Progression of clinically stable lymphedema on lymphoscintigraphy.

Lymphedema is due to dysfunction in lymphatic transport, and is divided into primary and secondary subtypes. Primary lymphedema is a congenital lymphatic abnormality or dysfunction whereas secondary lymphedema is characterized by pathologic disruption or obstruction of a previously-normal lymphatic system. The stage of lymphedema is determined clinically. Lymphoscintigraphy, however, may be used to assess disease extent, for early detection of disease progression, and can be used to direct therapy. We report a case of a 56-year-old woman with clinically stable lymphedema of 5 years, yet with lymphoscintigraphy findings compatible with disease progression.

Cutaneous and subcutaneous imaging on FDG-PET: benign and malignant findings.

F-18 fluorodeoxyglucose positron emission tomography (F-18 FDG PET) has been shown to be useful in the evaluation of many tumors due to its high sensitivity and specificity. However, false-positive interpretations may occur from benign subcutaneous and cutaneous etiologies. At our institution we have encountered FDG-PET scans which demonstrated a variety of cutaneous and subcutaneous lesions including stomas, hernias, rhinophyma, dose infiltrations, physiologic muscle uptake, and tophaceous gout. Additionally, malignant cutaneous and subcutaneous malignant lesions may also demonstrate substantial F-18 FDG uptake on PET scans, including lymphoma, skin metastases, and melanoma. The purpose of this atlas article is to demonstrate and review key features of various cutaneous and subcutaneous lesions, both benign and malignant, which can result in hypermetabolism on FDG-PET or PET-CT scans.

Primary testicular lymphoma involving the spermatic cord and gonadal vein.

We report a case of a 70-year-old man with a history of prostatic adenocarcinoma and a 3-month history of right hemiscrotal swelling. The patient underwent a CT scan, scrotal ultrasound, and F-18 FDG-PET scan to evaluate for metastatic prostate cancer. The CT scan demonstrated an ill-defined soft-tissue mass extending along the right gonadal vein. Scrotal ultrasound revealed a heterogeneous right testicular mass. The F-18 FDG-PET scan demonstrated intense hypermetabolic activity along the course of the right gonadal vein extending to the right hemiscrotum. Subsequent right radical orchiectomy and pathologic examination revealed a B-cell lymphoma, infiltrating the testicular parenchyma, spermatic cord, gonadal vessels, and adjacent soft-tissues. Lymphoma or other tumors rarely infiltrate the spermatic cord, and have only very rarely been demonstrated on PET imaging.