A spontaneously vanishing primary cerebral lymphoma "ghost tumour"

Use of fluorescein sodium to obtain histological diagnosis of primary Central nervous system lymphoma ghost tumour despite disappearance on intraoperative magnetic resonance imaging: technical note and review of the literature

BACKGROUND AND IMPORTANCE

Corticosteroid pre-treatment in patients with primary central nervous system lymphoma (PCNSL) can lead to the phenomenon of ghost tumours (GhT). This affects the diagnostic yield of biopsies and potentially causes misdiagnosis of the condition. The usual strategy of neuronavigation using preoperative magnetic resonance imaging (MRI) or localisation using intraoperative MRI (iMRI) can be rendered ineffective in this situation.

CLINICAL PRESENTATION

A middle-aged Chinese male with newly diagnosed human immunodeficiency virus infection was found to have an intracranial lesion suggestive of PCNSL. Preoperatively corticosteroid led to an attenuation of the contrast enhancing lesion on iMRI. However, intraoperative use of FS allowed the successful identification, biopsy and diagnosis of the condition.

CONCLUSION

FS is useful in the biopsy of PCNSL GhT even when the lesion is not seen in subsequent MRI imaging.

Diagnostic radiation-induced regression of a metastatic primary intracranial germinoma: a case report

Pineal region germinomas are sensitive to radiotherapy. Standard neurosurgical management involves obtaining a tissue biopsy and to relieve the often accompanying obstructive hydrocephalus. We present a patient with a suspected hyper-radiosensitive metastatic primary intracranial germinoma where computed tomography scanning resulted in tumor regression before radiotherapy could be administered.

Spontaneous regression of congenital brain tumors: a report of two cases

BACKGROUND

Vanishing brain tumor is defined as spontaneously disappearing or decreasing of the initial brain mass volume to ≤ 70% before establishing the definitive diagnosis. The condition is rare and can be attributed to different factors. The exact mechanism is under debate, but the increasing rate and accuracy of neuroimaging studies and occurrence of similar scenario in other pathologies rather than brain tumors can be of particular importance in finding vanishing brain lesions.

CASE REPORT

We present two unusual cases of congenital brain masses which underwent spontaneous shrinkage within the first months of life.

CONCLUSION

The condition is scarcely observed in congenital brain masses. As congenital brain lesions are distinct entities with peculiar characteristics, this rare phenomenon may reflect different aspects in this age group.

Primary central nervous system lymphoma with preceding spontaneous pseudotumoral demyelination in an immunocompetent adult patient: A case report and literature review

The rapid disappearance of primary central nervous system lymphomas (PCNSL) following steroid therapy is common; however, the spontaneous regression of PCNSL without any treatment is extremely rare. This study presented a rare case of PCNSL with preceding pseudotumoral demyelination and no previous steroid treatment, and the pitfalls of PCNSL diagnosis were discussed. A 70-year-old healthy male experienced memory and gait disturbances and showed multiple enhanced lesions with perifocal brain edema in the left cerebrum. The patient had no previous symptoms, no chronic lesions and negative oligoclonal immunoglobulin G bands in the cerebrospinal fluid. Histological examination of a brain biopsy specimen revealed predominantly destructive, demyelinating characteristics with infiltration of several T lymphocytes and foamy macrophages resulting in the diagnosis of multiple sclerosis. The patient received steroid therapy and demonstrated gradual improvement, multiple brain lesions had disappeared from the magnetic resonance imaging (MRI)scan two months after the biopsy. However, three months after the biopsy, the condition of the patient deteriorated. MRI indicated a homogeneous enhanced lesion in the right frontal lobe and a second biopsy was performed. Histological examination during the second biopsy revealed a diffuse large B-cell lymphoma. The patient received whole-brain radiation and steroid therapy, however, succumbed eight months following the initial diagnosis. In the current report a comparison between the our case and six previously reported cases is presented.

Long-term follow-up of vanishing tumors in the brain: how should a lesion mimicking primary CNS lymphoma be managed?

OBJECTIVES

The spontaneous disappearance of a tumor is referred to as a vanishing tumor. Most vanishing tumors in the brain are eventually diagnosed as malignant tumors or multiple sclerosis. However, their long-term clinical course remains unclear. This study aims to elucidate the management of vanishing tumors in the brain.

PATIENTS AND METHODS

We defined a vanishing tumor as a case in which the tumor spontaneously disappeared or decreased to less than 70% of the initial tumor volume before definitive diagnosis and treatment (other than steroid treatment). Ten cases of vanishing tumors are reviewed.

RESULTS

Nine patients underwent biopsy at least once. Five patients, all of whom had malignant tumors (primary central nervous system lymphoma: 4, germinoma: 1) that recurred in 4-45 months (median: 7 months), underwent a second biopsy after the reappearance of the tumors. Five patients (tumefactive demyelinating lesion: 1, undiagnosed: 4) who had no relapse are alive, and their median follow-up time is 44 months. No cases have yet been reported of malignant brain tumors that recurred more than 5 years after spontaneous regression.

CONCLUSIONS

Patients with vanishing tumors should be followed up carefully by magnetic resonance imaging for at least 5 years, even after the disappearance of an enhancing lesion.