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Synchronous pituitary adenoma and pituicytoma
Synchronous Pituitary adenoma and Pituicytoma Marian C. Neidert M.D., Henning Leske M.D., Jan-Karl Burkhardt M.D., Spyros S. Kollias M.D., David Capper M.D., Daniel Schrimpf, Luca Regli M.D., Elisabeth J. Rushing M.D. PII: DOI: Reference:
S0046-8177(15)00323-8 doi: 10.1016/j.humpath.2015.08.017 YHUPA 3679
To appear in:
Human Pathology
Received date: Revised date: Accepted date:
3 July 2015 13 August 2015 26 August 2015
Please cite this article as: Neidert Marian C., Leske Henning, Burkhardt Jan-Karl, Kollias Spyros S., Capper David, Schrimpf Daniel, Regli Luca, Rushing Elisabeth J., Synchronous Pituitary adenoma and Pituicytoma, Human Pathology (2015), doi: 10.1016/j.humpath.2015.08.017
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT Case Report:
T
Synchronous Pituitary adenoma and Pituicytoma
RI P
Marian C. Neidert1, Henning Leske2, Jan-Karl Burkhardt1, Spyros S Kollias3, David
MA NU
SC
Capper4, Daniel Schrimpf4, Luca Regli1, Elisabeth J. Rushing2
1
Department of Neurosurgery, University Hospital Zurich, Switzerland
2
Department of Neuropathology, University Hospital Zurich, Switzerland
3
Department of Neuroradiology, University Hospital Zurich, Switzerland
4
ED
Department of Neuropathology, University Hospital Heidelberg and German Cancer
PT
Consortium (DKTK), CCU Neuropathology, German Cancer Research Center
AC
CE
(DKFZ), Heidelberg, Germany
Corresponding author: Prof. Elisabeth J. Rushing, MD Department of Neuropathology University Hospital Zurich, Switzerland Schmelzbergstrasse 12 CH-8091 Zurich, Switzerland
ACCEPTED MANUSCRIPT Abstract
Pituicytoma is a rare benign neoplasm arising in the sellar region, usually found in the
T
posterior lobe, and /or pituitary stalk. Here we report the case of a 67 year-old female
RI P
who presented with bitemporal hemianopsia and visual impairment accompanied by mildly elevated prolactin. Pathological and molecular examination of the tissue
SC
removed transsphenoidally revealed two distinct tumors: pituitary adenoma and
MA NU
pituicytoma. To the best of our knowledge, histologically proven pituicytoma and
CE
PT
ED
pituitary adenoma have never been reported together.
AC
Key words: pituitary adenoma; MRI; pituicytoma; pituicyte; TTF1
ACCEPTED MANUSCRIPT 1. Introduction Pituicytoma is a rare benign neoplasm arising in the sellar region, usually found in the
T
posterior lobe, and /or pituitary stalk. Although these tumors may present at any age,
RI P
they dominate during adulthood and show a slight male predilection (1, 2). The exact incidence is not known since only a small number of case reports and small case Clinically,
SC
series (in total approximately 70 cases) have been published (2).
pituicytomas mimic nonfunctioning pituitary macroadenomas with visual field defects,
MA NU
hypopituitarism and headaches, although occasionally such tumors are discovered incidentally at autopsy (3). Obesity has been described in a small series of patients (4). Spontaneous suprasellar hemorrhage due to a pituicytoma has been the subject of a single case report (5). Rare associations with other endocrine neoplasms such
ED
as parathyroid adenoma and follicular thyroid carcinoma are recognized (6). Here we
PT
present the case of a 67 year-old female who presented with bitemporal hemianopsia and visual impairment accompanied by mildly elevated prolactin.
Pathological
CE
examination of the tissue removed transsphenoidally revealed two distinct tumors:
AC
pituitary adenoma and pituicytoma. To the best of our knowledge, histologically proven pituicytoma and pituitary adenoma have never been reported together.
ACCEPTED MANUSCRIPT 2. Case report A 67 year-old female with an uneventful past medical history was admitted to the
T
Department of Neurosurgery, University of Zurich, for the treatment of an intra- and
RI P
suprasellar lesion. The patient had noted a 6-month history of increasing visual impairment and headaches accompanied by visual field restriction; however, no
SC
symptoms of endocrine dysfunction were reported. Family history was remarkable for a sister who was diagnosed with thyroid carcinoma at the age of 20. Neurological
MA NU
examination was notable for bitemporal hemianopsia. Ophthalmological examination showed a visual acuity (without correction) of 0.4 in the left eye and 0.6 in the right eye as well as bitemporal visual field cuts (left > right) on perimetric examination. Magnetic resonance imaging (MRI) revealed a space-occupying contrast-enhancing
ED
sellar and suprasellar mass (2.5 cm cranio-caudally dimension and 2 x 1.5 cm in
PT
transversal planes) with compression of the optic chiasm (see Figure 1 A and B). Preoperative serum prolactin was mildly elevated at 46µg/dl consistent with pituitary
CE
stalk compression rather than prolactin production by the lesion. The findings were
AC
strongly suggestive of a nonfunctioning pituitary adenoma. Endoscopic surgery was performed via a transsphenoidal approach. Intraoperative 3T Tesla MRI showed a small residual at the lateral wall of the right cavernous sinus (see Figure 1 D), which could be resected in the same session.
The patient
experienced an uneventful postoperative course. At three months follow-up the visual deficits recovered completely and imaging follow-up did not show any residual tumor (Figure 1 E and F).
ACCEPTED MANUSCRIPT 3. Pathological examination
T
3.1 Histopathology
RI P
Two separate specimens were submitted for evaluation. The first specimen consisted of multiple small, firm beige tissue fragments measuring 15x15x5 mm, whereas the
SC
second specimen measured 10mm in maximum diameter. Microscopic examination of the first specimen revealed two morphologically distinct neoplasms along with
MA NU
fragments of nontumorous adenohypophysial parenchyma (Figure 2). The second specimen contained fragments of nontumorous pituitary. On Gomori reticulin-stained sections, the adenoma showed characteristic effacement of the reticulin network, whereas fragments of nontumorous pituitary and the second tumor were reticulin-
ED
rich, with reticulin outlining the dense capillary bed within the tumor. The adenoma
PT
consisted of closely packed monomorphic, epithelial-appearing cells that stained diffusely with synaptophysin, but were nonreactive for all pituitary hormones, TTF1,
CE
epithelial membrane antigen (EMA), S100 protein, galectin3 and glial fibrillary protein
AC
(GFAP) and BCL2. In contrast, the tumor cells of the second tumor, which were arranged in compact fascicles and composed of plump, bipolar spindle cells, were negative for synaptophysin. Rosenthal fibers, eosinophilic granular bodies and calcifications were not seen. The nuclei of the spindle cell neoplasm stained with thyroid transcription factor-1 (TTF1). Focal cytoplasmic EMA, galectin3 and GFAP positivity and strong diffuse cytoplasmic expression of BCL2 and S100 were also observed. The MIB1 (Ki67) proliferation index was 3% in the adenoma and 6% in the spindle cell neoplasm.
On the basis of the morphological features and
immunohistochemical profile, the diagnoses of pituitary adenoma without hormone expression, and pituicytoma, were confirmed.
ACCEPTED MANUSCRIPT 3.2 DNA methylation profiling For further molecular characterization, DNA was extracted separately for both tumors
T
from FFPE material using the automated Maxwell system (Promega, Madison, WI,
RI P
USA). The DNA methylation status of over 450.000 CpG sites was analyzed at the Core Facility of the DKFZ with the Illumina Infinium HumanMethylation450 (450k)
SC
array (Illumina, San Diego, CA, USA) according to the manufacturer’s instructions. Unsupervized hierarchical clustering of both tumors was performed together with
MA NU
DNA methylation profiles of 8 histologically confirmed pituicytomas and 10 pituitary adenomas (Figure 3A). For this clustering only CpGs with a standard deviation greater 0.2 across the beta values were selected. The samples were clustered with Ward’s linkage method and the pairwise similarity was calculated using the Euclidian
ED
distance. For the hierarchical clustering of the CpGs average linkage and the
PT
Euclidian distance were applied.
The clustering profile showed a clear clustering of the pituicytoma with 9 other
CE
pituicytomas and of the adenoma with the group of other 10 adenomas (Figure 3A).
AC
Further, copy number plots were calculated from the DNA methylation data as described in (7). While the adenoma does not have chromosomal imbalances, the pituicytoma shows numerous chromosomal gains and losses indicated by the shifting of whole chromosomes on the y axis on the copy number plot (e.g. gains of chromosome 4 and 5 and losses of 9, 10, 12, 13 and 15) (Figure 3B).
4. Discussion Pituicytomas originate from pituicytes, which are considered to represent specialized glia of the neurohypophysis (8). In fact, those unfamiliar with the entity have a tendency to regard it as pilocytic astrocytoma, the principle morphological differential diagnosis. The distinctive immunoprofile and the absence of a biphasic pattern,
ACCEPTED MANUSCRIPT Rosenthal fibers and eosinophilic granular bodies as seen in pilocytic astrocytomas facilitate the correct diagnosis of pituicytoma. In the past, pituicytoma was
T
distinguished from two additional non-adenomatous, primary pituitary tumors, the
RI P
spindle cell oncocytoma and the granular cell tumor of the neurohypophysis. Recent studies, however, support the notion that despite their morphologic diversity,
SC
pituicytomas, granular cell tumors and spindle cell oncocytoma represent phenotypic variants of the same entity and therefore share a common pituicyte lineage.
MA NU
Accordingly, the term pituicytoma now embraces a continuum of lesions with “oncocytic and “granular cell” subtypes (9). Evidence supporting the concept that these three morphologic variants represent the same tumor category is derived from common ultrastructural features and immunolabeling with TTF1, a transcription factor
ED
involved in the morphogenesis and differentiation of thyroid, lung and ventral
PT
forebrain (10). Based on shared TTF1-expression, it also has been postulated that chordoid glioma of the third ventricle and pituicytoma may form part of a spectrum of
AC
CE
lineage-related tumors of the basal forebrain (11).
Given the rarity of these tumors, it is not surprising that the molecular characterization remains a work in progress. Recently DNA methylation profiles have shown great potential for the classification of various types of brain tumors. We performed a DNA methylation analysis separately for the pituicytoma and pituitary adenoma and could demonstrate that both tumors show a distinct methylation profile. In addition, we found that the methylation profile of the patient’s pituicytoma resembles other pituicytomas and that pituitary adenomas shows a close relation to other pituitary adenomas. This clearly indicates that both lesions represent different tumors at the molecular level. Additional evidence can be derived from comparing the copy number profiles calculated from the 450k array data. Here the pituicytoma
ACCEPTED MANUSCRIPT shows numerous chromosomal imbalances whereas the pituitary adenoma shows a balanced profile. This observation provides compelling evidence for the independent
T
nature and development of both tumors.
RI P
For the most part, the neuroimaging features of pituicytoma overlap with other entities found in the sellar and suprasellar region, thus precluding a preoperative
SC
high index of suspicion (1, 12). An adequate imaging procedure is mandatory for the characterization of these tumors and for the differential diagnosis with other potential
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lesions of the hypothalamic-pituitary region. On computed tomography (CT) scans, pituicytoma appears as a solid, well demarcated, hyperdense with rare calcifications and enhancing mass that may occupy the sellar region, including the suprasellar space. Magnetic resonance (MR) imaging usually shows a solid, discrete, contrast-
ED
enhancing pituitary mass, iso-intense on T1-weighted images and hyperintense on
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T2 and proton- density images. Sometimes dynamic contrast enhanced MR study
AC
lesion (13).
CE
may show rapid and early enhancement as an expression of a highly vascularized
Pituicytomas are considered completely benign and do not undergo malignant transformation. Nevertheless, incompletely resected tumors may recur. In the series by Brat, two partially resected tumors recurred. Another recent publication suggested that the spindle cell oncocytic subtype exhibits a more infiltrative growth and therefore more challenging to completely resect (2).
The role of additional
therapeutic measures in incomplete resected tumors is difficult to adequately assess due to the limited number of cases. Pituicytoma has been reported to occur with other endocrine neoplasms such as parathyroid adenoma and follicular thyroid carcinoma (6) however concomitant sellar lesions have not been described. There is a single case report on a patient with a
ACCEPTED MANUSCRIPT pituicytoma in the presence of Cushing`s disease, however a pituitary adenoma could not be confirmed histologically in this patient (14). Pituitary adenomas can
T
occur with other sellar pathologies and the term “collision sellar lesions” has been
arachnoid
cyst,
epidermoid
cyst,
intrasellar
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coined for this rare entity (15). Rathke`s cleft cyst, craniopharyngioma, collid cyst, Schwannoma,
gangliocytoma,
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lymphocytic hypophysitis, granulomatous hypophysitis, sarcoidosis, and double pituitary adenoma are the pathologies reported in concomitance with pituitary
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adenomas (15). To the best of our knowledge, we describe the first report of a
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CE
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ED
histologically proven pituitary adenoma associated with a pituicytoma.
ACCEPTED MANUSCRIPT References 1.
Covington MF, Chin SS, Osborn AG. Pituicytoma, spindle cell oncocytoma,
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and granular cell tumor: clarification and meta-analysis of the world literature since
2.
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1893. AJNR American journal of neuroradiology 2011; 32, 2067-2072. Zygourakis CC, Rolston JD, Lee HS, Partow C, Kunwar S, Aghi MK.
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Pituicytomas and spindle cell oncocytomas: modern case series from the University of California, San Francisco. Pituitary 2015; 18, 150-158.
Takei H, Goodman JC, Tanaka S, Bhattacharjee MB, Bahrami A, Powell SZ.
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3.
Pituicytoma incidentally found at autopsy. Pathology international 2005; 55, 745-749. 4.
Teti C, Castelletti L, Allegretti L, Talco M, Zona G, Minuto F, Boschetti M,
Ferone D. Pituitary image: pituicytoma. Pituitary 2014. Benveniste RJ, Purohit D, Byun H. Pituicytoma presenting with spontaneous
ED
5.
6.
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hemorrhage. Pituitary 2006; 9, 53-58.
Schultz AB, Brat DJ, Oyesiku NM, Hunter SB. Intrasellar pituicytoma in a
CE
patient with other endocrine neoplasms. Archives of pathology & laboratory medicine
7.
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2001; 125, 527-530.
Hovestadt V, Remke M, Kool M, Pietsch T, Northcott PA, Fischer R, Cavalli
FM, Ramaswamy V, Zapatka M, Reifenberger G, Rutkowski S, Schick M, Bewerunge-Hudler M, Korshunov A, Lichter P, Taylor MD, Pfister SM, Jones DT. Robust molecular subgrouping and copy-number profiling of medulloblastoma from small amounts of archival tumour material using high-density DNA methylation arrays. Acta neuropathologica 2013; 125, 913-916. 8.
Brat DJ, Scheithauer BW, Staugaitis SM, Holtzman RN, Morgello S, Burger
PC. Pituicytoma: a distinctive low-grade glioma of the neurohypophysis. The American journal of surgical pathology 2000; 24, 362-368.
ACCEPTED MANUSCRIPT 9.
Mete O, Lopes MB, Asa SL. Spindle cell oncocytomas and granular cell
tumors of the pituitary are variants of pituicytoma. The American journal of surgical
Lee EB, Tihan T, Scheithauer BW, Zhang PJ, Gonatas NK. Thyroid
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10.
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pathology 2013; 37, 1694-1699.
transcription factor 1 expression in sellar tumors: a histogenetic marker? Journal of
11.
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neuropathology and experimental neurology 2009; 68, 482-488.
Hewer E, Beck J, Kellner-Weldon F, Vajtai I. Suprasellar chordoid neoplasm
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with expression of thyroid transcription factor 1: evidence that chordoid glioma of the third ventricle and pituicytoma may form part of a spectrum of lineage-related tumors of the basal forebrain. Human pathology 2015; 46, 1045-1049. 12.
Hammoud DA, Munter FM, Brat DJ, Pomper MG. Magnetic resonance imaging
ED
features of pituicytomas: analysis of 10 cases. Journal of computer assisted
Secci F, Merciadri P, Rossi DC, D'Andrea A, Zona G. Pituicytomas:
radiological
findings,
clinical
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13.
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tomography 2010; 34, 757-761.
behavior
and
surgical
management.
Acta
14.
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neurochirurgica 2012; 154, 649-657; discussion 657. Schmalisch K, Schittenhelm J, Ebner FH, Beuschlein F, Honegger J,
Beschorner R. Pituicytoma in a patient with Cushing's disease: case report and review of the literature. Pituitary 2012; 15 Suppl 1, S10-16. 15.
Koutourousiou M, Kontogeorgos G, Wesseling P, Grotenhuis AJ, Seretis A.
Collision sellar lesions: experience with eight cases and review of the literature. Pituitary 2010; 13, 8-17.
ACCEPTED MANUSCRIPT Figure Legends Figure 1. (A) Coronal and (B) sagittal sections of the preoperative T1-weighted and
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contrast-enhanced MRI. (C) Coronal T2-weighted and (D) coronal T1-weighted,
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contrast-enhanced intraoperative 3T MRI. (E) Coronal T2-weighted and (F) coronal
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T1-weighted, contrast-enhanced MRI at 3-months follow-up.
Figure 2.
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Panel 1: H&E (A) as well as immunohistochemical stains for synaptophysin (B), S100 (C), galectin 3 (D), and BCL2 (E), highlight the distinct morphological and immunohistochemical features of the pituitary adenoma in the upper half compared to the pituicytoma in the lower half of the sections. (1x)
ED
Panel 2: On higher magnification, the pituitary adenoma is a monomorphic neoplasm
PT
(H&E) (A) that expands the normal lobular structure, as highlighted in the reticulin stain (B) and lacking nuclear positivity for TTF1 (C). In contrast, pituicytoma is
CE
composed of closely apposed spindle cells organized in interlacing fascicles (H&E)
TTF1 (F).
AC
(D) and accompanied by a reticulin-rich stroma (E) with diffuse nuclear positivity for
Figure 3. (A) Unsupervised cluster analysis of 450k methylation data of both tumors of this patient (indicated in black) with 8 classical pituicytomas and 10 pituitary adenomas. As expected the pituicytoma clustered within the group of pituicytomas on the left and the adenoma clustered among the group of adenomas. (B) Comparison of the copy number profiles calculated from the DNA methylation data demonstrates a balances profile for the adenoma and multiple chromosomal gains and losses for the pituicytoma giving further evidence for the separate biological nature of both lesions.
ACCEPTED MANUSCRIPT
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Figure 1
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Figure 2
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Figure 3
ACCEPTED MANUSCRIPT Highlights We report the first case of synchronous pituicytoma and pituitary adenoma.
-
Histopathological work-up revealed two distinct tumors.
-
DNA methylation profiling indicates that both lesions represent different tumor
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T
-
AC
CE
PT
ED
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SC
entities.
S0046-8177(15)00323-8 doi: 10.1016/j.humpath.2015.08.017 YHUPA 3679
To appear in:
Human Pathology
Received date: Revised date: Accepted date:
3 July 2015 13 August 2015 26 August 2015
Please cite this article as: Neidert Marian C., Leske Henning, Burkhardt Jan-Karl, Kollias Spyros S., Capper David, Schrimpf Daniel, Regli Luca, Rushing Elisabeth J., Synchronous Pituitary adenoma and Pituicytoma, Human Pathology (2015), doi: 10.1016/j.humpath.2015.08.017
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT Case Report:
T
Synchronous Pituitary adenoma and Pituicytoma
RI P
Marian C. Neidert1, Henning Leske2, Jan-Karl Burkhardt1, Spyros S Kollias3, David
MA NU
SC
Capper4, Daniel Schrimpf4, Luca Regli1, Elisabeth J. Rushing2
1
Department of Neurosurgery, University Hospital Zurich, Switzerland
2
Department of Neuropathology, University Hospital Zurich, Switzerland
3
Department of Neuroradiology, University Hospital Zurich, Switzerland
4
ED
Department of Neuropathology, University Hospital Heidelberg and German Cancer
PT
Consortium (DKTK), CCU Neuropathology, German Cancer Research Center
AC
CE
(DKFZ), Heidelberg, Germany
Corresponding author: Prof. Elisabeth J. Rushing, MD Department of Neuropathology University Hospital Zurich, Switzerland Schmelzbergstrasse 12 CH-8091 Zurich, Switzerland
ACCEPTED MANUSCRIPT Abstract
Pituicytoma is a rare benign neoplasm arising in the sellar region, usually found in the
T
posterior lobe, and /or pituitary stalk. Here we report the case of a 67 year-old female
RI P
who presented with bitemporal hemianopsia and visual impairment accompanied by mildly elevated prolactin. Pathological and molecular examination of the tissue
SC
removed transsphenoidally revealed two distinct tumors: pituitary adenoma and
MA NU
pituicytoma. To the best of our knowledge, histologically proven pituicytoma and
CE
PT
ED
pituitary adenoma have never been reported together.
AC
Key words: pituitary adenoma; MRI; pituicytoma; pituicyte; TTF1
ACCEPTED MANUSCRIPT 1. Introduction Pituicytoma is a rare benign neoplasm arising in the sellar region, usually found in the
T
posterior lobe, and /or pituitary stalk. Although these tumors may present at any age,
RI P
they dominate during adulthood and show a slight male predilection (1, 2). The exact incidence is not known since only a small number of case reports and small case Clinically,
SC
series (in total approximately 70 cases) have been published (2).
pituicytomas mimic nonfunctioning pituitary macroadenomas with visual field defects,
MA NU
hypopituitarism and headaches, although occasionally such tumors are discovered incidentally at autopsy (3). Obesity has been described in a small series of patients (4). Spontaneous suprasellar hemorrhage due to a pituicytoma has been the subject of a single case report (5). Rare associations with other endocrine neoplasms such
ED
as parathyroid adenoma and follicular thyroid carcinoma are recognized (6). Here we
PT
present the case of a 67 year-old female who presented with bitemporal hemianopsia and visual impairment accompanied by mildly elevated prolactin.
Pathological
CE
examination of the tissue removed transsphenoidally revealed two distinct tumors:
AC
pituitary adenoma and pituicytoma. To the best of our knowledge, histologically proven pituicytoma and pituitary adenoma have never been reported together.
ACCEPTED MANUSCRIPT 2. Case report A 67 year-old female with an uneventful past medical history was admitted to the
T
Department of Neurosurgery, University of Zurich, for the treatment of an intra- and
RI P
suprasellar lesion. The patient had noted a 6-month history of increasing visual impairment and headaches accompanied by visual field restriction; however, no
SC
symptoms of endocrine dysfunction were reported. Family history was remarkable for a sister who was diagnosed with thyroid carcinoma at the age of 20. Neurological
MA NU
examination was notable for bitemporal hemianopsia. Ophthalmological examination showed a visual acuity (without correction) of 0.4 in the left eye and 0.6 in the right eye as well as bitemporal visual field cuts (left > right) on perimetric examination. Magnetic resonance imaging (MRI) revealed a space-occupying contrast-enhancing
ED
sellar and suprasellar mass (2.5 cm cranio-caudally dimension and 2 x 1.5 cm in
PT
transversal planes) with compression of the optic chiasm (see Figure 1 A and B). Preoperative serum prolactin was mildly elevated at 46µg/dl consistent with pituitary
CE
stalk compression rather than prolactin production by the lesion. The findings were
AC
strongly suggestive of a nonfunctioning pituitary adenoma. Endoscopic surgery was performed via a transsphenoidal approach. Intraoperative 3T Tesla MRI showed a small residual at the lateral wall of the right cavernous sinus (see Figure 1 D), which could be resected in the same session.
The patient
experienced an uneventful postoperative course. At three months follow-up the visual deficits recovered completely and imaging follow-up did not show any residual tumor (Figure 1 E and F).
ACCEPTED MANUSCRIPT 3. Pathological examination
T
3.1 Histopathology
RI P
Two separate specimens were submitted for evaluation. The first specimen consisted of multiple small, firm beige tissue fragments measuring 15x15x5 mm, whereas the
SC
second specimen measured 10mm in maximum diameter. Microscopic examination of the first specimen revealed two morphologically distinct neoplasms along with
MA NU
fragments of nontumorous adenohypophysial parenchyma (Figure 2). The second specimen contained fragments of nontumorous pituitary. On Gomori reticulin-stained sections, the adenoma showed characteristic effacement of the reticulin network, whereas fragments of nontumorous pituitary and the second tumor were reticulin-
ED
rich, with reticulin outlining the dense capillary bed within the tumor. The adenoma
PT
consisted of closely packed monomorphic, epithelial-appearing cells that stained diffusely with synaptophysin, but were nonreactive for all pituitary hormones, TTF1,
CE
epithelial membrane antigen (EMA), S100 protein, galectin3 and glial fibrillary protein
AC
(GFAP) and BCL2. In contrast, the tumor cells of the second tumor, which were arranged in compact fascicles and composed of plump, bipolar spindle cells, were negative for synaptophysin. Rosenthal fibers, eosinophilic granular bodies and calcifications were not seen. The nuclei of the spindle cell neoplasm stained with thyroid transcription factor-1 (TTF1). Focal cytoplasmic EMA, galectin3 and GFAP positivity and strong diffuse cytoplasmic expression of BCL2 and S100 were also observed. The MIB1 (Ki67) proliferation index was 3% in the adenoma and 6% in the spindle cell neoplasm.
On the basis of the morphological features and
immunohistochemical profile, the diagnoses of pituitary adenoma without hormone expression, and pituicytoma, were confirmed.
ACCEPTED MANUSCRIPT 3.2 DNA methylation profiling For further molecular characterization, DNA was extracted separately for both tumors
T
from FFPE material using the automated Maxwell system (Promega, Madison, WI,
RI P
USA). The DNA methylation status of over 450.000 CpG sites was analyzed at the Core Facility of the DKFZ with the Illumina Infinium HumanMethylation450 (450k)
SC
array (Illumina, San Diego, CA, USA) according to the manufacturer’s instructions. Unsupervized hierarchical clustering of both tumors was performed together with
MA NU
DNA methylation profiles of 8 histologically confirmed pituicytomas and 10 pituitary adenomas (Figure 3A). For this clustering only CpGs with a standard deviation greater 0.2 across the beta values were selected. The samples were clustered with Ward’s linkage method and the pairwise similarity was calculated using the Euclidian
ED
distance. For the hierarchical clustering of the CpGs average linkage and the
PT
Euclidian distance were applied.
The clustering profile showed a clear clustering of the pituicytoma with 9 other
CE
pituicytomas and of the adenoma with the group of other 10 adenomas (Figure 3A).
AC
Further, copy number plots were calculated from the DNA methylation data as described in (7). While the adenoma does not have chromosomal imbalances, the pituicytoma shows numerous chromosomal gains and losses indicated by the shifting of whole chromosomes on the y axis on the copy number plot (e.g. gains of chromosome 4 and 5 and losses of 9, 10, 12, 13 and 15) (Figure 3B).
4. Discussion Pituicytomas originate from pituicytes, which are considered to represent specialized glia of the neurohypophysis (8). In fact, those unfamiliar with the entity have a tendency to regard it as pilocytic astrocytoma, the principle morphological differential diagnosis. The distinctive immunoprofile and the absence of a biphasic pattern,
ACCEPTED MANUSCRIPT Rosenthal fibers and eosinophilic granular bodies as seen in pilocytic astrocytomas facilitate the correct diagnosis of pituicytoma. In the past, pituicytoma was
T
distinguished from two additional non-adenomatous, primary pituitary tumors, the
RI P
spindle cell oncocytoma and the granular cell tumor of the neurohypophysis. Recent studies, however, support the notion that despite their morphologic diversity,
SC
pituicytomas, granular cell tumors and spindle cell oncocytoma represent phenotypic variants of the same entity and therefore share a common pituicyte lineage.
MA NU
Accordingly, the term pituicytoma now embraces a continuum of lesions with “oncocytic and “granular cell” subtypes (9). Evidence supporting the concept that these three morphologic variants represent the same tumor category is derived from common ultrastructural features and immunolabeling with TTF1, a transcription factor
ED
involved in the morphogenesis and differentiation of thyroid, lung and ventral
PT
forebrain (10). Based on shared TTF1-expression, it also has been postulated that chordoid glioma of the third ventricle and pituicytoma may form part of a spectrum of
AC
CE
lineage-related tumors of the basal forebrain (11).
Given the rarity of these tumors, it is not surprising that the molecular characterization remains a work in progress. Recently DNA methylation profiles have shown great potential for the classification of various types of brain tumors. We performed a DNA methylation analysis separately for the pituicytoma and pituitary adenoma and could demonstrate that both tumors show a distinct methylation profile. In addition, we found that the methylation profile of the patient’s pituicytoma resembles other pituicytomas and that pituitary adenomas shows a close relation to other pituitary adenomas. This clearly indicates that both lesions represent different tumors at the molecular level. Additional evidence can be derived from comparing the copy number profiles calculated from the 450k array data. Here the pituicytoma
ACCEPTED MANUSCRIPT shows numerous chromosomal imbalances whereas the pituitary adenoma shows a balanced profile. This observation provides compelling evidence for the independent
T
nature and development of both tumors.
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For the most part, the neuroimaging features of pituicytoma overlap with other entities found in the sellar and suprasellar region, thus precluding a preoperative
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high index of suspicion (1, 12). An adequate imaging procedure is mandatory for the characterization of these tumors and for the differential diagnosis with other potential
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lesions of the hypothalamic-pituitary region. On computed tomography (CT) scans, pituicytoma appears as a solid, well demarcated, hyperdense with rare calcifications and enhancing mass that may occupy the sellar region, including the suprasellar space. Magnetic resonance (MR) imaging usually shows a solid, discrete, contrast-
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enhancing pituitary mass, iso-intense on T1-weighted images and hyperintense on
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T2 and proton- density images. Sometimes dynamic contrast enhanced MR study
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lesion (13).
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may show rapid and early enhancement as an expression of a highly vascularized
Pituicytomas are considered completely benign and do not undergo malignant transformation. Nevertheless, incompletely resected tumors may recur. In the series by Brat, two partially resected tumors recurred. Another recent publication suggested that the spindle cell oncocytic subtype exhibits a more infiltrative growth and therefore more challenging to completely resect (2).
The role of additional
therapeutic measures in incomplete resected tumors is difficult to adequately assess due to the limited number of cases. Pituicytoma has been reported to occur with other endocrine neoplasms such as parathyroid adenoma and follicular thyroid carcinoma (6) however concomitant sellar lesions have not been described. There is a single case report on a patient with a
ACCEPTED MANUSCRIPT pituicytoma in the presence of Cushing`s disease, however a pituitary adenoma could not be confirmed histologically in this patient (14). Pituitary adenomas can
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occur with other sellar pathologies and the term “collision sellar lesions” has been
arachnoid
cyst,
epidermoid
cyst,
intrasellar
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coined for this rare entity (15). Rathke`s cleft cyst, craniopharyngioma, collid cyst, Schwannoma,
gangliocytoma,
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lymphocytic hypophysitis, granulomatous hypophysitis, sarcoidosis, and double pituitary adenoma are the pathologies reported in concomitance with pituitary
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adenomas (15). To the best of our knowledge, we describe the first report of a
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histologically proven pituitary adenoma associated with a pituicytoma.
ACCEPTED MANUSCRIPT References 1.
Covington MF, Chin SS, Osborn AG. Pituicytoma, spindle cell oncocytoma,
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and granular cell tumor: clarification and meta-analysis of the world literature since
2.
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1893. AJNR American journal of neuroradiology 2011; 32, 2067-2072. Zygourakis CC, Rolston JD, Lee HS, Partow C, Kunwar S, Aghi MK.
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Pituicytomas and spindle cell oncocytomas: modern case series from the University of California, San Francisco. Pituitary 2015; 18, 150-158.
Takei H, Goodman JC, Tanaka S, Bhattacharjee MB, Bahrami A, Powell SZ.
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3.
Pituicytoma incidentally found at autopsy. Pathology international 2005; 55, 745-749. 4.
Teti C, Castelletti L, Allegretti L, Talco M, Zona G, Minuto F, Boschetti M,
Ferone D. Pituitary image: pituicytoma. Pituitary 2014. Benveniste RJ, Purohit D, Byun H. Pituicytoma presenting with spontaneous
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5.
6.
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hemorrhage. Pituitary 2006; 9, 53-58.
Schultz AB, Brat DJ, Oyesiku NM, Hunter SB. Intrasellar pituicytoma in a
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patient with other endocrine neoplasms. Archives of pathology & laboratory medicine
7.
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2001; 125, 527-530.
Hovestadt V, Remke M, Kool M, Pietsch T, Northcott PA, Fischer R, Cavalli
FM, Ramaswamy V, Zapatka M, Reifenberger G, Rutkowski S, Schick M, Bewerunge-Hudler M, Korshunov A, Lichter P, Taylor MD, Pfister SM, Jones DT. Robust molecular subgrouping and copy-number profiling of medulloblastoma from small amounts of archival tumour material using high-density DNA methylation arrays. Acta neuropathologica 2013; 125, 913-916. 8.
Brat DJ, Scheithauer BW, Staugaitis SM, Holtzman RN, Morgello S, Burger
PC. Pituicytoma: a distinctive low-grade glioma of the neurohypophysis. The American journal of surgical pathology 2000; 24, 362-368.
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Mete O, Lopes MB, Asa SL. Spindle cell oncocytomas and granular cell
tumors of the pituitary are variants of pituicytoma. The American journal of surgical
Lee EB, Tihan T, Scheithauer BW, Zhang PJ, Gonatas NK. Thyroid
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10.
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pathology 2013; 37, 1694-1699.
transcription factor 1 expression in sellar tumors: a histogenetic marker? Journal of
11.
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neuropathology and experimental neurology 2009; 68, 482-488.
Hewer E, Beck J, Kellner-Weldon F, Vajtai I. Suprasellar chordoid neoplasm
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with expression of thyroid transcription factor 1: evidence that chordoid glioma of the third ventricle and pituicytoma may form part of a spectrum of lineage-related tumors of the basal forebrain. Human pathology 2015; 46, 1045-1049. 12.
Hammoud DA, Munter FM, Brat DJ, Pomper MG. Magnetic resonance imaging
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features of pituicytomas: analysis of 10 cases. Journal of computer assisted
Secci F, Merciadri P, Rossi DC, D'Andrea A, Zona G. Pituicytomas:
radiological
findings,
clinical
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13.
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tomography 2010; 34, 757-761.
behavior
and
surgical
management.
Acta
14.
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neurochirurgica 2012; 154, 649-657; discussion 657. Schmalisch K, Schittenhelm J, Ebner FH, Beuschlein F, Honegger J,
Beschorner R. Pituicytoma in a patient with Cushing's disease: case report and review of the literature. Pituitary 2012; 15 Suppl 1, S10-16. 15.
Koutourousiou M, Kontogeorgos G, Wesseling P, Grotenhuis AJ, Seretis A.
Collision sellar lesions: experience with eight cases and review of the literature. Pituitary 2010; 13, 8-17.
ACCEPTED MANUSCRIPT Figure Legends Figure 1. (A) Coronal and (B) sagittal sections of the preoperative T1-weighted and
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contrast-enhanced MRI. (C) Coronal T2-weighted and (D) coronal T1-weighted,
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contrast-enhanced intraoperative 3T MRI. (E) Coronal T2-weighted and (F) coronal
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T1-weighted, contrast-enhanced MRI at 3-months follow-up.
Figure 2.
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Panel 1: H&E (A) as well as immunohistochemical stains for synaptophysin (B), S100 (C), galectin 3 (D), and BCL2 (E), highlight the distinct morphological and immunohistochemical features of the pituitary adenoma in the upper half compared to the pituicytoma in the lower half of the sections. (1x)
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Panel 2: On higher magnification, the pituitary adenoma is a monomorphic neoplasm
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(H&E) (A) that expands the normal lobular structure, as highlighted in the reticulin stain (B) and lacking nuclear positivity for TTF1 (C). In contrast, pituicytoma is
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composed of closely apposed spindle cells organized in interlacing fascicles (H&E)
TTF1 (F).
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(D) and accompanied by a reticulin-rich stroma (E) with diffuse nuclear positivity for
Figure 3. (A) Unsupervised cluster analysis of 450k methylation data of both tumors of this patient (indicated in black) with 8 classical pituicytomas and 10 pituitary adenomas. As expected the pituicytoma clustered within the group of pituicytomas on the left and the adenoma clustered among the group of adenomas. (B) Comparison of the copy number profiles calculated from the DNA methylation data demonstrates a balances profile for the adenoma and multiple chromosomal gains and losses for the pituicytoma giving further evidence for the separate biological nature of both lesions.
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ACCEPTED MANUSCRIPT Highlights We report the first case of synchronous pituicytoma and pituitary adenoma.
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Histopathological work-up revealed two distinct tumors.
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DNA methylation profiling indicates that both lesions represent different tumor
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entities.