Lipoblastic Meningioma: ‘Vacuolated Meningioma” RAFFAELE LAllES, MD, AND GIULIO BIGOTI-I, MD This report describes and illustrates seven cases of benign meningeal tumors, including one in the retro-bulbar region of the orbit, which were characterized by vacuolated signet-ring cells. Occasional typical meningothelial areas were also seen; however, the signet-ring cells were the dominant feature. The vacuoles were consistently negative with the various stains for mucin. In one single case in which nonparaffin-embedded tissue was still available, the vacuoles were positive for fat stains. Immunohistochemical stains done in three of the cases showed that the tumor cells were positive for vimentin. S-100 protein was definitely positive in two cases and weakly positive in one. One of the three cases was positive for cytokeratin and another was positive for epithelial membrane antigen. The name “lipoblastic meningioma” appears to be acceptable as a descriptive term, since these tumors are, in our opinion, of definite meningeal origin, probably representing a predominantly mesenchymal (lipocytic) differentiation of the arachnoidal cells. This term, however, does not imply a clinical behavior analogous to that of true liposarcoma. In fact, these tumors have consistently behaved as benign local problems, analogous to the biologic course of ordinary meningioma. HUM PATHOL 22:164-171. Copyright ;i” 1991 by W.B. Saunders Company
Beside the classic nienin~othelial meningioma and the well-known variants, amon,g. which :11-t‘ the so-called fibroblastic, syncytial, transltlonal, :111dangiarid the less f‘requent but wellomatoid types, documented occurrence in meningioma of‘ heterologous elements, such as osteoid and cartilage.‘-3 there IS a much more un~~sual morphologic type of’ meningioma referred to in the literature as lipoblastic. vacuolated.‘.” or microcystic nieningioma.7X ‘IIe biologic behavior of’this variant is comparable to that of ordinary meningiomas. but its recognition bj, the pathologist is of‘ paramount importance because of’ the ease with which it call be mistaken f‘or liposarcoma, metastatic mutinous carcinoma, 01‘ even chordoma.” In this report, the clinicopathologic, histochemical, and immunohistochemical fatures of’ seven cases. collected at Columbia University College of Physicians and Surgeons (New York, NY), including one exceptional case of extracranial lipoblastic meningioma presenting as an intraorbital tumor, are reviewed. From the Department of Pathology. Di\ ision of Surgical Pathology. Columbia L!niversity (;ollegr of Physicians and Surgeons. 630 West 168th St. New ~‘oI-k. NY. Accepted fat- publication hIa) 15. IYYO. K interpreted as metast& signet-ring cell carcinoma. but. since no primarv tumor was found elsewhere. an exenteration of the left’ orbital contents was performed. The patient was subsequently fi)llowed fi)r I8 years. during which there were no signs of’ local recurrence or metastasis. No other primal-v tumor was discovered. On gross esamination, the turn& appeared as a well-circumscribed, apparently encapsulated. smooth-surtacecl. oval. sof‘t tan-colored mass. 3.5 X 2.j X 2.5 cm, located in the medial part of the orbit, apparentlv not adherent to the globe. The optic nerve was not grossly ‘in\A,ed by tumor. Microscopically, the tumor was a highly cellular tissue composed of’ vacuolated cells with a definite signet-ring appearance, arranged compactly in multiple lobules separated hy fibrovascular traheculae and muscle fihers (Figs I and 2). ‘I‘he nuclei were generally vesicular. hut occasionally hkarre and hyi)erchromatic. Some possible microscopic extensions ot the tumor into the surrounding tissues were seen (Fig 1). Mucicar164
LIPOBLASTIC MENINGIOMA (L&es
FIGURE 1. (Case no. 1) Photomicrograph of the tumor at its periphery, showing that It is made k~p predominantly of signet-ring cells. The capsule of the tumor cons& of compressed orbital tissue where some striated muscle fibers are entrapped in the reactive fibrous tissue. (Hematoxylin-eosin stain; magnificatiorl 1 100.)
drsc t-itwl.
Oil
norl\~rl).
;I tiliilor
in ttlt
FIGURE 2. (Case no. 1) The histologic features of the tumor at a higher power. Note that the signet-ring cells are fairly uniform In size, and that the nuclei are hyperchromatic but show no mitotic activity or bizarre shapes. (Hematoxylin-eosin stain; magnification * 300.)
165
& Blgottl)
HUMAN PATHOLOGY
Volume 22, No. 2 [February 1991)
FIGURE 3. [Case no. 1) Reticulin stains. Note the practically complete absence of reticulin fibrils between tumor cells, resulting in an epithelial-like pattern. (Wilder stain; magnification x 100.)
present (Fis 4). Mucirt and PAS stains were nrgativc. ‘1 richrotne starts showed scant\ collagett, especi;tlly atwttid blood vessels. Relic ulin stains outlined the rich v,tscularit\ and fine fihrils surtmuriclirig Iurnot- c.ell nests. Fat stairts 011 frozen sections revealed clef’irtite positivity of’ sortte but not all neoplastic elements. Neoplastic c-ells wtlh tnultiple small cytoplasrnic \acuoles were rtiore obviowly stained 1hart those with large. single vacuoles. rnatt who Cnsr 110. 3. The patient W;IS ;I 44vear-oltl began to complain of visual irnp;iirrttet;r 1 weel\ prior lo admission. On phyktl exatttirtatiott. positiw findings itteluded a blood pt~ss~rw of’ 150 over 100. 011 f’uttdust epic examination, bilateral papilledettta was ptwettr. with hrnorrhages on the left. A txaitt scan wis done, arid showetl ittcreased uptake of‘ radioactive isotope over the right t’rott-
tat ;it-ea. 11 righr catmtitl at~~t7iogr;tni was also perfortttrd, xnd twealecl 2 large, sharply citxxtrnscribed tumor ttiass in the right f’rotital at331 which stained ttotnogetteo~tsf~ with the dve. Surgrty bv;ts perfi)rrtied. arid, through ;I righ’ tl-orit;tl ctxtio~ottty, ;I I;irge I LIII~OI~ rttass attached ariterior.1~ to the fils was excised. (:otttr.ol of’ bleeding was initially trow t&3ottte. xitl there was xi estimated total blood loss of 3,000 ~111i. The pa&tit was alive and well H years aftet exe-ision. (~txxislv. Ihe tutnot‘ consisted of’ a large. 5.0 X 1.5 (tn. ni;iss weighing 3X g, globular iti shape, kidi otie flartetred side shtrwittg 5crarids of. brownish rissue on its surf’ace. ‘I‘he retttainder of‘ the surface w;ix fkirly smooth and soft. hlic-t~oscof~i~all~. the ttttttot‘ showed tttoderately wllulat tissur with ;I prortt~nettt \,asc-rtlarirv. The tumor tissue coiv
FIGURE 4. [Case no. 2) Note the association of typical meningothelial areas and lipoblastic areas with vacuolated signetring cells. There is considerable vascularity (Hematoxylin-eosin stain; magnification x 100.1
LIPOBIASTIC MENINGIOMA (Lattes & Bigotil)
FIGURE 5. (Case no. 3) Lipoblastic pattern. In this case, the vacuolated cells vary considerably in size and shape. There is, however, no anaplasia of the nuclei or detectabk? mltotic activity Some of the cells are multivacuolated. (Hematoxylineosin stain; magnification x 300.)
FIGURE 6. [Case no. 3) Another field showing a striking angiomatoid, almost hemangiopericytomatous, pattern. Vacuelated ceils are present but they are small and inconspicuous, (Hematoxylin-eosin stain; magnification \ 300.)
167
HUMAN PATHOLOGY
Volume 22, No. 2 (February 1991)
FIGURE 7. (Case no. 4) The lipoblostic component IS admixed with typical menrngothelial foci. (Hematoxylin-eosin stain; magnification n 100.) (Inset] A group of lipoblastrc cells whtch vary in size and shape, and are often multivacuolated. (Hematoxyin-eosin stain, magnificatron k 300.)
tli;tnietc~t~, sistul
01
n.15
t~Lrl~lx~t~\ ;ifttI
\;I( Liol,ttc.~l
trlls
xix\
bvitlt
Rlic t-oscopic~~ill~,
irrtitot~tit
tittclei
it con-
wllich
xv‘ct‘c
O’/i\l ,,o. 6. ~I‘hc3ptienl u;ts ;I (i(i-~c-;~~~-olcl\votn;itt ~\~lto pesetited witlt pin xitl ‘I st~tis;itic~tt ot w~irttitlt iii tlir IrCt sitk 01’ the f;ic~. Slir sttl~wcltictttl~ cltv4ol~~tl tlr\~i;rtiott c)t. the lefr eye tonged thr tttitllitw ;rtttl tliplopi~t. A c~otitl~uted
tlisph t*tl towat cl llir petipltt3.y 01 tlic cvtopl~isni (t:ig !I). ‘l’lle ;ttrttitvc ltttx‘ ;1t~tx2w~l blightI\ Iol~~rhtrtl. I’~tioclic acitl-SC-hit I’ sl;iitl t)ctorc antI at’trr di:tst;tsr cligvslion wcrc ttr+ttibr. Inititutiol~ct~o~itl;lse It*, tirticlws sttowetl pohitiw itttttiiittost~titiiti~ fat- .S- 100 l)tx~tviti mtl nc,ptive rcx tioti tot Lerdtiti. Stattis tot. ~itnrtttirt \vct’e fo(~alt~ l)ositi\,r. St;iitis li)t. tzi( Ior L’III. E:hI:1. ;ttitt NSE. \\ct.e tiegttiw itt the ttttttot~
totmtg’-;tpll\
cdl\.
01tcti
s(~;ltl
of’
the
hexl
\v:14 pet~fotIllrtl
atttl
~lloI\rtl
in;153 iii the tight tetnpot~;~ltmjott o\~et.l\itttg the lx)stct porliot~ of. tltr c;~vet~ttotts sinus. .4t slit-gct3, the 1Litiiot~ pea““1 htte.
~lltxhcd
to tttr
tILlI-;
, and
itnpittgetl
(;l-ossly. tltr ttt~qd;~sr~~mexutwl
on
the
4.0 cm
itt
;I
(:(I.\(, ,,o. 7.
icti. ;11)-
tit-51
petrous
ltte
gt-txtrst
ortd\
~~ws~ttlt’~l t)otl\. \vtieti
I tir with
palicwl ,Jac-Lsclttiatt
‘I tit* first s\tttptottts httt‘ csp2t~imcwl
\\a5
;I
4X-ytt--0ttl
,itt;tcks
ott
wottt;~tt rttc
lel’t
sitlc
who ol
tlatetl to 3 to I vc;it3 pi-c\iq)ivdra 01’ wrtigo that itt-
FIGURE 8. [Case no, 5) This tumor shows a great variation in size of the lipoblastic elements, but no anaplasra or other histologic suggestron of malrgnoncy. (Hematoxylin-eosin stain; magnification by150.)
LIPOBLASTIC MENINGIOMA (Lathes & Bigotti)
FIGURE 9. [Case no. 6) A fairly uniform population of vacuolated srgnet-ring cells. (Hematoxyirn-eosin stain magnificatron ’ 300.)
iirg:;rti\ c ill
I ht. 11101~~ 11pit-‘11, .I\; hell ,ij
ill the ~,cc~r~ol;~trtl. S~,IIIIS L,tlo~vetl nlotler~l~r t otl;kycii litx.1 Iortli;irion. Iiiinrur~o~~t~~o~i~l,lae lc( tlniclws rlicmt~tl iirg,iti\irk 01 ttw tiitt101. trll\ 101~ (,FAl’. keixtit~. h- IO(l. ,itl(I Shb:. III the 11,otx’ cl,is\ic rit~t~iti,~~~thc~lio~n~~tous tii~~iti~~giont.itoti~
11111101
,,,C‘lS.
,t;tiits
\tvit’
rtt.~;~\. ‘I richi-otrir
c
rlls
~\‘t~‘Ic
IO
Beside the classic nienin~othelial meningioma and the well-known variants, amon,g. which :11-t‘ the so-called fibroblastic, syncytial, transltlonal, :111dangiarid the less f‘requent but wellomatoid types, documented occurrence in meningioma of‘ heterologous elements, such as osteoid and cartilage.‘-3 there IS a much more un~~sual morphologic type of’ meningioma referred to in the literature as lipoblastic. vacuolated.‘.” or microcystic nieningioma.7X ‘IIe biologic behavior of’this variant is comparable to that of ordinary meningiomas. but its recognition bj, the pathologist is of‘ paramount importance because of’ the ease with which it call be mistaken f‘or liposarcoma, metastatic mutinous carcinoma, 01‘ even chordoma.” In this report, the clinicopathologic, histochemical, and immunohistochemical fatures of’ seven cases. collected at Columbia University College of Physicians and Surgeons (New York, NY), including one exceptional case of extracranial lipoblastic meningioma presenting as an intraorbital tumor, are reviewed. From the Department of Pathology. Di\ ision of Surgical Pathology. Columbia L!niversity (;ollegr of Physicians and Surgeons. 630 West 168th St. New ~‘oI-k. NY. Accepted fat- publication hIa) 15. IYYO. K interpreted as metast& signet-ring cell carcinoma. but. since no primarv tumor was found elsewhere. an exenteration of the left’ orbital contents was performed. The patient was subsequently fi)llowed fi)r I8 years. during which there were no signs of’ local recurrence or metastasis. No other primal-v tumor was discovered. On gross esamination, the turn& appeared as a well-circumscribed, apparently encapsulated. smooth-surtacecl. oval. sof‘t tan-colored mass. 3.5 X 2.j X 2.5 cm, located in the medial part of the orbit, apparentlv not adherent to the globe. The optic nerve was not grossly ‘in\A,ed by tumor. Microscopically, the tumor was a highly cellular tissue composed of’ vacuolated cells with a definite signet-ring appearance, arranged compactly in multiple lobules separated hy fibrovascular traheculae and muscle fihers (Figs I and 2). ‘I‘he nuclei were generally vesicular. hut occasionally hkarre and hyi)erchromatic. Some possible microscopic extensions ot the tumor into the surrounding tissues were seen (Fig 1). Mucicar164
LIPOBLASTIC MENINGIOMA (L&es
FIGURE 1. (Case no. 1) Photomicrograph of the tumor at its periphery, showing that It is made k~p predominantly of signet-ring cells. The capsule of the tumor cons& of compressed orbital tissue where some striated muscle fibers are entrapped in the reactive fibrous tissue. (Hematoxylin-eosin stain; magnificatiorl 1 100.)
drsc t-itwl.
Oil
norl\~rl).
;I tiliilor
in ttlt
FIGURE 2. (Case no. 1) The histologic features of the tumor at a higher power. Note that the signet-ring cells are fairly uniform In size, and that the nuclei are hyperchromatic but show no mitotic activity or bizarre shapes. (Hematoxylin-eosin stain; magnification * 300.)
165
& Blgottl)
HUMAN PATHOLOGY
Volume 22, No. 2 [February 1991)
FIGURE 3. [Case no. 1) Reticulin stains. Note the practically complete absence of reticulin fibrils between tumor cells, resulting in an epithelial-like pattern. (Wilder stain; magnification x 100.)
present (Fis 4). Mucirt and PAS stains were nrgativc. ‘1 richrotne starts showed scant\ collagett, especi;tlly atwttid blood vessels. Relic ulin stains outlined the rich v,tscularit\ and fine fihrils surtmuriclirig Iurnot- c.ell nests. Fat stairts 011 frozen sections revealed clef’irtite positivity of’ sortte but not all neoplastic elements. Neoplastic c-ells wtlh tnultiple small cytoplasrnic \acuoles were rtiore obviowly stained 1hart those with large. single vacuoles. rnatt who Cnsr 110. 3. The patient W;IS ;I 44vear-oltl began to complain of visual irnp;iirrttet;r 1 weel\ prior lo admission. On phyktl exatttirtatiott. positiw findings itteluded a blood pt~ss~rw of’ 150 over 100. 011 f’uttdust epic examination, bilateral papilledettta was ptwettr. with hrnorrhages on the left. A txaitt scan wis done, arid showetl ittcreased uptake of‘ radioactive isotope over the right t’rott-
tat ;it-ea. 11 righr catmtitl at~~t7iogr;tni was also perfortttrd, xnd twealecl 2 large, sharply citxxtrnscribed tumor ttiass in the right f’rotital at331 which stained ttotnogetteo~tsf~ with the dve. Surgrty bv;ts perfi)rrtied. arid, through ;I righ’ tl-orit;tl ctxtio~ottty, ;I I;irge I LIII~OI~ rttass attached ariterior.1~ to the fils was excised. (:otttr.ol of’ bleeding was initially trow t&3ottte. xitl there was xi estimated total blood loss of 3,000 ~111i. The pa&tit was alive and well H years aftet exe-ision. (~txxislv. Ihe tutnot‘ consisted of’ a large. 5.0 X 1.5 (tn. ni;iss weighing 3X g, globular iti shape, kidi otie flartetred side shtrwittg 5crarids of. brownish rissue on its surf’ace. ‘I‘he retttainder of‘ the surface w;ix fkirly smooth and soft. hlic-t~oscof~i~all~. the ttttttot‘ showed tttoderately wllulat tissur with ;I prortt~nettt \,asc-rtlarirv. The tumor tissue coiv
FIGURE 4. [Case no. 2) Note the association of typical meningothelial areas and lipoblastic areas with vacuolated signetring cells. There is considerable vascularity (Hematoxylin-eosin stain; magnification x 100.1
LIPOBIASTIC MENINGIOMA (Lattes & Bigotil)
FIGURE 5. (Case no. 3) Lipoblastic pattern. In this case, the vacuolated cells vary considerably in size and shape. There is, however, no anaplasia of the nuclei or detectabk? mltotic activity Some of the cells are multivacuolated. (Hematoxylineosin stain; magnification x 300.)
FIGURE 6. [Case no. 3) Another field showing a striking angiomatoid, almost hemangiopericytomatous, pattern. Vacuelated ceils are present but they are small and inconspicuous, (Hematoxylin-eosin stain; magnification \ 300.)
167
HUMAN PATHOLOGY
Volume 22, No. 2 (February 1991)
FIGURE 7. (Case no. 4) The lipoblostic component IS admixed with typical menrngothelial foci. (Hematoxylin-eosin stain; magnification n 100.) (Inset] A group of lipoblastrc cells whtch vary in size and shape, and are often multivacuolated. (Hematoxyin-eosin stain, magnificatron k 300.)
tli;tnietc~t~, sistul
01
n.15
t~Lrl~lx~t~\ ;ifttI
\;I( Liol,ttc.~l
trlls
xix\
bvitlt
Rlic t-oscopic~~ill~,
irrtitot~tit
tittclei
it con-
wllich
xv‘ct‘c
O’/i\l ,,o. 6. ~I‘hc3ptienl u;ts ;I (i(i-~c-;~~~-olcl\votn;itt ~\~lto pesetited witlt pin xitl ‘I st~tis;itic~tt ot w~irttitlt iii tlir IrCt sitk 01’ the f;ic~. Slir sttl~wcltictttl~ cltv4ol~~tl tlr\~i;rtiott c)t. the lefr eye tonged thr tttitllitw ;rtttl tliplopi~t. A c~otitl~uted
tlisph t*tl towat cl llir petipltt3.y 01 tlic cvtopl~isni (t:ig !I). ‘l’lle ;ttrttitvc ltttx‘ ;1t~tx2w~l blightI\ Iol~~rhtrtl. I’~tioclic acitl-SC-hit I’ sl;iitl t)ctorc antI at’trr di:tst;tsr cligvslion wcrc ttr+ttibr. Inititutiol~ct~o~itl;lse It*, tirticlws sttowetl pohitiw itttttiiittost~titiiti~ fat- .S- 100 l)tx~tviti mtl nc,ptive rcx tioti tot Lerdtiti. Stattis tot. ~itnrtttirt \vct’e fo(~alt~ l)ositi\,r. St;iitis li)t. tzi( Ior L’III. E:hI:1. ;ttitt NSE. \\ct.e tiegttiw itt the ttttttot~
totmtg’-;tpll\
cdl\.
01tcti
s(~;ltl
of’
the
hexl
\v:14 pet~fotIllrtl
atttl
~lloI\rtl
in;153 iii the tight tetnpot~;~ltmjott o\~et.l\itttg the lx)stct porliot~ of. tltr c;~vet~ttotts sinus. .4t slit-gct3, the 1Litiiot~ pea““1 htte.
~lltxhcd
to tttr
tILlI-;
, and
itnpittgetl
(;l-ossly. tltr ttt~qd;~sr~~mexutwl
on
the
4.0 cm
itt
;I
(:(I.\(, ,,o. 7.
icti. ;11)-
tit-51
petrous
ltte
gt-txtrst
ortd\
~~ws~ttlt’~l t)otl\. \vtieti
I tir with
palicwl ,Jac-Lsclttiatt
‘I tit* first s\tttptottts httt‘ csp2t~imcwl
\\a5
;I
4X-ytt--0ttl
,itt;tcks
ott
wottt;~tt rttc
lel’t
sitlc
who ol
tlatetl to 3 to I vc;it3 pi-c\iq)ivdra 01’ wrtigo that itt-
FIGURE 8. [Case no, 5) This tumor shows a great variation in size of the lipoblastic elements, but no anaplasra or other histologic suggestron of malrgnoncy. (Hematoxylin-eosin stain; magnification by150.)
LIPOBLASTIC MENINGIOMA (Lathes & Bigotti)
FIGURE 9. [Case no. 6) A fairly uniform population of vacuolated srgnet-ring cells. (Hematoxyirn-eosin stain magnificatron ’ 300.)
iirg:;rti\ c ill
I ht. 11101~~ 11pit-‘11, .I\; hell ,ij
ill the ~,cc~r~ol;~trtl. S~,IIIIS L,tlo~vetl nlotler~l~r t otl;kycii litx.1 Iortli;irion. Iiiinrur~o~~t~~o~i~l,lae lc( tlniclws rlicmt~tl iirg,iti\irk 01 ttw tiitt101. trll\ 101~ (,FAl’. keixtit~. h- IO(l. ,itl(I Shb:. III the 11,otx’ cl,is\ic rit~t~iti,~~~thc~lio~n~~tous tii~~iti~~giont.itoti~
11111101
,,,C‘lS.
,t;tiits
\tvit’
rtt.~;~\. ‘I richi-otrir
c
rlls
~\‘t~‘Ic
IO
