The postradiation neck: evaluating response to treatment and recognizing complications.

OBJECTIVE: We summarize the rationale for and physiology of radiation therapy for the treatment of head and neck cancer and review the imaging findings of expected changes and complications after radiation to the neck. It is important to be able to recognize these features at all stages during management of patients with squamous cell carcinoma and other head and neck malignancies and to be able to distinguish these changes from residual or recurrent disease. CONCLUSION: Radiation therapy results in imaging findings of tissue edema followed by fibrosis, scarring, and atrophy. Complications from radiation therapy can occur months to years after treatment. Findings of a new mass, lymphadenopathy, or bone or cartilage destruction must be viewed as concerning for recurrent disease.

MR imaging of the thoracic inlet.

The thoracic inlet serves as the junction between the neck and the chest. As such, it is sometimes considered a sort of "no-man's-land" between the well-defined and comfortable territories of the thoracic radiologist and that of the head and neck radiologist. Crucial digestive, respiratory, vascular, lymphatic, and neural structures traverse the thoracic inlet. Endocrine structures also are in close proximity to, and sometimes extend into, the thoracic inlet. Familiarity with the normal anatomy of the thoracic inlet on routine chest or neck imaging, and on dedicated high-resolution examinations of such areas as the brachial plexus, is critical for detection and characterization of pathologic conditions.

An unusual cause of acute headache: subarachnoid free air secondary to spontaneous bronchopleurodurosubarachnoid fistula from a Pancoast tumor.

Pneumocephalus and pneumorrhachis are related to transgression of the barriers to the central nervous system. We present a patient with a Pancoast tumor treated with palliative chemoradiation who developed symptomatic spinal and intracranial air caused by spontaneous bronchopleurodurosubarachnoid fistula secondary to direct tumor invasion into the thecal sac.

Pediatric extraskeletal osteosarcoma.

Extraskeletal osteosarcoma (ESOS) is a rare malignant tumor composed of mesenchymal cells comprising approximately 1% of soft-tissue sarcomas and 4% of all osteosarcomas. Primary osseous osteosarcomas more commonly develop in children and adolescents, but there are very few reports of ESOS occurring in those younger than 40 years. These variants of high-grade osteosarcoma are often characterized histopathologically by the production of an osteoid matrix and bone from malignant osteoblasts that by definition are present in the soft tissue outside the normal skeletal anatomy. We present a 13-year-old girl with a gradually enlarging, painless left thigh mass.