A 42-year-old female had undergone surgery for a mass in her left eye causing orbital pain and paresthesia and the pathology turned out to be adenoid cystic carcinoma of lacrimal gland. Patient was lost to follow up during 10 years period and eventually a ¹⁸F-FDG PET/CT study was performed.

Widespread metastatic lesions of adenoid cystic carcinoma at both lungs.

Adenoid cystic carcinomas of the lacrimal gland are rare FDG avid malignant tumors. They are indolent tumors, which tend to spread to adjacent structures and occasionally metastasize via hematogenous spread to lungs, brain, and bone.

A 52-year-old male who was diagnosed with the basal cell adenocarcinoma of the right parotid gland underwent ¹⁸F-FDG PET/CT before and after surgical resection of the tumor.

¹⁸F-FDG PET/CT study showed the therapy response at right parotid gland tumor. The pathological uptake at the transverse process of Lomber 2 vertebra is due to simple fracture rather than being a metastasis.

A 45-year-old female was diagnosed as oncocytic carcinoma of the right parotid gland and underwent ¹⁸F-FDG PET/CT for staging.

¹⁸F-FDG PET/CT study showed intensely increased FDG uptake at right parotid gland mass confirming the malignant nature of the lesion

Oncocytic carcinoma is an extremely rare malignancy in salivary glands, accounting only for 0.5 % of all epithelial salivary gland malignancies. Oncocytic carcinoma is an FDG avid malignancy but one must bear in mind that benign pathologies of salivary glands like oncocytoma, pleomorphic adenoma, and Warthin tumor are also FDG avid.

A 34-year-old male with nasopharyngeal carcinoma was evaluated with PET/CT before and after having chemotherapy and radiotherapy.

Intensely hypermetabolic mass lesion at nasopharynx consistent with nasopharyngeal carcinoma and right cervical metastatic lymph nodes. All of the pathological activities are cleared after treatment indicating complete metabolic response to therapy.

¹⁸F-FDG PET/CT can precisely assess response to therapy in nasopharyngeal carcinoma, which gives prognostic information for patients. The SUVmax corresponds well with response of tumor to treatment, with greater decreases in SUVmax correlating well with better survival.

A 55-year-old male underwent resection of tongue for tongue carcinoma and after surgery had a flap reconstruction of the tongue. The patient was referred for restaging purpose and a ¹⁸F-FDG PET/CT study was performed.

Extensive FDG uptake at the posteromedial border of the flap compatible with recurrence of the primary malignant disease.

Recurrence of tumor may not be detectable clinically especially when the lesion is deep to the flap reconstruction. The thickening along the flap border due to postsurgical changes and granulation tissue may not be possible to be distinguished from recurrence with anatomical imaging methods. FDG PET/CT is effective in detecting the relapse of the tumor in such cases.

A 75-year-old female had the diagnosis of squamous cell carcinoma of the epiglottis after a biopsy and underwent ¹⁸F-FDG PET/CT scan for pretreatment staging.