View source for Brain metastasis

{{ Infobox diagnosis
| Name       = {{PAGENAME}}
| Image      = Metastatic_adenocarcinoma_-_cerebellum_-_high_mag.jpg 
| Width      =
| Caption    = Metastatic adenocarcinoma, compatible with colorectal primary. [[HPS stain]].
| Synonyms   =
| Micro      = usu. well-demarcated border between brain and lesion, no cytoplasmic processes (seen in glial tumours), usu. have [[nuclear atypia]] of malignancy, +/-glandular architecture, +/-nucleoli seen
| Subtypes   =
| LMDDx      = primary brain tumour - see ''[[Neuropathology_tumours#Primary_versus_secondary|primary brain tumour versus secondary brain tumour]]'' 
| Stains     =
| IHC        = GFAP -ve, dependent on primary - typical +ve for keratins (as carcinoma)
| EM         =
| Molecular  =
| IF         =
| Gross      =
| Grossing   =
| Site       = [[brain]]
| Assdx      =
| Syndromes  =
| Clinicalhx =
| Signs      =
| Symptoms   =
| Prevalence = most common brain tumour (adults)
| Bloodwork  =
| Rads       = intra-axial, typically grey-white junction, cerebellum (esp. in adults) 
| Endoscopy  =
| Prognosis  = poor
| Other      =
| ClinDDx    = primary brain tumour, cerebral abscess or infection
| Tx         = surgery, chemotherapy, radiation therapy 
}}
'''Brain metastasis''', also '''metastatic brain tumour''',<ref>URL: [http://www.nlm.nih.gov/medlineplus/ency/article/000769.htm http://www.nlm.nih.gov/medlineplus/ency/article/000769.htm]. Accessed on: November 8, 2014.</ref> is a [[brain tumour]] that arose elsewhere and spread to the brain. 

==General==
*Most common brain tumour in adults.<ref>{{Cite journal  | last1 = Pekmezci | first1 = M. | last2 = Perry | first2 = A. | title = Neuropathology of brain metastases. | journal = Surg Neurol Int | volume = 4 | issue = Suppl 4 | pages = S245-55 | month =  | year = 2013 | doi = 10.4103/2152-7806.111302 | PMID = 23717796 }}</ref><ref>{{Cite journal  | last1 = Suki | first1 = D. | last2 = Khoury Abdulla | first2 = R. | last3 = Ding | first3 = M. | last4 = Khatua | first4 = S. | last5 = Sawaya | first5 = R. | title = Brain metastases in patients diagnosed with a solid primary cancer during childhood: experience from a single referral cancer center. | journal = J Neurosurg Pediatr | volume = 14 | issue = 4 | pages = 372-85 | month = Oct | year = 2014 | doi = 10.3171/2014.7.PEDS13318 | PMID = 25127097 }}</ref>
** Brain metastases are found in up to 25% cancer patients at autopsy. <ref>{{Cite journal  | last1 = Gavrilovic | first1 = IT. | last2 = Posner | first2 = JB. | title = Brain metastases: epidemiology and pathophysiology. | journal = J Neurooncol | volume = 75 | issue = 1 | pages = 5-14 | month = Oct | year = 2005 | doi = 10.1007/s11060-004-8093-6 | PMID = 16215811 }}</ref>
**Incidence of brain metastases increases with age.
** 80% of brain metastases are located supratentorial, usu. at the border between white and grey matter.
*In more than 50% there are multiple metastases in the brain.  
*Common primary sites (in order of prevalence): [[lung cancer|lung]], [[invasive breast cancer|breast]], [[renal cell carcinoma|kidney]], [[Gastrointestinal pathology|gastrointestinal]], [[melanoma]].<ref>{{Ref TN2007|NS9}}</ref>
*Percentage of previously diagnosed cancers with brain metastases - by primary site: lung cancer 19.9%, melanoma 6.9%, breast cancer 5.1%, renal cancer 6.5%, colorectal cancer 1.8%.<ref name=pmid15254054>{{Cite journal  | last1 = Barnholtz-Sloan | first1 = JS. | last2 = Sloan | first2 = AE. | last3 = Davis | first3 = FG. | last4 = Vigneau | first4 = FD. | last5 = Lai | first5 = P. | last6 = Sawaya | first6 = RE. | title = Incidence proportions of brain metastases in patients diagnosed (1973 to 2001) in the Metropolitan Detroit Cancer Surveillance System. | journal = J Clin Oncol | volume = 22 | issue = 14 | pages = 2865-72 | month = Jul | year = 2004 | doi = 10.1200/JCO.2004.12.149 | PMID = 15254054 }}</ref>
**''Lung'' followed by ''kidney'' is the order in a smaller series.<ref>{{Cite journal  | last1 = Schouten | first1 = LJ. | last2 = Rutten | first2 = J. | last3 = Huveneers | first3 = HA. | last4 = Twijnstra | first4 = A. | title = Incidence of brain metastases in a cohort of patients with carcinoma of the breast, colon, kidney, and lung and melanoma. | journal = Cancer | volume = 94 | issue = 10 | pages = 2698-705 | month = May | year = 2002 | doi =  | PMID = 12173339 }}</ref>
*Treatment: Surgery 1-3 metastases, Stereotactic RT in 1-4(rarely up to 10) metastases, >4-10 metastases: Whole Brain RT.

==Gross/Radiology==
*Intra-axial location.
**Typically at the grey-white junction.<ref name=pmid19727563>{{Cite journal  | last1 = Della Puppa | first1 = A. | last2 = Dal Pos | first2 = S. | last3 = Zovato | first3 = S. | last4 = Orvieto | first4 = E. | last5 = Ciccarino | first5 = P. | last6 = Manara | first6 = R. | last7 = Zustovich | first7 = F. | last8 = Berti | first8 = F. | last9 = Gardiman | first9 = MP. | title = Solitary intra-ventricular brain metastasis from a breast carcinoma. | journal = J Neurooncol | volume = 97 | issue = 1 | pages = 123-6 | month = Mar | year = 2010 | doi = 10.1007/s11060-009-9988-z | PMID = 19727563 }}</ref>

Image:
*[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3656562/figure/F1/ Brain metastases (nih.gov)].<ref name=pmid23717796 >{{Cite journal  | last1 = Pekmezci | first1 = M. | last2 = Perry | first2 = A. | title = Neuropathology of brain metastases. | journal = Surg Neurol Int | volume = 4 | issue = Suppl 4 | pages = S245-55 | month =  | year = 2013 | doi = 10.4103/2152-7806.111302 | PMID = 23717796 }}</ref>

<gallery>
File:AFIP403613G-THYROID PAPILLARY CARCINOMA METASTATIC TO BRAIN.jpg | Well demarcated metastasis (WC/Dr. Kostich)
File:BrainMetastasisFromBreastCancer.jpg | 3 brain metastases in breast cancer (WC/Jmarchn)
</gallery>

==Microscopic==
Appearance varies by subtype. 

Features of [[metastatic carcinoma]]:
*Tubule formation/glands.
*Usually well-circumscribed/sharply demarcated from surrounding tissue.
*Usually nuclear atypia including:
**Nuclear hyperchromasia.
**Variation of nuclear size.
**Variation of nuclear shape.
*Mitoses - common.

DDx:
*Primary brain tumour - ''see [[Neuropathology_tumours#Primary_versus_secondary|primary brain tumour versus secondary brain tumour]]''.

===Images===
<gallery>
Image:Metastatic_adenocarcinoma_-_cerebellum_-_very_low_mag.jpg | [[CRC]] metastasis to cerebellum - very low mag. (WC)
Image:Metastatic adenocarcinoma - cerebellum - intermed mag.jpg| CRC metastasis to the cerebellum - intermed. mag. (WC)
Image:Metastatic_adenocarcinoma_-_cerebellum_-_high_mag.jpg | CRC metastasis to cerebellum - high mag. (WC)
Image:Brain metastasis - high mag.jpg | Brain metastasis - high mag. (WC)
File:Adenocarcinoma infiltrating the brain.jpg | Adenocarcinoma of the lung metastasis. (WC/jensflorian)
</gallery>

==IHC==
{{Main|Immunohistochemistry}}
*Carcinoma: pankeratin +ve.
**[[Lung adenocarcinoma]] and SCLC: TTF-1 +ve, CK7 +ve, CK20 -ve.
**Breast carcinoma: CK7 +ve, ER +ve, PR +ve, BRST2 +ve/-ve.
**Colorectal carcinoma: CK7 -ve, CK20 +ve, CDX2 +ve, TTF-1 -ve.
**[[Clear cell renal cell carcinoma]]: PAX8 +ve, CK7 -ve, CK20 -ve, vimentin +ve, CD10 +ve.
*Melanoma: S-100 +ve, HMB-45 +ve, Melan A +ve.
*GFAP -ve.<ref name=pmid23717796 >{{Cite journal  | last1 = Pekmezci | first1 = M. | last2 = Perry | first2 = A. | title = Neuropathology of brain metastases. | journal = Surg Neurol Int | volume = 4 | issue = Suppl 4 | pages = S245-55 | month =  | year = 2013 | doi = 10.4103/2152-7806.111302 | PMID = 23717796 }}</ref>

Other glial markers (suggest primary):<ref name=pmid23717796/>
*OLIG2, SOX2.

<gallery>
File:Immunhistochemie Bronchialkarzinom.jpg | CK7+/CK20-/TTF1+ profile in pulmonary adenocarcinoma metastasis. (WC/Marvin101)
</gallery>

==Origin==
===Breast===
*8-30% BM.
*Triple-negative cases have a poor prognosis.
==See also==
*[[Neuropathology tumours]].
*[[Metastasis]].

==References==
{{Reflist|2}}

[[Category:Neuropathology]]
[[Category:Diagnosis]]