Fluorine-18 Fluorodeoxyglucose PET/CT Images of Hidradenitis Suppurativa Mimicking Metastasis in a Patient With Small Cell Lung Carcinoma

Abstract

A 54-year-old male patient with metastatic small cell lung carcinoma received chemotherapy and in followup he was referred to positron emission tomography (PET)/CT scan for re-staging. In addition to the primary disease, increased Fluorine-18 fluorodeoxyglucose (F-18 FDG) uptake was detected in skin and subcutaneous fat tissue in the axillary, periscrotal, and perianal regions, which was later proven as hidradenitis suppurativa in PET/CT images.

The Role of FDG-PET in the Evaluation of Hidradenitis Suppurativa: A Systematic Review

“…Similarly, in a case report of a 54-year-old man with metastatic small-cell lung cancer and a history of HS, FDG-PET scans revealed an increased uptake in the axillary, periscrotal, and perianal regions, which were clinically confirmed to be HS. Subsequent histopathological evaluation via biopsy confirmed the HS diagnosis [33]. FDG-PET/CT accurately detected both subclinical and clinical sites of HS involvement.…”

“…Five articles featured case reports on the incidental detection of HS using FDG-PET scans while investigating malignant metastases. These case reports emphasized the capacity of FDG-PET scans to detect HS and demonstrated that detected lesions require further evaluation through biopsy to exclude occult malignancy [24,[33][34][35][36]. The last two articles comprised comprehensive reviews on the usefulness of various radiological techniques in diagnosing and managing HS.…”

“…FDG-PET is known for its high sensitivity in detecting cellular inflammation in tissues and early signs of atherosclerosis [32]. Specifically in dermatology, FDG-PET has been used to ascertain systemic and vascular inflammation in psoriasis, detecting inflammatory lesions in the skin, blood vessels, joints, and liver [33]. Tissues that are hypermetabolic and inflamed exhibit a greater uptake of FDG compared to surrounding tissues, due to increased glucose uptake and vascularity.…”

“…As chronic inflammation is commonly associated with systemic diseases, such as psoriasis, it is hypothesized that utilizing FDG-PET/CT scans may aid in identifying systemic inflammation in patients with HS [33]. In many HS patients, PET has incidentally detected clinical and subclinical lesions using FDG as the radiotracer.…”

“…In many HS patients, PET has incidentally detected clinical and subclinical lesions using FDG as the radiotracer. Although imaging methods have tremendous potential in HS diagnosis and management, few publications regarding radiology and nuclear medicine in this condition exist [33]. This review aims to summarize the utility of nuclear imaging techniques with emphasis on PET in the diagnosis and treatment follow-up of HS.…”