Final Diagnosis -- Dandy-Walker-Malformation, Teratoma and Metastatic Lung Adenocarcinoma


  1. Dandy-Walker-Malformation
  2. Mature midline posterior fossa teratoma.
  3. Metastatic lung adenocarcinoma to the right cerebellar hemisphere.


The differential diagnosis of the occipitally located tumor included meningeal metastasis of the known adenocarcinoma. However, the tumor was comprised of three germ layers with mesenchymal neuroectodermal and endodermal tissue corresponding to a mature teratoma. Teratomas within the central nervous system (CNS) are scarce tumors with a reported incidence of 0.006 per 100.000 per year and with a fraction of 82 % representing nonmalignant teratomas (9). Matsutani and colleagues showed that mature teratomas make up to 12.4 % of intracranial germ cell tumors. In their study, the age of analyzed patients was 11.6 +/- 8.5 years (mean +/- standard deviation) with nearly all cases located in the pineal region (17/19) and all patients being male (8). A recent study reported 35/43 CNS teratomas being pediatric (?16 years), while 8 cases were adults (4). The pediatric teratomas were localized in the spinal cord (23/35) and intracranially (12/35). 8/12 intracranially located cases represented mature teratomas and were localized in the third ventricle, frontobasally or occipitally (4). The latter localization was sometimes associated with an encephalocele (4). Mature CNS teratomas occurring in adults are an absolute rarity with only few reports existing in the literature. Localizations are described within the spine, the sellar region, the occipital lobe and the pineal region (12), (1), (2). Only single case reports present adult patients with mature teratomas of the posterior fossa (3, 10), underlining the sparsity of our case.

Vermis aplasia and the enlarged posterior fossa reported here are both part of the Dandy-Walker Malformation (DWM). DWM is a rare congenital disorder that was initially reported as a triad of cystic dilatation of the fourth ventricle, vermis hypoplasia and hydrocephalus (11), but can present with a variety of morphologic features and clinical symptoms (5). Typically, DWM patients display severe neurological symptoms in early childhood, and the majority of patients show associated neural malformations (5). Our patient was adult and did not report on any neurological symptoms. We did not detect any abnormalities in the forebrain. Instead, a teratoma was attached to the meninges that had a bridge-like connection to the cerebellum, suggesting that this tumor was part of the malformation. While single DWM cases have been reported with co-occuring lipomas, hamartoma, neurocutaneous melanosis or dermoid cysts (5), (7), (6), the here presented case is, to our knowledge, the first report showing a combination of DWM and a teratoma, which should be taken into consideration when observing similar phenomena on MR imaging.


  1. Agrawal M, Uppin MS, Patibandla MR, Bhattacharjee S, Panigrahi MK, Saradhi V, Rani JY, Purohit AK, Challa S (2010) Teratomas in central nervous system: a clinico-morphological study with review of literature. Neurology India.58(6):841-6.
  2. Bromberg JE, Baumert BG, de Vos F, Gijtenbeek JM, Kurt E, Westermann AM, Wesseling P (2013) Primary intracranial germ-cell tumors in adults: a practical review. J Neurooncol.113(2):175-83.
  3. Drapkin AJ, Rose WS, Pellmar MB (1987) Mature teratoma in the fourth ventricle of an adult: case report and review of the literature. Neurosurgery.21(3):404-10.
  4. Goyal N, Kakkar A, Singh PK, Sharma MC, Chandra PS, Mahapatra AK, Sharma BS (2013) Intracranial teratomas in children: a clinicopathological study. Childs Nerv Syst.29(11):2035-42.
  5. Hart MN, Malamud N, Ellis WG (1972) The Dandy-Walker syndrome. A clinicopathological study based on 28 cases. Neurology.22(8):771-80.
  6. Kang SG, Yoo DS, Cho KS, Kim DS, Chang ED, Huh PW, Kim MC (2006) Coexisting intracranial meningeal melanocytoma, dermoid tumor, and Dandy-Walker cyst in a patient with neurocutaneous melanosis. Case report. J Neurosurg.104(3):444-7.
  7. Kim YJ, Won YD, Kim KT, Chang ED, Huh PW (2006) Parenchymal neurocutaneous melanosis in association with intraventricular dermoid and Dandy-Walker variant: a case report. Korean journal of radiology : official journal of the Korean Radiological Society.7(2):145-8.
  8. Matsutani M, Sano K, Takakura K, Fujimaki T, Nakamura O, Funata N, Seto T (1997) Primary intracranial germ cell tumors: a clinical analysis of 153 histologically verified cases. J Neurosurg.86(3):446-55.
  9. McCarthy BJ, Shibui S, Kayama T, Miyaoka E, Narita Y, Murakami M, Matsuda A, Matsuda T, Sobue T, Palis BE, Dolecek TA, Kruchko C, Engelhard HH, Villano JL (2012) Primary CNS germ cell tumors in Japan and the United States: an analysis of 4 tumor registries. Neuro-oncology.14(9):1194-200.
  10. Sanyal P, Barui S, Mathur S, Basak U (2013) A case of mature cystic teratoma arising from the fourth ventricle. Case reports in pathology.2013:702424.
  11. Sutton J (1887) The lateral recesses of the fourth ventricle: their relation to certain cysts and tumors of the cerebellum and to occipital meningocele. Brain 9:352-61.
  12. Sweiss RB, Shweikeh F, Sweiss FB, Zyck S, Dalvin L, Siddiqi J (2013) Suprasellar mature cystic teratoma: an unusual location for an uncommon tumor. Case reports in neurological medicine.2013:180497.

Contributed by Julia Pöschl, Frank Berger, Hans Kretzschmar and Ulrich Schüller

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