Pituitary metastasis

Case contributed by RMH Neuropathology

Presentation

Patient slightly confused. Blood test showing hypopituitarism.

Patient Data

Age: 64
Gender: Female
CT

There is a heterogeneous density mass within the pituitary fossa and extending intothe suprasellar cistern and appears continuous with the hypothalamus. The dominantinferior component measures approximately 13 x 12 x 12 mm in maximum dimensions withhomogeneous enhancement superiorly and an irregular non-enhancing componentsinferiorly. It most likely represents a solid and cystic mass lesion, however, theenhancement is quite bright and a partially thrombosed aneurysm is an alternativeconsideration.

Otherwise, the ventricles and subarachnoid spaces are normal in size andconfiguration. No other focal parenchymal lesions. No midline shift or mass effect tosuggest a space-occupying lesion. No acute intra or extra-axial haemorrhage.

The paranasal sinuses, mastoid air cells and middle ear clefts are well-aerated.

CONCLUSION: Heterogeneously enhancing sellar and suprasellar mass. It most likely represent alesion with solid and cystic components, however, a partially thrombosed aneurysm is an alternative consideration.

Further assessment with an MRI/MRA is suggested, if not contraindicated.

MRI

The sella is enlarged, and its floor of the fossa is downsloping to the left side. There is a mass in the sella extending into the suprasellar cistern. This measures 1.2 x 2.0 x 1.9 cm (AP x transverse x caudocranial dimensions).

It is isointense to brain parenchyma on T1 weighted sequences and heterogeneous but predominantly hyperintense to brain parenchyma on T2.

It enhances heterogeneously, containing a hypo-enhancing, necrotic focus inferiorly on the left side of the lesion.

In the suprasellar cistern the mass abuts, superiorly displaces, and compresses the optic chiasm.

There is no evidence of extension into the cavernous sinus on either side.

The pituitary stalk is not seen, presumably contained within the mass.

No normal pituitary gland is seen separate to the mass.

No other abnormality of the brain parenchyma demonstrated on the limited sequences provided. No abnormal diffusion restriction is demonstrated.

Conclusion: Sellar mass extending into the suprasellar cistern has imaging characteristics in keeping with pituitary macroadenoma. This causes superior displacement and compression on the optic chiasm. No extension into the cavernous sinus is demonstrated.

 

Pathology

MICROSCOPIC DESCRIPTION: The sections show features of metastatic poorly differentiated adenocarcinoma. The tumour forms solid nests with areas of necrosis. No glandular structures are noted. The background stroma is inflamed and fibrous. The tumour cells have enlarged nuclei, prominent nucleoli and moderate amounts of pale eosinophilic and vacuolated cytoplasm. Foci of lymphovascular invasion are seen. No normal anterior pituitary gland tissue is present. The tumour cells are strongly CK7 and TTF-1 positive. There is weak 1+ staining for ER in 50% of the cells (interpreted as likely aberrant). They are GCDFP-15, PR, HER2, CK20, CDX-2 and WT1 negative. The immunoprofile is consistent with lung primary.

DIAGNOSIS: Pituitary tumour: Metastatic poorly differentiated adenocarcinoma, consistent with lung primary. 

CT

CT abdomen

Chest CT: enlarged right hilar lymph node measures 13 x 16 mm. There is a 4 mm spiculated nodule in the lateral right upper lobe.

Abdominal CT: bilateral adrenal masses with evidence of central necrosis involve the medial limb of the right adrenal gland and both limbs of the left adrenal gland.

IMPRESSION: The right hilar lymphadenopathy and the bilateral adrenal masses are suspicious for metastatic disease in this context. The 4 mm right upper lobe spiculated nodule is concerning for either a primary lesion or pulmonary metastasis. 

Case Discussion

Pituitary metastases are rare, and unless systemic metastatic disease is already apparent, are often preoperatively misdiagnosed as pituitary adenomas, as it happened in this case. 

 

 

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Case information

rID: 34955
Case created: 16th Mar 2015
Last edited: 13th Apr 2016
Inclusion in quiz mode: Included

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