From metastasis to diagnosis

A five-year-old boy was admitted with complaints of abdominal discomfort, restlessness and diarrhoea for two years. He was admitted to the hospital with complaints of swelling on his forehead, pain in lower back and weakness in legs. Radiologic imaging was performed before further laboratory studies were completed.

In cranial CT and MRI, in the upper lateral part of both orbits, large lytic lesions accompanied by an extradural mass containing calcifications, surrounded by radial periosteal reaction extending to the left zygomatic bone and sphenoid wings, was observed. A similar lesion was detected in the right temporal bone (Figure 1). Then, USG and CT revealed a solid lesion originating from the right adrenal gland, filling the retroperitoneum, surrounding the main vessel structures, and containing areas of necrosis pushing these vessels, kidneys and pancreas (Figure 2). Lytic metastatic lesions were observed in manibrium sterni and left femur (Figure 3). A solid metastatic mass was detected at the level of L4 and L5 vertebrae, expanding the left neural foramen and extending into the spinal canal (Figure 4).

Background

Neuroblastoma (NRB) is the most common extracranial tumor in infants and children. It represents 7% of all childhood cancers. The most common localization of the primary tumor is the abdomen (65%). Signs and symptoms of NRB: it has a wide spectrum, depending on the location of the tumour and its metastases and associated paraneoplastic syndromes [1–4].

Clinical Perspective

The site of the primary tumour is related to the presence and location of metastases [2]. Developing paraneoplastic syndromes may complicate the picture. A summary of the spectrum of clinical manifestations is given in Table 1 (Figure 5). Half of the patients present with signs and symptoms related to localized disease. Paraspinal localized tumours in the thoracic, abdominal and pelvic regions are seen in 5–15% of cases [3,4].

Imaging Perspective

The diagnosis of neuroblastic tumour is usually suspected on the basis of the patient’s age. Local extension of NRB mainly consists of perivascular involvement, infiltration of adjacent soft tissues and organs, and extension into the spinal canal. Lymph nodes are usually located close to the primary tumour, although distant lymph nodes may be observed. Sometimes, the first findings may be due to metastases. Bone metastases are characterized by radial periosteal reactions [1].

NRB on ultrasound demonstrates a heterogeneous mass with internal vascularity. Calcification and necrosis may or may not be evident. These findings can be seen with CT [1–3]. The extent of bone lesions can be assessed by the extent of abnormal 123I-mIBG uptake [5]. In a current study, it was shown that [18F]mFBG PET-CT, which can be used in staging and showing response to treatment, can identify more neuroblastoma localizations compared to [123I]mIBG scanning [6].

Most tumours occur in a single anatomic compartment. However, some tumours may extend to the adjacent compartment. The tumour enters between the retroperitoneal organs and the vertebral column. It tends to cover the veins and can cause compression. Adjacent organs are often displaced, but more aggressive tumors may directly invade the psoas muscle or kidney [1–2].

Image-defined risk factors (IDRF) are imaging features seen at the time of NRB diagnosis that confer a poorer prognosis. Cross-sectional imaging is required to identify IDRF and metastases [1–3,7,8].

Outcome

Chemotherapy was performed for the high-risk tumour, followed by surgery for the retroperitoneal mass. Metastases regressed in the patient who was followed up in the eighth month.

Take Home Messages / Teaching Point

It is important to screen for NRB in cases with unique periosteal reaction and lytic lesion in the cranium in young children.

All patient data have been completely anonymised throughout the entire manuscript and related files