LETTER TO THE EDITOR – CLINCAL CASE NOTES

Paratesticular metastases from a medulloblastoma

Rakesh KAPOOR,1 Sunil CHOUDHARY,1 Rajinder KUMAR,1 Vijay MAHESH,2

S RADHIKA,2 SC SHARMA1 and Bishan D RADOTRA2

Departments of 1Radiotherapy and Oncology, 2Pathology, Postgraduate Institute of Medical Education and Research,Chandigarh, India

INTRODUCTION

Extra-central nervous system metastases are relativelyunknown failure patterns in medulloblastoma with inci-dence ranging anywhere from 2% to 28% as reported indifferent series. The most common site of disseminationis bone and bone marrow, particularly in pelvic bone,femur, vertebra and ribs. Other localizations are alsoobserved with a lower frequency (cervical lymph node,lung, pleura, liver).

CASE SUMMARY

A male child, aged 3 years, was referred to PostgraduateInstitute of Medical Education and Research(PGIMER), Chandigarh, India on 29 March 2006 withprogressive history of headache and projectile vomitingof three months duration. The patient when first seenhad a normal Glasgow coma score (E4 M6 V5). Therewas no focal/gross neurological deficit and no signs ofmeningeal irritation. Haemogram, liver function test,kidney function test, chest X-ray, abdomen ultrasonog-raphy were normal. Contrast-enhanced computedtomography (CECT) head done on 30 March 2006showed a midline posterior fossa mass with hydroceph-alus. The cerebrospinal fluid (CSF) was negative formalignant cells. Elective right sided VP shunt was doneon 4 April 2006. Magnetic resonance imaging (MRI)head done on 6 April 2006 showed a 5 ¥ 4 ¥ 4 cm masslesion in the midline posterior fossa in relation to the 4thventricle and a well decompressed ventricular systemwith VP shunt in situ (Fig 1a,b). Midline suboccipital

craniotomy and near total excision of posterior fossamidline tumor was done on 12 April 2006. Frozensection done per-operatively was reported as medullo-blastoma. Immunostain for synaptophysin was diffuselypositive and GFAP was focally positive (Fig. 2). Post-operatively he was treated on 6.0 mol/LV Linear Accel-erator with craniospinal radiation to a dose of 36Gy/20fractions/4 weeks to the spine and 36Gy/20 fractions/4 weeks to the whole brain (German Helmet) followedby posterior fossa boost to a dose of 18Gy/10 fractions/2 weeks from 16 May 2006 to 11July 2006.

The patient was on regular follow up when on 29September 2006 he came with severe pain in the leftthigh. On clinical examination he was found to have aright paratesicular mass (Fig. 3) and matted cervicallymph nodes (level III-V) on the right side. There was nobone tenderness. X-ray of pelvis and both the femursshowed a normal study. Fine needle aspiration cytology(FNAC) from the paratesticular mass (Fig 4) and cervi-cal lymph node showed a metastatic medulloblastoma.MRI of the head and spine showed recurrent/residualdisease in the posterior fossa with CSF metastases. Abone scan showed a normal tracer uptake throughoutthe body.

DISCUSSION

Extra-CNS metastases are rare in brain tumors;however, medulloblastoma is the most common braintumor to spread outside the CNS axis.1,2 The pathogen-esis of extra-CNS medulloblastoma metastases is notcompletely elucidated. Two types of malignant cell dis-semination are proposed:3

• hematogenous dissemination can be promoted bysurgery, the malignant cells may invade peri-tumorveins during tumor resection;

• dissemination via connections between CSF and lym-phatic system.

Correspondence: Dr R Kapoor, Department of Radiotherapyand Oncology, Postgraduate Institute of Medical Educationand Research, Chandigarh-160012, India.Email: drkapoor.r@gmail.com

Accepted for publication 20 December 2007.

Asia–Pacific Journal of Clinical Oncology 2008; 4: 68–70 doi:10.1111/j.1743-7563.2008.00143.x

© 2008 The AuthorsJournal Compilation © Blackwell Publishing Asia Pty Ltd

The most common site of dissemination is bone andbone marrow. Metastases to lymph node, lung, andpleura, liver have been reported in different series. Cer-vical lymph node metastasis as was the case in this

patient could be due to dissemination via connectionsbetween CSF and lymphatic system. The exact route forparatesticular metastasis, which this patient had, is dif-ficult to point out. Medulloblastoma is known for itscervical lymph node metastases paratesticular dissemi-nation has not been known.

Clinically the child had a standard risk of recurrencethough the residual disease after surgery was notassessed by immediate postoperative MRI. It is reallydifficult to explain why the disease in this child behavedso aggressively. In a review of 160 cases of medulloblas-toma with systemic metastases (30 of them havingundergone systemic shunts) shunts had probably pro-vided the route of systemic spread in no more than 11cases.4 In several series it has been reported that hydro-cephalus has been associated with the poorest survival.4

The child had a hydrocephalus for which VP shunt wasdone both of which probably had an effect on pattern ofspread and survival outcome.

In spite of the fact that the disease is often limited tothe posterior fossa and positive CSF and metastasesoutside the CNS are rare in children5 this patient had adisseminated disease. In the pediatric population 75%of recurrences occur within the first 2 years of treat-ment6 which holds true for this patient as well as hesuffered from relapse within 5 months of surgery.

The CCG and the SIOP7,8 studies demonstrated theefficacy of adjuvant postirradiation chemotherapy inchildren with high stage disease. The patient in this casewas not given chemotherapy as he had a standard risk ofrecurrence.

Evidences are emerging to indicate that particulargenetic profiles like MYC or MYCN amplification and

(a)

(b)

Figure 1(a,b) Magnetic resonance imaging (MRI) of the headshowed a 5 ¥ 4 ¥ 4 cm mass lesion in the midline posteriorfossa in relation to the 4th ventricle and a well decompressedventricular system with VP shunt in situ.

Figure 2 Immunostain for synaptophysin was diffusely posi-tive and GFAP was focally positive.

Metastases from a medulloblastoma 69

© 2008 The AuthorsJournal Compilation © Blackwell Publishing Asia Pty Ltd

Asia–Pac J Clin Oncol 2008; 4: 68–70

loss of 17p are associated with metastatic disease atpresentation.9,10 This case report suggests that the man-agement decision should not be completely based onclinical data but the molecular prognostic factors shouldalso be incorporated into treatment making decision.Paratesticular mass in children with medulloblastomashould alert pediatricians and oncologists. We suggestthat metastases from medulloblastoma be included inthe differential diagnosis when a patient who has pre-viously undergone craniotomy for medulloblastomadevelops evident paratesticular mass.

REFERENCES

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4 Jamjoon ZA, Jamjoon AB, Sulaiman AH et al. Systemicmetastasis of medulloblastoma trough ventriculoperitonealshunt: report of a case and critical analysis of the literature.Surg Neurol 1993; 40: 403–10.

5 Haie-Meder C, Song YP. Medulloblastoma: differences inadults and children. Int J Radiat Oncol Biol Phys 1995; 32:1235–57.

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7 Zeltzer PM, Boyett JM, Finlay JL et al. Metastasis stage,adjuvant treatment and residual tumour are prognosticfactors for medulloblastoma in children: conclusion fromthe children’s cancer group 921 randomised phase IIIstudy. J Clin Oncol 1999; 17: 832–45.

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9 Scheurlen WG, Schwabe GC, Joos S et al. Molecular analy-sis of childhood primitive neuroectodermal tumoursdefines markers associated with poor clinical outcome.J Clin Oncol 1998; 16: 2478–85.

10 Eberhart CG, Cohen KJ, Tihan T, Goldthwaite PT, BurgerPC. Medulloblastomas with systemic metastases: evalua-tion of tumour histopathology and clinical behaviour in 23patients. J Pediatr Hematol Oncol 2003; 5: 198–203.

Figure 3 Right paratesicular mass.

Figure 4 Fine needle aspiration cytology (FNAC) from theparatesticular mass cervical lymph node showing a metastaticmedulloblastoma.

70 R Kapoor et al.

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Asia–Pac J Clin Oncol 2008; 4: 68–70