MyPACS.net: Radiology Teaching Files > Case 1202805

never visited GERMINOMA
Contributed by: Children's Hospital Omaha, Radiologist, Omaha Childrens, Creighton University and UNMC, Nebraska, USA.
Patient: 15 year old male
History: 15 year old youngman presents with a very frequent urination.
Images:[small]larger

Fig. 1: Feb 8 05.T1 COR

Fig. 2: Feb 8 05.T1 COR. Post gad

Fig. 3: Feb 8 05.T1 COR. Post gad

Fig. 4: Feb 8 05.T1 Axial Post gad

Fig. 5: Feb 8 05.T1 Axial Post gad

Fig. 6: Feb 8 05.T1 Sag Post gad

Fig. 7: Feb 8 05.T1 Axial T2

Fig. 8: low power view with lymphoid aggregate

Fig. 9: lymphocytes with admixed large cells

Fig. 10: closer view of large cells

Fig. 11: Malignant germ cells

Fig. 12: PLAP stain highlights germinoma cells

Fig. 13: CD20 (b cell marker negative in large cells) and mitoses

Fig. 14: CD3 (T cell marker) highlights lymphoid aggregate

Fig. 15: CD3 T cell marker does not highlight large cells

Fig. 16: Feb 15 05. T1 Post Biopsy

Fig. 17: Feb 15 05. Post Biopsy. Cor T1 Post gad

Fig. 18: Feb 15 05. Post Biopsy. Axial T1 Post gad

Fig. 19: Feb 15 05. Post Biopsy. Axial T1 Post gad

Fig. 20: Feb 15 05. Post Biopsy. Axial T1 Post gad

Fig. 21: Feb 15 05. Post Biopsy. Axial T1 Post gad

Fig. 22: Feb 24 05 T1 post Gad. Cyst within thecal sac in sacral region. No enhancement

Fig. 23: Feb 24 05 T2 Sag. Cyst within thecal sac in sacral region. No enhancement

Fig. 24: CT chest Feb 2 05
Findings:

Thalamic, basal ganglia and suprasellar mass which extended into the 3rd and left lateral ventricle

Initial biopsy - non-diagnostic
Second biopsy - Germinoma

Diagnosis: Germinoma----thalamic, basal ganglia and suprasellar
Discussion:

Imaging Findings:
- Pineal mass that engulfs the entire pineal gland
- Suprasellar mass with diabetes insipidus
- CNS germinomas tend to hug the midline hear the 3rd ventricle (80-90%)
- Strong uniform enhancement with or without CSF seeding
- Iso to hyperintense to gray matter—high nuclear Cytoplasmic ratio
- DWI: Restricted diffusion due to high cellularity

Pathology:
- Germinomas constitute 1-2% of all central nerve system tumors
- 2-4% of pediatric central nervous system tumors
- General path features; unencapsulated solid mass, soft and friable, tan-white coloration, without or without cystic foci
- Necrosis, calcification and hemorrhage uncommon

Clinical:
- Parinaud syndrome (paralysis with upward gaze and altered convergence)
- Diabetes insipidus can present long before MR abnormalities become apparent
- CNS GCTs primarily seen in young patients

MR FINDINGS:
- T1 weighted imaging
- -- Iso-intense or hyperintense to gray matter
- -- Early stages, may only see absent posterior pituitary bright spot
- T2 weighted images
- Iso to hyperintense to gray matter (high nuclear Cytoplasmic ratio) may have cystic or necrotic foci (high T2 signal), less commonly with hypointense foci (hemorrhage)
- FLAIR: Slightly hyperintense to gray matter
- T2 GRE: Calcification and rarely also hemorrhage
- DWI: Restricted diffusion due to high cellularity
- T1 C+: Strong, homogeneous enhancement with or without CSF seeding and with or without brain invasion
- MRS: Increased Choline, decreased NAA with or without lactate

Best imaging tool is enhanced MR of brain and spine. MR evaluation should include entire spine before surgery.

DIFFERENTIAL DIAGNOSIS
Pineal region germ cell tumors (GCTs)
- -- Pineoblastoma, pineocytoma
- -- Craniopharyngioma
- -- Hypothalamic/chiasmatic astrocytoma

Craniopharyngioma:
- Cystic, solid, and CA++ components

Hypothalamic/chiasmatic astrocytoma:
- Homogeneous enhancement, rarely associated with DI

Other pineal region masses:
- Astrocytoma
- Metastasis
- Meningioma
- Retinoblastoma
- -- Tri-lateral to evaluate orbits and suprasellar regions

Other:
- PNET
- Hamartoma (Iso-intense with gray matter, non-enhancing)
- Suprasellar arachnoid cyst (CSF density/intensity; no enhancement)
- Langerhans cell histiocystosis (LCH)
- -- Infiltrating enhancing hypothalamic/infundibular lesion, positive DI
- Sarcoid
- Metastases

References:

Osborn Anne G., Blaser Susan I. et al. Pocket Radiologist-Brain Top 100 Diagnoses. Salt Lake City: W.B. Saunders Co. 2003.

Contributed by:
Phillip Silberberg MD, Omaha Children's Hospital, Creighton and UNMC, Omaha, NE
Deb Perry and Chris Reyes, Omaha Children's Hospital, Omaha, NE
Benjamin Silberberg

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Additional Details:

Case Number: 1202805Last Updated: 04-30-2005
Anatomy: Cranium and Contents   Pathology: Neoplasm
Modality: MR, PathologyExam Date: Access Level: Readable by all users
Keywords: germinoma----thalamic, basal ganglia and suprasellar

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