CASE 15699 Published on 24.04.2018

Bone metastasis of primitive occult neuroblastoma

Section

Paediatric radiology

Case Type

Clinical Cases

Authors

Carmen M. Botía González1, Sara I. Sirvent Cerdá2, Daniel Azorín3

(1) Hospital Morales Meseguer,
Department of radiology;
Avenida Marques de los Velez
30008 Murcia, Spain;
Email:Carmenbotiaglez@gmail.com

(2) University Hospital Niño Jesús,
Department of Radiology,
Av. de Menéndez Pelayo, 65,
28009 Madrid, España

(3) University Hospital Niño Jesús,
Department of Pathology,
Av. de Menéndez Pelayo, 65,
28009 Madrid, España
Patient

2 years, male

Categories
Area of Interest Paediatric ; Imaging Technique Conventional radiography, MR, Percutaneous
Clinical History
A two-year-old boy complained of pain and swelling in his right arm for the past two months, with no previous history of trauma. He was in a good clinical state, and no other associated signs or symptoms were present.
Imaging Findings
An AP radiograph of the right humerus revealed an extensive permeative lesion of the medullary bone and a discontinuous periosteal reaction (Fig. 1), findings consistent with a lesion of aggressive biological behaviour (leukaemia, lymphoma, Ewing sarcoma, osteomyelitis, or metastasis of a neuroblastoma).

An MRI of the right humerus showed a bone lesion that extended from the proximal metaphysis to the distal diaphysis of the right humerus (Fig. 2a). The lesion had an associated soft tissue mass and both the bony and the soft tissue lesions were hyperintense on the STIR sequence (Fig. 2a), hypointense on T1-weighted sequences (Fig. 2b), and showed intense and heterogeneous enhancement after administration of intravenous contrast (Fig. 2c, 2d).

Therefore, a biopsy was performed, whose result was consistent with a neuroblastoma metastasis (Fig. 3). There was no N-myc amplification. The primary tumour was not found on either whole body MRI or on an MIBG scan.
Discussion
Neuroblastoma is a tumour that derives from the primordial neural crest cells that form the sympathetic nervous system. It constitutes the most common solid extra-cranial malignancy in children, with a median age at diagnosis of around 16 months, and 95% of cases being diagnosed by 7 years of age. Its main feature is its variable biological behaviour, with tumours being potentially lethal and others undergoing spontaneous regression without any treatment [1].

The main prognostic factor of this neoplasm is its presurgical stage. This is because complete resection of the tumour is key for the survival of these patients, and the more advanced the disease, the poorer the prognosis. The presence of N-myc amplification also gives a worse prognosis. In high risk patients, other treatments are considered. In our case, the patient was treated with chemotherapy and auto stem cell transplant, and has had no relapse until now (two years later).

Neuroblastoma metastases are very prevalent, with bone marrow (70%), bone (55%), and liver being the most affected sites [1]. Bone metastases most commonly present with pain and swelling. They typically occur in the long bones of the extremities [2], skull, and bony orbit, for which this tumour has an unexplained predilection to metastasise [3].

The radiological appearance of bone metastases of neuroblastoma is variable, even though it often reflects its aggressive behaviour: in the skull, it typically manifests as thickening of the bone (the so-called “hair-on-end” periosteal reaction) or lytic defects and separation of sutures [4], whereas in long bones, it tends to present as a permeative lesion with an aggressive periosteal reaction, or even as pathological fractures [3, 4].
Nevertheless, this pattern is not specific, and in children, it may be also seen in other conditions such as osteomyelitis, Ewing sarcoma, lymphoma or leukaemia [5].

On MRI, bone metastases of neuroblastoma are seen as hyperintense on STIR and show intense enhancement after the administration of intravenous contrast, and this imaging technique is an effective method for their depiction in the appropriate clinical setting [4].

The presence of neuroblastoma metastases in the absence of an identifiable primary tumour is extremely uncommon, with only seventeen cases having been reported in literature [6, 7, 8]. However, due to the prevalence of this tumour in the paediatric population, it should always be included in the differential diagnosis of an aggressive lesion in the long bone of a child.
Differential Diagnosis List
Bone metastasis of neuroblastoma.
Leukaemia
Lymphoma
Ewing sarcoma
Osteomyelitis
Langerhans cell histiocytosis
Osseous rhabdomyosarcoma
Osteosarcoma
Bone metastasis of neuroblastoma
Final Diagnosis
Bone metastasis of neuroblastoma.
Case information
URL: https://www.eurorad.org/case/15699
DOI: 10.1594/EURORAD/CASE.15699
ISSN: 1563-4086
License