases on 68Ga-PSMA PET/CT in a patient with prostate carcinoma refractory to 177Lu-PSMA and 225Ac-PSMA therapy

We present a case of metastatic prostate cancer with rare metastases involving the brain and orbit, in addition to liver, skeletal and nodal metastases. The patient had undergone prior hormonal therapy and chemotherapy and had disease progression despite 2 cycles of ¹⁷⁷Lu-Prostate specific membrane antigen (¹⁷⁷Lu-PSMA) based radioligand therapy. He had a partial response after 2 cycles of ²²⁵Ac-PSMA based targeted alpha therapy, as demonstrated on the ⁶⁸Ga-PSMA PET/CT study. However, the patient had disease progression at the end of 4 cycles of ²²⁵Ac-PSMA therapy, evident by rising prostate specific antigen levels and imaging findings. The end of treatment ⁶⁸Ga-PSMA PET/CT showed additional sites of metastases in the orbit and brain apart from overall disease progression. These are rare sites of distant spread in prostate cancer and require urgent evaluation and local treatment to prevent potential complications. The importance of detection of metastatic sites in closed cavities is because of the requirement for urgent intervention to avoid compression related complications.

The Monocle Sign in FDG-PET: A Sign of Contralateral Facial Nerve Palsy

We report three cases of unilateral F-FDG uptake in the orbicularis oculi muscle in subjects with contralateral peripheral facial nerve palsy. We argue that this asymmetric uptake pattern in fact reflects lack of metabolism on the side affected by facial nerve palsy, owing to denervation. Since the unilateral periorbital uptake resembles a monocle, we chose to call this finding the monocle sign. The monocle sign should not be confused with inflammation or tumor, but should prompt a neurological assessment for facial nerve palsy and a potential underlying disease.