- Email: [email protected]
Incidental meningioma in the adrenal gland: report of a case
520
CORRESPONDENCE
Pathology (2007), 39(5), October
Incidental meningioma in the adrenal gland: report of a case Sir, Meningiomas are tumours of arachnoidal cap cell origin, predominantly arising within the central nervous system (CNS) and constituting between 13 and 26% of primary intracranial tumours.1 Extra-axial meningiomas are well recognised, most of which occur within the head and neck. Meningiomas arising in extracranial and extraspinal locations outside of the head and neck region are uncommon and have been reported in a variety of sites including skin, soft tissue, lungs, mediastinum and retroperitoneum.2–7 Their reported histological appearances and immunohistochemical profile are similar to those of meningiomas of the CNS.2 Most cases exhibit benign behaviour, although rare examples of malignant meningiomas arising in the scalp, retroperitoneum and lung have been described.6,7 We describe a case of a small meningioma in the adrenal cortex discovered as an incidental finding during routine histological examination of a nephrectomy and adrenalectomy specimen performed for renal cell carcinoma. A review
CORRESPONDENCE
Fig. 1 Macroscopic view of small adrenal cortical nodule with a uniform white cut surface.
of the English literature reveals that meningioma has not been previously described in this site. A 67-year-old woman presented to her general practitioner with symptoms of urinary frequency. The patient had a medical history of type 2 diabetes mellitus, no history of meningioma and no relevant family history. Ultrasound scan of the pelvis and abdomen revealed a large cystic mass in the pelvis corresponding to the site of the right ovary, and a 4 cm left renal mass. Computed tomography (CT) scan revealed a 5 cm solid enhancing lesion with a central low-density non-enhancing area located in the middle third of the left kidney. No lesions were noted in either adrenal gland. The patient proceeded to excision of the pelvic mass, the pathology of which was a right ovarian benign serous cystadenoma, followed shortly afterwards by a laparoscopic nephrectomy and adrenalectomy. Her immediate postoperative course was uncomplicated, and at follow-up at 6 months there was no evidence of recurrence. Although a cerebral CT scan was not performed, she had no clinical evidence of an intracranial lesion. Macroscopically, the adrenal gland contained a 3 mm firm, white nodule within the cortex (Fig. 1). The kidney contained a 40 mm tumour within the upper pole and middle zone of the kidney with a heterogeneous pale tan, yellow and cream cut surface, bounded by the renal capsule. Microscopic examination revealed that the adrenal tumour was well circumscribed but unencapsulated, composed of whorls of spindled and epithelioid cells with bland oval nuclei. Small nucleoli and occasional intranuclear cytoplasmic inclusions were noted, and a single psammoma body was present. Numerous small, thin-walled vessels were present within the nodule. No mitoses were seen (Fig. 2). Immunohistochemical staining for vimentin and epithelial membrane antigen (EMA; Fig. 2 inset) were strongly positive, with focal positivity for AE1/AE3 and progesterone receptor. The tumour cells were negative for S-100, CAM5.2, oestrogen receptor, CD34, desmin, chromogranin A and inhibin-alpha. The renal tumour was a clear cell renal cell carcinoma, Fuhrman grade 3, involving the wall of the renal vein although confined by the renal capsule. Electron microscopy of the adrenal nodule demonstrated cells with complex interlocking broad processes forming a
521
Fig. 2 High magnification showing a whorled arrangement of bland spindled and epithelioid cells with intranuclear pseudoinclusions (H&E, 6400). Inset: positive EMA (6400).
‘jigsaw puzzle’-like pattern (Fig. 3), as well as parallel layers of more slender cells with elongated bipolar processes. The cells were in close apposition with one another, joined by numerous desmosomes (Fig. 3 inset), with occasional desmosome-like and more rudimentary intercellular junctions. There was no external lamina. Nuclei showed a smooth surface contour with occasional pseudo-inclusions. Intermediate filaments occupied much of the cytoplasm but organelles were rather sparse. No neuroendocrine granules, melanosomes, other secretion products or pinocytotic vesicles were identified. The combination of histological, immunohistochemical and ultrastructural findings were considered characteristic of a meningioma. As there was no known primary tumour it was considered to be a primary ectopic meningioma arising in the adrenal cortex. Most meningiomas arise within the cranial cavity and are dural based, and within the spine most arise in the thoracic region.1 Meningiomas arising outside the central neuraxis
Fig. 3 Electron micrograph illustrating complex interdigitating cell processes. The cytoplasm contains numerous intermediate filaments, scattered mitochondria and free ribosomes (bar55 mm). Inset: multiple desmosomes and a few rudimentary intercellular junctions (bar51 mm).
522
CORRESPONDENCE
are ectopic, and are termed primary if they do not originate from the CNS.5 Secondary meningiomas are either due to direct extension or are metastases from CNS tumours, with lungs, lymph nodes and liver the most common sites for metastasis.6,8 Over 70% of metastatic meningiomas occur in patients who have previously undergone craniotomies.8 Most extra-axial meningiomas are found within the head and neck and have been described in the orbit, skull bones, middle ear, nasal cavity, paranasal sinuses, parotid, neck and base of the skull as well as in the facial and paravertebral skin.4,5 The pathogenesis of extracranial and extraspinal meningiomas outside of the head and neck region (excluding direct extension and metastasis) is poorly understood, and at present remains speculative. Theories include origin from arachnoid cells within the sheaths of cranial nerves,3,5,9,10 and from embryonic nests of arachnoid cells with no connection to cranial nerves.3,8,10 Origin of pulmonary meningiomas from minute pulmonary meningothelial-like nodules (MPMN) has been proposed,4,11 but seems unlikely as these nodules are common (estimated at 1/100 autopsies), almost always multiple, and genotypical studies have supported their reactive nature.11 Other authors have suggested ‘metaplasia’ of Schwann cells,4 fibroblasts which ‘differentiate’ into arachnoid cells,5,6,10 and origin from pleuripotent mesenchymal cells.4 Origin from perineurial cells, which are functionally and anatomically continuous with the arachnoid, has also been proposed.5,7 A recent case report of a mesenteric ‘meningiomatous perineurial tumour’ comments on the morphological and immunohistochemical overlap between meningioma and perineurioma, the structural and functional similarities between the meninges and peripheral nerve sheath, and their shared cytogenetic alterations of chromosome 22.12 Although both tumours show EMA positivity, perineurioma has characteristic ultrastructural features including at least partial encirclement of the cells by basement membrane, frequent pinocytotic vesicles and lack of desmosomes, features not seen in meningioma1 or the present case, allowing them to be distinguished.5 The differential diagnosis of a spindle cell nodule within the adrenal cortex includes benign peripheral nerve sheath tumours, in particular schwannomas, which are characteristically S-100 positive and ultrastructurally show a continuous external lamina that coats each individual cell process. Intercellular junctions are sparse, rudimentary and not of desmosome type. Adrenal neurofibroma, and malignant peripheral nerve sheath tumours have also been described at this site. Primary adenomatoid tumour, although rare, is a differential diagnosis macroscopically with a characteristic homogenous white appearance. Microscopically, however, it is distinct with a ‘sieve-like’ appearance formed by gland-like spaces, and tumour cell expression of calretinin and AE1/AE3 keratin. Ovarian thecal metaplasia, leiomyoma, haemangioma and solitary fibrous tumours are also considerations, however, these can be distinguished by their characteristic morphological, immunohistochemical and ultrastructural features.13 In summary, we present a case of an incidental primary meningioma of the adrenal gland, a location that has not previously been reported. Although not usually a consideration in the adrenal cortex, meningiomas can now be considered in the differential diagnosis of spindle cell lesions at this site.
Pathology (2007), 39(5), October
Caroline L. Cooper* Edward J. Wills{ Nader Awad{ Richard Jaworski§ *Department of Anatomical Pathology, Royal Prince Alfred Hospital, Camperdown, {Electron Microscope Unit, Department of Anatomical Pathology, Concord Repatriation General Hospital, Concord, {Department of Urology, Port Macquarie Base Hospital, Port Macquarie, and §Symbion Health–Laverty Pathology, North Ryde, New South Wales, Australia Contact Dr R. Jaworski. E-mail: [email protected] 1. Louis DN, Scheithauer BW, Budka H, von Deimling A, Kepes JJ. Meningiomas. In: Kleihues P, Cavenee WK, editors. World Health Organisation Classification of Tumours. Pathology and Genetics of Tumours of the Nervous System. Lyon: IARC, 2000; 176–84. 2. Burger PC, Scheithauer BW. Tumours of meningothelial cells. In: Burger PC, Scheithauer BW, editors. Atlas of Tumour Pathology: Tumours of the Central Nervous System. 3rd Series, Fascicle 10, Washington DC: Armed Forces Institute of Pathology, 1994; 259–86. 3. Lopez DA, Silvers DN, Helwig EB. Cutaneous meningiomas – a clinicopathologic study. Cancer 1974; 34: 728–44. 4. Kaleem Z, Fitzpatrick MM, Ritter JH. Primary pulmonary meningioma: Report of a case and review of the literature. Arch Pathol Lab Med 1997; 121: 631–6. 5. Tomaru U, Hasegawa T, Hasegawa F, Kito M, Hirose T, Shimoda T. Primary extracranial meningioma of the foot: A case report. Jpn J Clin Oncol 2000; 30: 313–7. 6. Prayson RA, Farver CF. Primary pulmonary malignant meningioma. Am J Surg Pathol 1999; 23: 722–6. 7. Huszar M, Fanburg JC, Dickersin GR, Kirshner JJ, Rosenberg AE. Retroperitoneal malignant meningioma: A light microscopic, immunohistochemical and ultrastructural study. Am J Surg Pathol 1996; 20: 492–9. 8. Celli P, Palma L, Domenicucci M, Scarpinati M. Histologically benign recurrent meningioma metastasising to the parotid gland: Case report and review of the literature. Neurosurgery 1992; 31: 1113–6. 9. Hoye SJ, Hoar CS, Murray JE. Extracranial meningioma presenting as a tumor of the neck. Am J Surg 1960; 100: 486–9. 10. Kemnitz P, Spormann H, Heinrich P. Meningioma of lung: First report with light and electron microscopic findings. Ultrastruct Pathol 1982; 3: 359–65. 11. Ionescu DN, Sasatomi E, Aldeeb D, et al. Pulmonary meningotheliallike nodules: A genotypic comparison with meningiomas. Am J Surg Pathol 2004; 28: 207–14. 12. Castellvi J, Lloreta J, Huguet P, Plaza JA, Ramon y Cajal S. A meningiomatous perineurial tumour located in the mesentery. An ultrastructural and immunohistochemical study. Histopathology 2005; 48: 311–2. 13. Lack EE. Other neoplasms and tumour-like lesions of the adrenal glands. In: Lack EE, editor. Atlas of Tumour Pathology: Tumours of the Adrenal Gland and Extra-Adrenal Paraganglia. 3rd Series, Fascicle 19, Washington DC: Armed Forces Institute of Pathology, 1995; 169–98.
DOI: 10.1080/00313020701570020
CORRESPONDENCE
Pathology (2007), 39(5), October
Incidental meningioma in the adrenal gland: report of a case Sir, Meningiomas are tumours of arachnoidal cap cell origin, predominantly arising within the central nervous system (CNS) and constituting between 13 and 26% of primary intracranial tumours.1 Extra-axial meningiomas are well recognised, most of which occur within the head and neck. Meningiomas arising in extracranial and extraspinal locations outside of the head and neck region are uncommon and have been reported in a variety of sites including skin, soft tissue, lungs, mediastinum and retroperitoneum.2–7 Their reported histological appearances and immunohistochemical profile are similar to those of meningiomas of the CNS.2 Most cases exhibit benign behaviour, although rare examples of malignant meningiomas arising in the scalp, retroperitoneum and lung have been described.6,7 We describe a case of a small meningioma in the adrenal cortex discovered as an incidental finding during routine histological examination of a nephrectomy and adrenalectomy specimen performed for renal cell carcinoma. A review
CORRESPONDENCE
Fig. 1 Macroscopic view of small adrenal cortical nodule with a uniform white cut surface.
of the English literature reveals that meningioma has not been previously described in this site. A 67-year-old woman presented to her general practitioner with symptoms of urinary frequency. The patient had a medical history of type 2 diabetes mellitus, no history of meningioma and no relevant family history. Ultrasound scan of the pelvis and abdomen revealed a large cystic mass in the pelvis corresponding to the site of the right ovary, and a 4 cm left renal mass. Computed tomography (CT) scan revealed a 5 cm solid enhancing lesion with a central low-density non-enhancing area located in the middle third of the left kidney. No lesions were noted in either adrenal gland. The patient proceeded to excision of the pelvic mass, the pathology of which was a right ovarian benign serous cystadenoma, followed shortly afterwards by a laparoscopic nephrectomy and adrenalectomy. Her immediate postoperative course was uncomplicated, and at follow-up at 6 months there was no evidence of recurrence. Although a cerebral CT scan was not performed, she had no clinical evidence of an intracranial lesion. Macroscopically, the adrenal gland contained a 3 mm firm, white nodule within the cortex (Fig. 1). The kidney contained a 40 mm tumour within the upper pole and middle zone of the kidney with a heterogeneous pale tan, yellow and cream cut surface, bounded by the renal capsule. Microscopic examination revealed that the adrenal tumour was well circumscribed but unencapsulated, composed of whorls of spindled and epithelioid cells with bland oval nuclei. Small nucleoli and occasional intranuclear cytoplasmic inclusions were noted, and a single psammoma body was present. Numerous small, thin-walled vessels were present within the nodule. No mitoses were seen (Fig. 2). Immunohistochemical staining for vimentin and epithelial membrane antigen (EMA; Fig. 2 inset) were strongly positive, with focal positivity for AE1/AE3 and progesterone receptor. The tumour cells were negative for S-100, CAM5.2, oestrogen receptor, CD34, desmin, chromogranin A and inhibin-alpha. The renal tumour was a clear cell renal cell carcinoma, Fuhrman grade 3, involving the wall of the renal vein although confined by the renal capsule. Electron microscopy of the adrenal nodule demonstrated cells with complex interlocking broad processes forming a
521
Fig. 2 High magnification showing a whorled arrangement of bland spindled and epithelioid cells with intranuclear pseudoinclusions (H&E, 6400). Inset: positive EMA (6400).
‘jigsaw puzzle’-like pattern (Fig. 3), as well as parallel layers of more slender cells with elongated bipolar processes. The cells were in close apposition with one another, joined by numerous desmosomes (Fig. 3 inset), with occasional desmosome-like and more rudimentary intercellular junctions. There was no external lamina. Nuclei showed a smooth surface contour with occasional pseudo-inclusions. Intermediate filaments occupied much of the cytoplasm but organelles were rather sparse. No neuroendocrine granules, melanosomes, other secretion products or pinocytotic vesicles were identified. The combination of histological, immunohistochemical and ultrastructural findings were considered characteristic of a meningioma. As there was no known primary tumour it was considered to be a primary ectopic meningioma arising in the adrenal cortex. Most meningiomas arise within the cranial cavity and are dural based, and within the spine most arise in the thoracic region.1 Meningiomas arising outside the central neuraxis
Fig. 3 Electron micrograph illustrating complex interdigitating cell processes. The cytoplasm contains numerous intermediate filaments, scattered mitochondria and free ribosomes (bar55 mm). Inset: multiple desmosomes and a few rudimentary intercellular junctions (bar51 mm).
522
CORRESPONDENCE
are ectopic, and are termed primary if they do not originate from the CNS.5 Secondary meningiomas are either due to direct extension or are metastases from CNS tumours, with lungs, lymph nodes and liver the most common sites for metastasis.6,8 Over 70% of metastatic meningiomas occur in patients who have previously undergone craniotomies.8 Most extra-axial meningiomas are found within the head and neck and have been described in the orbit, skull bones, middle ear, nasal cavity, paranasal sinuses, parotid, neck and base of the skull as well as in the facial and paravertebral skin.4,5 The pathogenesis of extracranial and extraspinal meningiomas outside of the head and neck region (excluding direct extension and metastasis) is poorly understood, and at present remains speculative. Theories include origin from arachnoid cells within the sheaths of cranial nerves,3,5,9,10 and from embryonic nests of arachnoid cells with no connection to cranial nerves.3,8,10 Origin of pulmonary meningiomas from minute pulmonary meningothelial-like nodules (MPMN) has been proposed,4,11 but seems unlikely as these nodules are common (estimated at 1/100 autopsies), almost always multiple, and genotypical studies have supported their reactive nature.11 Other authors have suggested ‘metaplasia’ of Schwann cells,4 fibroblasts which ‘differentiate’ into arachnoid cells,5,6,10 and origin from pleuripotent mesenchymal cells.4 Origin from perineurial cells, which are functionally and anatomically continuous with the arachnoid, has also been proposed.5,7 A recent case report of a mesenteric ‘meningiomatous perineurial tumour’ comments on the morphological and immunohistochemical overlap between meningioma and perineurioma, the structural and functional similarities between the meninges and peripheral nerve sheath, and their shared cytogenetic alterations of chromosome 22.12 Although both tumours show EMA positivity, perineurioma has characteristic ultrastructural features including at least partial encirclement of the cells by basement membrane, frequent pinocytotic vesicles and lack of desmosomes, features not seen in meningioma1 or the present case, allowing them to be distinguished.5 The differential diagnosis of a spindle cell nodule within the adrenal cortex includes benign peripheral nerve sheath tumours, in particular schwannomas, which are characteristically S-100 positive and ultrastructurally show a continuous external lamina that coats each individual cell process. Intercellular junctions are sparse, rudimentary and not of desmosome type. Adrenal neurofibroma, and malignant peripheral nerve sheath tumours have also been described at this site. Primary adenomatoid tumour, although rare, is a differential diagnosis macroscopically with a characteristic homogenous white appearance. Microscopically, however, it is distinct with a ‘sieve-like’ appearance formed by gland-like spaces, and tumour cell expression of calretinin and AE1/AE3 keratin. Ovarian thecal metaplasia, leiomyoma, haemangioma and solitary fibrous tumours are also considerations, however, these can be distinguished by their characteristic morphological, immunohistochemical and ultrastructural features.13 In summary, we present a case of an incidental primary meningioma of the adrenal gland, a location that has not previously been reported. Although not usually a consideration in the adrenal cortex, meningiomas can now be considered in the differential diagnosis of spindle cell lesions at this site.
Pathology (2007), 39(5), October
Caroline L. Cooper* Edward J. Wills{ Nader Awad{ Richard Jaworski§ *Department of Anatomical Pathology, Royal Prince Alfred Hospital, Camperdown, {Electron Microscope Unit, Department of Anatomical Pathology, Concord Repatriation General Hospital, Concord, {Department of Urology, Port Macquarie Base Hospital, Port Macquarie, and §Symbion Health–Laverty Pathology, North Ryde, New South Wales, Australia Contact Dr R. Jaworski. E-mail: [email protected] 1. Louis DN, Scheithauer BW, Budka H, von Deimling A, Kepes JJ. Meningiomas. In: Kleihues P, Cavenee WK, editors. World Health Organisation Classification of Tumours. Pathology and Genetics of Tumours of the Nervous System. Lyon: IARC, 2000; 176–84. 2. Burger PC, Scheithauer BW. Tumours of meningothelial cells. In: Burger PC, Scheithauer BW, editors. Atlas of Tumour Pathology: Tumours of the Central Nervous System. 3rd Series, Fascicle 10, Washington DC: Armed Forces Institute of Pathology, 1994; 259–86. 3. Lopez DA, Silvers DN, Helwig EB. Cutaneous meningiomas – a clinicopathologic study. Cancer 1974; 34: 728–44. 4. Kaleem Z, Fitzpatrick MM, Ritter JH. Primary pulmonary meningioma: Report of a case and review of the literature. Arch Pathol Lab Med 1997; 121: 631–6. 5. Tomaru U, Hasegawa T, Hasegawa F, Kito M, Hirose T, Shimoda T. Primary extracranial meningioma of the foot: A case report. Jpn J Clin Oncol 2000; 30: 313–7. 6. Prayson RA, Farver CF. Primary pulmonary malignant meningioma. Am J Surg Pathol 1999; 23: 722–6. 7. Huszar M, Fanburg JC, Dickersin GR, Kirshner JJ, Rosenberg AE. Retroperitoneal malignant meningioma: A light microscopic, immunohistochemical and ultrastructural study. Am J Surg Pathol 1996; 20: 492–9. 8. Celli P, Palma L, Domenicucci M, Scarpinati M. Histologically benign recurrent meningioma metastasising to the parotid gland: Case report and review of the literature. Neurosurgery 1992; 31: 1113–6. 9. Hoye SJ, Hoar CS, Murray JE. Extracranial meningioma presenting as a tumor of the neck. Am J Surg 1960; 100: 486–9. 10. Kemnitz P, Spormann H, Heinrich P. Meningioma of lung: First report with light and electron microscopic findings. Ultrastruct Pathol 1982; 3: 359–65. 11. Ionescu DN, Sasatomi E, Aldeeb D, et al. Pulmonary meningotheliallike nodules: A genotypic comparison with meningiomas. Am J Surg Pathol 2004; 28: 207–14. 12. Castellvi J, Lloreta J, Huguet P, Plaza JA, Ramon y Cajal S. A meningiomatous perineurial tumour located in the mesentery. An ultrastructural and immunohistochemical study. Histopathology 2005; 48: 311–2. 13. Lack EE. Other neoplasms and tumour-like lesions of the adrenal glands. In: Lack EE, editor. Atlas of Tumour Pathology: Tumours of the Adrenal Gland and Extra-Adrenal Paraganglia. 3rd Series, Fascicle 19, Washington DC: Armed Forces Institute of Pathology, 1995; 169–98.
DOI: 10.1080/00313020701570020