Melanotic Schwannoma of Adrenal Gland - A Rare Entity/ Diagnostic Dilemma

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Melanotic schwannoma of adrenal gland is very rare entity with only two series and less than 100 cases reported in literature. We report a case of melanotic schwannoma.

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Melanotic Schwannoma of Adrenal Gland - A Rare Entity/ Diagnostic Dilemma

  1. 1. Melanotic Schwannoma of Adrenal Gland - A Rare Entity/ Diagnostic Dilemma
  2. 2. a p o l l o m e d i c i n e 1 0 ( 2 0 1 3 ) 7 7 e8 1 Available online at www.sciencedirect.com journal homepage: www.elsevier.com/locate/apme Case Report Melanotic schwannoma of adrenal gland e A rare entity/ diagnostic dilemma Feroz Amir Zafar a, Ishfaque A. Geelani a, Pravin Govardhane a, H. Girish a, D.V.S.L.N. Sharma a, V. Rajagopal a,*, Meenakshi Swain b, G. Swarnalatha b a b Department of Urology, Apollo Hospitals, Hyderabad, India Department of Histopathology, Apollo Hospitals, Hyderabad, India article info abstract Article history: Introduction and objective: Melanotic schwannoma of adrenal gland is very rare entity with Received 31 January 2013 only two series and less than 100 cases reported in literature. We report a case of melanotic Accepted 2 February 2013 schwannoma. Available online 9 February 2013 Case report: A 62 years old man, a resident of Tanzania presented with 6 months history of lower urinary tract symptoms (LUTS) for which he was evaluated and a right adrenal mass Keywords: Melanotic schwannoma detected incidentally on ultrasound. He is known case of hypertension and hypothyroidism for which he is taking regular Melanoma medications. On general examination pulse was 80/min, regular and BP was130/80 mm of Nerve sheath tumor Hg. Abdominal examination was unremarkable. MDCT examination revealed a right ad- Adrenal schwannoma renal mass (4 Â 4.8 cm) showing mild enhancement post contrast study with central area of relatively less enhancement showing no significant contrast washout on delayed study. The provisional diagnosis was ? pheochromocytoma, ? malignant. Functional study was found to be normal. Laparoscopic exploration was done and mass excised. Gross pathological examination showed a single globular circumscribed soft tissue mass measuring 4.5 Â 4 Â 3 cm and weighing 50 g with a nodular surface. The cut surface was black with a central golden brown area measuring around 2.2 Â 1.8 cm. A diagnosis of malignant melanoma was considered, however in view of circumscription bland nuclei, absent of nucleoli, very few mitoses and presence of nerve fascicles; a diagnosis of melanotic schwannoma was favored. The patient was advised regular follow-up. Conclusion: Melanotic schwannoma of adrenal is a very rare entity and every effort should be made to rule out melanoma. Copyright ª 2013, Indraprastha Medical Corporation Ltd. All rights reserved. 1. Introduction Melanotic schwannoma of the adrenals is a rare, accounting for only 1e3% of all schwannomas and only 1% of all retroperitoneal tumors.1,2 They are circumscribed but unencapsulated, grossly pigmented tumor, composed of cells having the ultra structure and immunophenotype of Schwann cells that contain melanosomes and are reactive for * Corresponding author. E-mail address: raja_urol@rediffmail.com (V. Rajagopal). 0976-0016/$ e see front matter Copyright ª 2013, Indraprastha Medical Corporation Ltd. All rights reserved. http://dx.doi.org/10.1016/j.apme.2013.02.001
  3. 3. 78 a p o l l o m e d i c i n e 1 0 ( 2 0 1 3 ) 7 7 e8 1 Fig. 1 e CECT of abdomen & pelvis (coronal, saggital & transverse planes) showing the right adrenal mass (white arrow). Fig. 3 e CECT of abdomen & pelvis (coronal, saggital & transverse planes) showing the right adrenal mass (white arrow). melanoma markers. Cytological atypia is not uncommon. The vast majority of non-psammomatous tumors affect spinal nerves and paraspinal ganglia, whereas the psammomatous lesions also involve autonomic nerves of viscera, such as the intestinal tract, adrenal and heart. About 50% of patients with psammomatous melanotic schwannoma have the rare inherited autosomal-dominant disorder Carney complex type Fig. 2 e CECT of abdomen & pelvis (coronal, saggital & transverse planes) showing the right adrenal mass (white arrow). Fig. 4 e Laparoscopic views of the darkly pigmented tumor (yellow arrow).
  4. 4. a p o l l o m e d i c i n e 1 0 ( 2 0 1 3 ) 7 7 e8 1 Fig. 5 e Laparoscopic views of the darkly pigmented tumor (yellow arrow). I (CNC) characterized by facial pigmentation, Cardiac myxoma, and endocrine overactivity. A correct preoperative diagnosis is difficult to make and these tumors are often misdiagnosed as other soft tissue lesions occurring in the retroperitoneum. Over 80 cases of one or more tumors have been reported in literature so far.3 We describe a case of melanotic schwannoma of the adrenal gland. 2. Case presentation Sixty two years gentleman, resident of Tanzania presented with h/o lower urinary tract symptoms (LUTS) since >6 months and an incidentally detected right adrenal mass. He gave a past history of hypertension and hypothyroidism Fig. 6 e Resected specimen (pigmented). 79 Fig. 7 e Cut section of the tumor (heterogeneous). which was under control with medications. On clinical examination, pulse e 80/min, BP e 130/80 mm of Hg. General examination e No pallor/icterus/cyanosis/clubbing/edema feet. P/A e soft, non-tender, no mass was palpable. Investigations revealed Hb-12 g%, TLC-4100/mm,3 S. creatinine e 1.2 mg%, RBS e 74 mg%, Metanephrines (24 h urine) e 1.0 mg/day, VMA (24 h urine) e 8.7/day, S. cortisol (dexamethasone suppression test) e 0.56 mg/dl. CT scan (Figs. 1e3) showed a right adrenal mass (4 Â 4.8 cm) showing mild enhancement post contrast study with central area of relatively less enhancement showing no significant contrast wash out on delayed study (? pheochromocytoma/? malignant). At Laparoscopic exploration, a heterogeneous, darkly pigmented (almost black) unencapsulated neoplasm was found in the right retroperitoneal space, medially displacing the inferior vena cava and clearly separated from the kidney and the renal vein, which are pushed downward. The tumor was completely excised (Figs. 4 and 5). The specimen was sent for histopathological examination. Fig. 8 e Low power 103 H&E stain.
  5. 5. 80 a p o l l o m e d i c i n e 1 0 ( 2 0 1 3 ) 7 7 e8 1 Fig. 9 e 203 showing tumor attached to nerve fascicles. Fig. 11 e Immunohistochemistry showing positive S 100. 2.1. Gross description Single globular circumscribed soft tissue measuring 4.5 Â 4 Â 3 cm & weighing 50 g. External surface was nodular (Fig. 6). Cut surface was black with a central golden brown area measuring around 2.2 Â 1.8 cm (Fig. 7). 2.2. Microscopically Lobules and nests of tumor cells with large areas of necrosis and hemorrhage. The tumor cells are spindle shaped and arranged in intersecting fascicles. Tumor cells have moderate ill defined fibrillary cytoplasm and have elongated bland vesicular nuclei with few showing nuclear grooves (Fig. 8). Abundant brownish black pigment is seen with in tumor cells and also within the histiocytes (Fig. 10). Few mitoses were seen averaging 1e2/10 hpf. Prominent nuclei typical of melanoma are not seen. Perl’s stain is positive in the pigment in hemosiderin laden macrophages and negative in pigment in tumor cells (Fig. 11). A few nerve fascicles are seen at the periphery adherent to the tumor (Fig. 9). 3. Melanotic schwannomas (MS) were first described in 1932 by Millar.4 These tumors are rare, with approximately 80 cases reported in the literature to date.3 Melanotic schwannomas are of neural crest origin probably caused by the neoplastic proliferation of a common precursor cell for both Schwann cells and melanocytes.5,6 Schwannoma is a neurogenic tumor usually arising between the third and sixth decades of life, with an equal predilection for men and women. It may occur in any organ or nerve trunk with the exception of cranial nerves I and II, which lack Schwann cells A preoperative diagnosis is very difficult to make because of the lack of typical imaging features (US, CT and MRI) that distinguish schwannomas from retroperitoneal malignancies.7 Even with accurate preoperative imaging and intraoperative frozen section analysis, the presence of a possible malignancy cannot be excluded, so a definitive diagnosis can be obtained only through careful histological and immunohistochemical examination. Surgical excision is considered the treatment of choice for these tumors, which respond poorly to radiation and chemotherapy.8 We were unable to make a correct preoperative diagnosis. The following differential diagnosis was considered: malignant melanoma, melanotic schwannoma, pigmented pheochromocytoma and leiomyosarcoma. There was a diagnostic dilemma and malignant melanoma was strongly considered, however in a view of the circumscription, bland nuclei, absence of nucleoli, very few mitoses and the presence of nerve fascicles, a diagnosis of a melanotic schwannoma was finally favored. 4. Fig. 10 e H&E (403) e Spindle cells running in fascicles with intracytoplasmic melanin pigment. Discussion Conclusion Melanotic schwannoma is a rare variant of schwannoma composed of melanin-producing cells with ultrastructural features of Schwann cells. Distinguishing between this tumor and malignant melanoma is important in planning management. Total resection should be performed. Appropriate longterm follow-up is needed for all melanotic schwannomas.
  6. 6. a p o l l o m e d i c i n e 1 0 ( 2 0 1 3 ) 7 7 e8 1 Conflicts of interest 4. All authors have none to declare. references 5. 6. 1. Ueda M, Okamoto Y, Ueki M. A pelvic retroperitoneal schwannoma arising in the right paracolpium. Gynecol Oncol. 1996;60:480e483. 2. Hayasaka K, Tanaka Y, Soeda S, Huppert P, Claussen CD. MR findings in primary retroperitoneal schwannoma. Acta Radiol. 1999;40:78e82. 3. Zhang HY, Yang GH, Chen HJ, et al. Clinicopathological, immunohistochemical, and ultrastructural study of 13 cases of 7. 8. 81 melanotic schwannoma. Chin Med J (Engl). 2005;118(17):1451e1461. Millar W. Malignant melanotic tumor of the ganglion cells arising from the thoracic sympathetic ganglion. J Pathol. 1932;35:351e357. Vallat-Decouvelaere A-V, Wassef M, Lot G, et al. Spinal melanotic schwannoma: a tumour with poor prognosis. Histopathology. 1999;35:558e566. Watson JC, Stratakis CA, Bryant-Greenwood PK, et al. Neurosurgical implications of Carney complex. J Neurosurg. 2000;92:413e418. Hughes MJ, Thomas JM, Fisher C, Moskovic EC. Imaging features of retroperitoneal and pelvic schwannomas. Clin Radiol. 2005;60:886e893. Daneshmand S, Youssefzadeh D, Chamie K, et al. Benign retroperitoneal schwannoma: a case series and review of the literature. Urology. 2003;62:993e997.
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