J Neurol (2005) 252 : 1133–1134 DOI 10.1007/s00415-005-0822-z Deirdre O’Mahony Albiruni Ryan Abdul Razak Francesca Brett Liam Grogan Primary Central Nervous System Lymphoma (PCNSL) occurring in pregnancy Received: 11 October 2004 Received in revised form: 13 December 2004 Accepted: 16 December 2004 Published online: 11 July 2005 Sirs: A 34 year old female, at 28 weeks gestation, presented with a 7-day history of nausea, vomiting, headaches and left upper limb weakness. Examination revealed significant left hemiparesis involv- ing predominantly the left upper limb. Ocular examinations were normal. T-2 FLAIR sequenced MRI identified homogeneous hyperin- tense lesions in the right frontal lobe, right medial temporal lobe, basal ganglia and thalamus (Fig. 1). Cerebrospinal fluid assessment including cytology was normal. A clinical diagnosis of post-infec- tious encephalitis was made. She responded to a combination of intravenous steroids and acyclovir over a period of 2 weeks and was subsequently discharged with tapering steroid dose. She was readmitted 2 weeks later with worsening symptoms. Repeat brain MRI showed the same findings as at initial presentation. As the symptoms recurred with a reducing steroid dose, a possible diagnosis of a lymphoproliferative malignancy was suggested. She then underwent biopsy, from which the specimen showed significant infiltrate of cells with large nuclei in the leptomeningeal and perivascular parenchyma. Im- munohistochemistry were positive for CLA and CD20, consistent with high grade B-cell Non-Hodgkins Lymphoma. Systemic involvements were outruled by normal body CT findings and bone marrow exami- nation. Human immunodeficiency virus serology was negative. A diagnosis of Primary Central Nervous System Lymphoma (PCNSL) was made. The patient underwent emer- gency caesarean section at 31 weeks to a full Apgar score baby girl. A week after delivery, she underwent combination chemo- radiotherapy based on the De Angelis regimen, Memorial Sloan Kettering [3]. On completion of chemo-radiotherapy, complete response was documented and she was back in full employment. Fifteen months after treatment, she developed mild impairment of memory, ataxia and depression. Repeat MRI and lumbar puncture showed no evidence of disease recurrence or neurotoxicity. A clin- ical diagnosis of delayed neurotoxi- city associated with combined treatment was made. Otherwise the patient remains well 48 months since diagnosis. Discussion Primary Central Nervous System Lymphoma (PCNSL) is an aggres- sive lymphoma that is confined to the cranio-spinal axis. It is a rare tumour, constituting up to 3–4% of all extra-nodal Non-Hodgkins Lymphoma [1, 2, 4]. Its incidence in pregnancy has not been previously described. In PCNSL patients, cortico- steroids should be withheld prior to establishment of tissue diagnosis unless the patient has evidence of intracranial hypertension [4]. This is because corticosteroids have significant cytotoxic activity against PCNSL, making histological diagnosis impossible [5]. In addi- tion, other diseases such as multi- ple sclerosis, encephalitis and neu- rosarcoidosis may also respond to steroids [6]. This case demonstrates a num- ber of issues in managing PCNSL in the pregnant patient. For some patients, treatment delay may not adversely affect the maternal prog- nosis [7, 8]. However, for patients with significant neurological deficits, it would be imperative to deliver the child early to facilitate initiation of lymphoma therapy. This consists of a combination of chemotherapy agents, particularly methotrexate (MTX) which has significant cytotoxic activity against trophoblastic tissue [10]. The best treatment options for PCNSL have not yet been defined owing to a lack of randomised tri- als. Improved disease control and survival have been demonstrated in patients using multiagent ther- apy and dose intensity MTX with cranial RT [3, 9, 11]. Delayed neurological toxicity resulting from combined chemo- radiotherapy is a recognised com- plication particularly in the older population. It occurs in less than 30 % in younger patients [12]. The LETTER TO THE EDITORS JON 1822 Fig. 1 Axial T-2 FLAIR sequenced MRI view showing hyperintense lesions in right frontal, medial temporal lobes, basal ganglia and thalamus