A Case of Gingival Metastasis from Rectal Cancer in Which Immunohistochemistry and PET-CT Were Useful for the Diagnostic Procedure

Abstract

A 50-year-old man was referred to our hospital because of a 2-month history of painful gingival swelling. Histopathological examination of the biopsy specimen showed a metastatic adenocarcinoma, and a chest-abdominopelvic CT showed multiple metastases in the lung, liver, and spleen, but failed to demonstrate the primary tumor. He had never complained of abdominal symptoms, and physical examination did not show any abnormality in the abdomen. However, immunohistochemical staining including caudal-related homeobox transcription factor (CDX-2) of the gingival tumor and PET-CT findings strongly suggested colorectal cancer as the origin. Colonoscopy then revealed a tumor in the rectum, and systemic chemotherapy was started immediately.

Nodular pulmonary amyloidosis diagnosed by ultrasound-guided percutaneous needle biopsy

“…Amyloidosis exhibits a global incidence of approximately 10 cases per million patients yearly [ 5 ]. Histologically, amyloid deposits manifest as eosinophilic amorphous deposits, identifiable through Congo red staining and typically distinctive apple-green birefringence under polarized light [ 3 , 6 ]. The common forms of amyloidosis include systemic AL amyloidosis (formerly primary amyloidosis), systemic AA amyloidosis (formerly secondary amyloidosis), systemic wild-type ATTR amyloidosis (formerly age-related or senile systemic amyloidosis), systemic hereditary ATTR amyloidosis (formerly familial amyloid polyneuropathy), and localized AL amyloidosis [ [6] , [7] , [8] ].…”

“…Therefore, the diagnosis of pulmonary amyloidosis is mainly confirmed by transbronchial lung biopsy, surgical lung biopsy, and autopsy, but there are few reports of diagnosis by ultrasound (US)-guided percutaneous needle biopsy. In addition, 18F-fluoro-2-deoxy- d -glucose positron emission tomography (18F-FDG PET) is mainly used for the diagnosis and staging of malignant tumors, although there are a few reports of 18F-FDG accumulation in lesions in amyloidosis as well [ [2] , [3] , [4] ]. Here we present a rare case of nodular pulmonary amyloidosis with high accumulation of 18F-FDG, histologically confirmed by US-guided percutaneous needle biopsy.…”

18F-FDG PET/CT in Patients with Nodular Pulmonary Amyloidosis: Case Report and Literature Review

“…PET/CT with 18 F-FDG is used to identify focal areas of increased cellular metabolism [ 3 , 4 , 5 ]. 18 F-FDG is an excellent tracer for identifying malignant lesions because of the high glucose metabolism observed in cancer cells.…”

“…As with all diagnostic modalities, 18 F-FDG PET gives false-positive [ 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 ] and false-negative [ 28 , 29 , 30 ] results. A number of metabolically active nonmalignant diseases, such as histoplasmosis, sarcoidosis, tuberculosis and aspergillosis, can result in increased 18 F-FDG accumulation [ 3 , 4 ]. On the other hand, tumors with low glycolytic activity such as carcinoids, localized bronchoalveolar carcinomas and small-sized tumors have revealed false-negative findings on a PET scan [ 28 , 29 , 30 ].…”

“…Positron-emission tomography/computed tomography (PET/CT) with 18 F-fluorodeoxyglucose (FDG) is used to evaluate patients with possible cancers [ 3 ]. In the case of pulmonary nodules, 18 F-FDG PET has been demonstrated to have a high sensitivity and specificity for malignancy [ 4 , 5 ]. In the present study, we report an unusual case of multiple pulmonary amyloid nodules in a patient with different 18 F-FDG uptakes on PET/CT.…”