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Suprasellar spindle cell lipoma
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Annals of Diagnostic Pathology 13 (2009) 173 – 175
Radiologic-Pathologic Correlation
Suprasellar spindle cell lipoma Krista L. Pekarski, MD, Richard A. Prayson, MD⁎ Cleveland Clinic Foundation, Institute of Pathology, Cleveland, OH 44195, USA
Abstract
Keywords:
Spindle cell lipoma of the suprasellar region has not been reported in the literature. We report a case of a 4-year-old male with a suprasellar spindle cell lipoma. The patient presented with headaches and visual disturbances. An imaging study revealed a 4 to 5-mm suprasellar mass that was initially thought to be a lipoma or dermoid cyst. Pathologic examination from the partial resection showed a circumscribed lesion consisting of mature adipose tissue with intermixed uniform spindle cells associated with a mucoid matrix, morphologically consistent with a spindle cell lipoma. The spindle cells and vasculature demonstrated focal positivity with CD34 antibody. There was no evidence of lipoblasts, mitoses, necrosis, or osseous tissue. © 2009 Elsevier Inc. All rights reserved. Lipoma; Spindle cell lipoma; Suprasellar region
1. Introduction Lipomas of the central nervous system (CNS) are uncommon lesions, accounting for less than 0.5% of all intracranial tumors. Most intracranial lipomas occur in the midline in the region of the corpus callosum, the ambient cistern, and the suprasellar region. They occur as an adherent extraaxial lesion when located in the sellar region [1]. Less than 40 cases of lipomas occurring in the suprasellar region have been reported in the literature [2]. Approximately half of the lipomas reported in this region have been osteolipomas [3,4]. To our knowledge, a spindle cell variant of a lipoma has not been previously reported in this location. We document a case of spindle cell lipoma presenting in a 4-year-old male. 2. Case report 2.1. Clinical history The patient is a 4-year-old male, who presented with headaches and visual disturbances. A brain magnetic resonance imaging (MRI) study revealed a 4 to 5-mm suprasellar mass that was initially thought to be a lipoma or dermoid cyst (Fig. 1). The patient was observed clinically and radiographically for 5 months. He was scheduled for
⁎ Corresponding author. E-mail address: [email protected] (R.A. Prayson). 1092-9134/$ – see front matter © 2009 Elsevier Inc. All rights reserved. doi:10.1016/j.anndiagpath.2008.12.006
surgical resection after subsequent imaging demonstrated ring enhancement of the mass suggestive of craniopharyngioma, hamartoma, or hypothalamic glioma. At the time of resection, the lesion was described by the surgeon as a globular, pale, rubbery mass adherent to the superior hypothalamus. Approximately 10 months postoperatively, the patient is asymptomatic with no evidence of growth of the residual lesion on imaging studies. 2.2. Pathologic examination Gross examination of the partial resection specimen revealed fragments of tan-white soft tissue. Firm or calcified areas were not identified. Histologic examination on low power showed a circumscribed lesion consisting of mature adipose tissue with intermixed uniform spindle cells associated with a mucoid matrix, morphologically consistent with a spindle cell lipoma (Fig. 2). Areas of necrosis or osseous tissue were not identified. High-power examination failed to show lipoblasts, nuclear atypia, or prominent mitotic activity (Fig. 3). The spindle cells and vasculature demonstrated focal positivity with CD34 antibody (Ventana, Tucson, Ariz; prediluted) (Fig. 4). 3. Discussion The incidence of intracranial lipomas is reported to range from 0.08% to 0.46% of patients at autopsy and 0.06% to 2.6% of patients observed with computed tomography [5-7].
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K.L. Pekarski, R.A. Prayson / Annals of Diagnostic Pathology 13 (2009) 173–175
Fig. 3. An area of monomorphic, bland spindle cell nuclei in a spindle cell lipoma. Fig. 1. Sagittal T1-weighted MRI image demonstrating the hyperintense suprasellar mass.
They account for less than 0.5% of all intracranial tumors and may be seen in association with congenital brain anomalies [2,6]. There appears to be an equal distribution between sexes and across age. The exception is that lipomas of the cerebellopontine angle appear to be twice as common in males. Most intracranial lipomas occur in the midline [2,3]. Most occur in the corpus callosum, the ambient cistern, and the suprasellar/interpeduncular region [4,5,8]. They have a relatively pathognomonic appearance on imaging. On computed tomography, lipomas are homogeneous with a very low attenuation value, nonenhancing with contrast, and sharply demarcated [1,5,7]. On MRI, they are hyperintense on T1-weighted images and hypointense on
T2-weighted images [3,6,7]. Their infiltrative character is best defined by MRI [7]. Lipomas of the CNS grossly appear as dark yellow lesions with deceptively well-demarcated borders. They may be surrounded by a delicate fibrous capsule. The lesions are composed of mature adipocytes that have peripheral, small nuclei, and may contain fibrovascular tissue, bone, and calcification [3,6,9]. A spindle cell lipoma has not previously been described in the suprasellar region. They typically occur in the subcutaneous tissue on the posterior neck, shoulder, and back [10]. Approximately 20% arise in other unusual locations such as the oral cavity, parotid gland, and genital tract. There is a predilection for males, and they are uncommon in children or adolescents. Their clinical behavior is similar to ordinary lipomas, in that they behave in a benign manner. Grossly, they
Fig. 2. Spindle cell lipoma marked by mature adipose tissue with intervening uniform spindle cells.
Fig. 4. Immunostaining CD34 antibody showing focal positive staining of the spindle cells.
K.L. Pekarski, R.A. Prayson / Annals of Diagnostic Pathology 13 (2009) 173–175
also resemble ordinary lipomas with the addition of graywhite gelatinous foci, representing increased cellularity. Their appearance varies microscopically from predominately mature adipose tissue with scattered spindle cells to a predominately spindle cell lesion nearly devoid of adipose. Classically, there is a myxoid stroma with spindle cells arranged in short bundles. The spindle cells are uniform, have a single elongated nucleus, bipolar cytoplasmic processes, and inconspicuous nucleoli and mitoses. The vascular pattern is also inconspicuous. Ropey collagen bundles are characteristic. The spindle cells stain strongly for CD34 and are not immunoreactive for actin, desmin, or S-100 [10]. Less than 40 cases of lipoma occurring in the sellar region have been reported in the literature. Approximately one half of suprasellar lipomas ossify in contrast to intracranial lipomas in other regions that rarely ossify [4]. Most of the lipomas that arise in the sella/pituitary region are asymptomatic and go undetected. Occasional larger size tumors may compress adjacent structures causing symptoms [4,7]. They may also adhere to the floor of the third ventricle, infundibulum, or adjacent cranial nerves producing symptoms [1,3,4]. Fatty lesions and tumors of CNS comprised lipomas, angiolipomas, hibernomas, and primary intracranial liposarcomas [6]. The differential diagnosis would also include lesions that may contain adipose tissue such as dermoid cysts and teratomas [3,4]. The most frequent fatty lesions occurring in the sellar region are lipomas and dermoid cysts [1]. Clinical history in conjunction with imaging studies is vital in narrowing the differential diagnosis. Although the definite origin of lipomas of the CNS has not been established, multiple theories exist. They have been classified as neoplasms by some and as malformations by others [8]. Truwit and Barkovich [2] proposed that they represent a congenital brain malformation rather than a neoplasm or hamartoma [3,4,6]. It is speculated that they result from an abnormal persistence and differentiation of the
175
meninx primitive, which is a derivative of the neural crest. Normally, this tissue is resorbed during embryogenesis and gives rise to subarachnoid cisterns [1-3,5,7]. Some intracranial lipomas have large blood vessels and cranial nerves coursing through them instead of being displaced by them, supporting the idea that they are not neoplasms [4,7]. Lipomatous neoplasms occurring in the suprasellar region are unusual, often representing ordinary lipomas or osteolipomas. They presumably arise from adipocytes that normally reside in the pituitary stalk. Rarely, a spindle cell variant of lipoma may arise in the suprasellar region. References [1] Bonneville F, Cattin F, Marsot-Dupuch K, Dormont D, Bonneville JF, Chiras J. T1 signal hyperintensity in the sellar region: spectrum of findings. Radiographics 2006;26:93-113. [2] Truwit CL, Barkovich AJ. Pathogenesis of intracranial lipoma: an MR study in 42 patients. AJR Am J Roentgenol 1990;155:855-64. [3] Alyaarubi S, Rodd C. Central precocious puberty with and incidental suprasellar lipoma. J Pediatr Endocrinol Metab 2005;18:1027-8. [4] Sinson G, Gennarelli TA, Wells GB. Suprasellar osteolipoma: case report. Surg Neurol 1998;50:457-60. [5] Kikuchi K, Kowada M, Watanabe K. Computed tomography of an intracranial lipoma confined in the suprasellar cistern. Comput Med Imaging Graph 1994;18:187-92. [6] Kleinschmidt-Demasters BK. Lipomas and rare lipomatous tumors. In: McLendon RE, Rosenblum MK, Bigner DD, editors. Russell & Rubinstein's pathology of tumors of the nervous system. 7th ed. New York (NY): Oxford University Press; 2006. p. 599-606. [7] Spallone A, Pitskhelauri DI. Lipomas of the pineal region. Surg Neurol 2004;62:52-9. [8] Hamed LM, Maria BL, Quisling R, Fanous MM, Mickle P. Suprasellar tumors of maldevelopmental origin in Klinefelter's syndrome. A report of two cases. J Clin Neuroophthalmol 1992;12:192-7. [9] Asa SL. Vascular and mesenchymal tumors of the sella turcica. In: Rosai J, Sobin LH, editors. Atlas of tumor pathology. Tumors of the pituitary gland. Washington, DC: Armed Forces Institute of Pathology; 1997. p. 183-5. [10] Benign lipomatous tumors. In: Weiss SW, Goldblum JR, editors. Enzinger & Weiss's soft tissue tumors. 5th ed. Philadelphia: Mosby; 2008. p. 429-76.
Annals of Diagnostic Pathology 13 (2009) 173 – 175
Radiologic-Pathologic Correlation
Suprasellar spindle cell lipoma Krista L. Pekarski, MD, Richard A. Prayson, MD⁎ Cleveland Clinic Foundation, Institute of Pathology, Cleveland, OH 44195, USA
Abstract
Keywords:
Spindle cell lipoma of the suprasellar region has not been reported in the literature. We report a case of a 4-year-old male with a suprasellar spindle cell lipoma. The patient presented with headaches and visual disturbances. An imaging study revealed a 4 to 5-mm suprasellar mass that was initially thought to be a lipoma or dermoid cyst. Pathologic examination from the partial resection showed a circumscribed lesion consisting of mature adipose tissue with intermixed uniform spindle cells associated with a mucoid matrix, morphologically consistent with a spindle cell lipoma. The spindle cells and vasculature demonstrated focal positivity with CD34 antibody. There was no evidence of lipoblasts, mitoses, necrosis, or osseous tissue. © 2009 Elsevier Inc. All rights reserved. Lipoma; Spindle cell lipoma; Suprasellar region
1. Introduction Lipomas of the central nervous system (CNS) are uncommon lesions, accounting for less than 0.5% of all intracranial tumors. Most intracranial lipomas occur in the midline in the region of the corpus callosum, the ambient cistern, and the suprasellar region. They occur as an adherent extraaxial lesion when located in the sellar region [1]. Less than 40 cases of lipomas occurring in the suprasellar region have been reported in the literature [2]. Approximately half of the lipomas reported in this region have been osteolipomas [3,4]. To our knowledge, a spindle cell variant of a lipoma has not been previously reported in this location. We document a case of spindle cell lipoma presenting in a 4-year-old male. 2. Case report 2.1. Clinical history The patient is a 4-year-old male, who presented with headaches and visual disturbances. A brain magnetic resonance imaging (MRI) study revealed a 4 to 5-mm suprasellar mass that was initially thought to be a lipoma or dermoid cyst (Fig. 1). The patient was observed clinically and radiographically for 5 months. He was scheduled for
⁎ Corresponding author. E-mail address: [email protected] (R.A. Prayson). 1092-9134/$ – see front matter © 2009 Elsevier Inc. All rights reserved. doi:10.1016/j.anndiagpath.2008.12.006
surgical resection after subsequent imaging demonstrated ring enhancement of the mass suggestive of craniopharyngioma, hamartoma, or hypothalamic glioma. At the time of resection, the lesion was described by the surgeon as a globular, pale, rubbery mass adherent to the superior hypothalamus. Approximately 10 months postoperatively, the patient is asymptomatic with no evidence of growth of the residual lesion on imaging studies. 2.2. Pathologic examination Gross examination of the partial resection specimen revealed fragments of tan-white soft tissue. Firm or calcified areas were not identified. Histologic examination on low power showed a circumscribed lesion consisting of mature adipose tissue with intermixed uniform spindle cells associated with a mucoid matrix, morphologically consistent with a spindle cell lipoma (Fig. 2). Areas of necrosis or osseous tissue were not identified. High-power examination failed to show lipoblasts, nuclear atypia, or prominent mitotic activity (Fig. 3). The spindle cells and vasculature demonstrated focal positivity with CD34 antibody (Ventana, Tucson, Ariz; prediluted) (Fig. 4). 3. Discussion The incidence of intracranial lipomas is reported to range from 0.08% to 0.46% of patients at autopsy and 0.06% to 2.6% of patients observed with computed tomography [5-7].
174
K.L. Pekarski, R.A. Prayson / Annals of Diagnostic Pathology 13 (2009) 173–175
Fig. 3. An area of monomorphic, bland spindle cell nuclei in a spindle cell lipoma. Fig. 1. Sagittal T1-weighted MRI image demonstrating the hyperintense suprasellar mass.
They account for less than 0.5% of all intracranial tumors and may be seen in association with congenital brain anomalies [2,6]. There appears to be an equal distribution between sexes and across age. The exception is that lipomas of the cerebellopontine angle appear to be twice as common in males. Most intracranial lipomas occur in the midline [2,3]. Most occur in the corpus callosum, the ambient cistern, and the suprasellar/interpeduncular region [4,5,8]. They have a relatively pathognomonic appearance on imaging. On computed tomography, lipomas are homogeneous with a very low attenuation value, nonenhancing with contrast, and sharply demarcated [1,5,7]. On MRI, they are hyperintense on T1-weighted images and hypointense on
T2-weighted images [3,6,7]. Their infiltrative character is best defined by MRI [7]. Lipomas of the CNS grossly appear as dark yellow lesions with deceptively well-demarcated borders. They may be surrounded by a delicate fibrous capsule. The lesions are composed of mature adipocytes that have peripheral, small nuclei, and may contain fibrovascular tissue, bone, and calcification [3,6,9]. A spindle cell lipoma has not previously been described in the suprasellar region. They typically occur in the subcutaneous tissue on the posterior neck, shoulder, and back [10]. Approximately 20% arise in other unusual locations such as the oral cavity, parotid gland, and genital tract. There is a predilection for males, and they are uncommon in children or adolescents. Their clinical behavior is similar to ordinary lipomas, in that they behave in a benign manner. Grossly, they
Fig. 2. Spindle cell lipoma marked by mature adipose tissue with intervening uniform spindle cells.
Fig. 4. Immunostaining CD34 antibody showing focal positive staining of the spindle cells.
K.L. Pekarski, R.A. Prayson / Annals of Diagnostic Pathology 13 (2009) 173–175
also resemble ordinary lipomas with the addition of graywhite gelatinous foci, representing increased cellularity. Their appearance varies microscopically from predominately mature adipose tissue with scattered spindle cells to a predominately spindle cell lesion nearly devoid of adipose. Classically, there is a myxoid stroma with spindle cells arranged in short bundles. The spindle cells are uniform, have a single elongated nucleus, bipolar cytoplasmic processes, and inconspicuous nucleoli and mitoses. The vascular pattern is also inconspicuous. Ropey collagen bundles are characteristic. The spindle cells stain strongly for CD34 and are not immunoreactive for actin, desmin, or S-100 [10]. Less than 40 cases of lipoma occurring in the sellar region have been reported in the literature. Approximately one half of suprasellar lipomas ossify in contrast to intracranial lipomas in other regions that rarely ossify [4]. Most of the lipomas that arise in the sella/pituitary region are asymptomatic and go undetected. Occasional larger size tumors may compress adjacent structures causing symptoms [4,7]. They may also adhere to the floor of the third ventricle, infundibulum, or adjacent cranial nerves producing symptoms [1,3,4]. Fatty lesions and tumors of CNS comprised lipomas, angiolipomas, hibernomas, and primary intracranial liposarcomas [6]. The differential diagnosis would also include lesions that may contain adipose tissue such as dermoid cysts and teratomas [3,4]. The most frequent fatty lesions occurring in the sellar region are lipomas and dermoid cysts [1]. Clinical history in conjunction with imaging studies is vital in narrowing the differential diagnosis. Although the definite origin of lipomas of the CNS has not been established, multiple theories exist. They have been classified as neoplasms by some and as malformations by others [8]. Truwit and Barkovich [2] proposed that they represent a congenital brain malformation rather than a neoplasm or hamartoma [3,4,6]. It is speculated that they result from an abnormal persistence and differentiation of the
175
meninx primitive, which is a derivative of the neural crest. Normally, this tissue is resorbed during embryogenesis and gives rise to subarachnoid cisterns [1-3,5,7]. Some intracranial lipomas have large blood vessels and cranial nerves coursing through them instead of being displaced by them, supporting the idea that they are not neoplasms [4,7]. Lipomatous neoplasms occurring in the suprasellar region are unusual, often representing ordinary lipomas or osteolipomas. They presumably arise from adipocytes that normally reside in the pituitary stalk. Rarely, a spindle cell variant of lipoma may arise in the suprasellar region. References [1] Bonneville F, Cattin F, Marsot-Dupuch K, Dormont D, Bonneville JF, Chiras J. T1 signal hyperintensity in the sellar region: spectrum of findings. Radiographics 2006;26:93-113. [2] Truwit CL, Barkovich AJ. Pathogenesis of intracranial lipoma: an MR study in 42 patients. AJR Am J Roentgenol 1990;155:855-64. [3] Alyaarubi S, Rodd C. Central precocious puberty with and incidental suprasellar lipoma. J Pediatr Endocrinol Metab 2005;18:1027-8. [4] Sinson G, Gennarelli TA, Wells GB. Suprasellar osteolipoma: case report. Surg Neurol 1998;50:457-60. [5] Kikuchi K, Kowada M, Watanabe K. Computed tomography of an intracranial lipoma confined in the suprasellar cistern. Comput Med Imaging Graph 1994;18:187-92. [6] Kleinschmidt-Demasters BK. Lipomas and rare lipomatous tumors. In: McLendon RE, Rosenblum MK, Bigner DD, editors. Russell & Rubinstein's pathology of tumors of the nervous system. 7th ed. New York (NY): Oxford University Press; 2006. p. 599-606. [7] Spallone A, Pitskhelauri DI. Lipomas of the pineal region. Surg Neurol 2004;62:52-9. [8] Hamed LM, Maria BL, Quisling R, Fanous MM, Mickle P. Suprasellar tumors of maldevelopmental origin in Klinefelter's syndrome. A report of two cases. J Clin Neuroophthalmol 1992;12:192-7. [9] Asa SL. Vascular and mesenchymal tumors of the sella turcica. In: Rosai J, Sobin LH, editors. Atlas of tumor pathology. Tumors of the pituitary gland. Washington, DC: Armed Forces Institute of Pathology; 1997. p. 183-5. [10] Benign lipomatous tumors. In: Weiss SW, Goldblum JR, editors. Enzinger & Weiss's soft tissue tumors. 5th ed. Philadelphia: Mosby; 2008. p. 429-76.