|Year : 2019 | Volume
| Issue : 1 | Page : 147-151
Case report of vulvar schwannoma and literature review
RA Vhriterhire1, TZ Swende2, EP Onche2, N Terhemba1
1 Department of Anatomical Pathology, College of Health Sciences, Benue State University, Makurdi, North-Central, Nigeria
2 Department of Obstetrics and Gynaecology, College of Health Sciences, Benue State University, Makurdi, North-Central, Nigeria
|Date of Web Publication||17-Apr-2019|
Dr. R A Vhriterhire
Department of Anatomical Pathology, College of Health Sciences, Benue State University, Makurdi
Source of Support: None, Conflict of Interest: None
Schwannoma is a rare benign encapsulated tumor derived from neural sheath cells. The tumor is more common in the head and neck regions and the extremities. Its location in the vulvovaginal region is a rare phenomenon with a few reported cases worldwide. We report a case of a large vulvar schwannoma occurring in an 18-year-old woman, primigravidae at 35 weeks gestation. The ulcerated tumor mass which measured 10.5 × 7 × 6.5 cm and weighed 249.2 grams was located on the right labium majus with extension into the vagina. The tumor evoked strong immunohistochemical reactivity to S-100. There was no evidence of recurrence after several weeks of excision of the neoplasm.
Keywords: Pelvic nerve sheath tumor; schwannoma; vulva mass.
|How to cite this article:|
Vhriterhire R A, Swende T Z, Onche E P, Terhemba N. Case report of vulvar schwannoma and literature review. Trop J Obstet Gynaecol 2019;36:147-51
|How to cite this URL:|
Vhriterhire R A, Swende T Z, Onche E P, Terhemba N. Case report of vulvar schwannoma and literature review. Trop J Obstet Gynaecol [serial online] 2019 [cited 2020 Feb 17];36:147-51. Available from: http://www.tjogonline.com/text.asp?2019/36/1/147/256473
| Introduction|| |
Schwannoma, also known as neurilemoma or neurinoma, is a benign encapsulated tumor of proliferating differentiated Schwann cells of nerve sheaths. This tumor is most common between the fourth to the sixth decade. There is an equal gender occurrence of schwannomas.
The tumor has a peculiar characteristic of predilection for the head and neck regions and the flexor surfaces of upper and lower limbs. Situation in deep regions such as the retroperitoneum and the mediastinium has been recorded in the literature. The growth of this tumor in the vulva or vagina is rare and only a number of cases have been observed. The tumor is usually small in size in most locations except in the mediastinum and retroperitonium. We report below a case of a large schwannoma involving the vulva in an 18-year-old woman.
| Case Report|| |
An unbooked 18-year-old, primigravidae Nigerian woman, presented with a large ulcerated bleeding mass of long-standing duration attached mainly to the right labium majus.
The tumor had been present for several months and slowly increased in size. She had previously sought surgical intervention in a rural hospital 2 weeks prior to presentation. There was a markedly accelerated growth of the swelling after the surgical intervention with subsequent enlargement and descent of the mass beyond the vulva, bleeding and pain, features not previously present before the intervention.
She was at 35 weeks' gestation and referred from the rural hospital on account of the accelerated growth of the vulvovaginal lump and uncontrollable hemorrhage. The lump had been noticed 2 years prior to presentation, initially asymptomatic and slowly increasing in size. However, 3 weeks prior to surgical intervention at the rural hospital, she had developed paraesthesia in the inner aspect of the right thigh and subsequently started limping with the right lower limb. She was markedly pale, dehydrated, and was in shock with a pulse rate of 142 beats per minute, a thready small volume pulse, and blood pressure of 80/40 mmHg. There was a well - circumscribed but ulcerated gray mass, measuring 10 cm by 8 cm protruding through an incision in the right labium majus and also involving the right vaginal wall. Her urgent packed cell volume was 20%; her blood group was O+ and serum electrolytes were essentially within normal reference ranges except for elevated serum urea probably due to dehydration. The obstetric ultrasound scan showed a live fetus with an estimated fetal weight of 2.1 Kg.
The mass was excised, accompanied by evacuation of a pelvic hematoma collection and repair of lacerated tissues. The appearance of the swelling on presentation is shown on [Figure 1]. The excised mass was sent to the histopathology laboratory for processing and evaluation.
|Figure 1: Vulva schwannoma: There was ulceration of the vulva and protrusion of a large oval mass which extended to involve the lower part of the vagina at presentation in the hospital|
Click here to view
Her postoperative recovery was remarkable and she was discharged on the 6th postoperative day. She came for follow-up at 2 weeks, 4 weeks, 8 weeks, and 12 weeks after discharge. The patient remained stable on follow-up after discharge from the hospital. The vulvovaginal wound healed without any evidence of recurrence. The baby was delivered at term via a cesarean section.
A large ovoid encapsulated firm tissue specimen, preserved in formalin, was received and accessioned in the histopathology laboratory. On gross examination, the specimen measured 10.5 × 7 × 6.5 cm, weighed 249.2 grams; had a volume of 201 mls (determined by fluid displacement) and a calculated density of 1.24 g/cm3. The cut section showed a whitish fleshy surface [Figure 2]. Sections cut from the paraffin wax embedded tissue blocks were routinely stained with hematoxylin and eosin. Histological evaluation revealed a classical poorly cellular (Antoni B) and cellular regions (Antoni A). Most of the tumor consisted of the cellular regions made up of fascicles of spindle-shaped cells with indistinct cell borders and elongated serpentine nuclei with tapered ends. The nuclei of these cells were arranged in characteristic palisades separated by clefts of eosinophilic fibrils (Verocay bodies). Average mitotic counts of 2/10 high power fields (hpfs) were observed. The histological features are shown on [Figure 3] and [Figure 4]. There was a strong positive immunohistochemical reaction of the tumor cells to S-100. The observed histological features were consistent with the diagnosis of a conventional benign schwannoma. The tumor lacked degenerative changes, such as cyst formation, necrosis, or foci of calcification.
|Figure 2: Schwannoma of the vulva: The mass consisted of an encapsulated grey brown firm mass with a white fleshy cut surface|
Click here to view
|Figure 3: Schwannoma of the vulva: This microscope section of the cellular Antoni A area of the tumor shows the classical fascicles of Schwann cell palisades (Verocay bodies). X4 objective magnification, H and E|
Click here to view
|Figure 4: Schwannoma of the vulva: Microscope section of the tumor mass showing the serpentine nuclei arranged in pallisades with thin eosinophillic fibrils running across the cleft between the fibrils. X10 objective magnification, H and E|
Click here to view
| Discussion|| |
Mesenchymal tumors in the female reproductive tract range from the commonly occurring leiomyoma to rarely encountered lesions. Mesenchymal tumors in the vagina and vulva regions are not common, especially when compared with epithelial neoplasms. Those of neural origin are still a much smaller subset. Schwannomas which arise from the neural sheath are only rarely encountered in gynecological practice and a few cases have been reported., [Table 1] below shows some cases involving the vulva and adjacent structures reported in the literature.,,,,,,,,,,,,,,,,,,,,, Presented on this table are some important features including the age of the patient, duration of the swelling, histological subtype, specific site, size, and presence or absence of degenerative changes such as necrosis or cyst formation.
In the pelvic region, the tumor may be found attached to the vulva, in the vagina, cervix, uterus, perineum, or rectovaginal pouch. Vulvar region schwannomas have been reported to occur in different locations, such as the clitoris, labia minora, or labia majora. The tumor in the present reported case was found to be arising from the labium majus, consistent with previous observation that most vulvar schwannomas arise from the labia. The encounter of the physician with this tumor should prompt further examination of the patient for other neural tumors such as neurofibromatosis.
The sizes of the reported cases of schwannomas occurring in the perineal region of women vary widely, from the very small, barely palpable to huge masses [Table 1]. Since the tumor grows as a painless swelling, intervention may be sought by the patient either to obviate the swelling metamorphosing into something more sinister, or because movement has become difficult due to pressure effect. The tumor may be present for many years without any further increase in size. The present case is a large mass measuring 10.5 × 7 × 6.5 cm, a size which unavoidable posed movement and other challenges to the patient. An accelerated growth of a schwannoma during pregnancy has been reported in the literature. The rapid growth and exaggeration of the features of the tumor rarely reported in some cases may be directly due to the physiological changes of pregnancy or pressure effects.,, Schwannomas may grow into mammoth-sized masses. There was a report of a huge schwannoma incidentally discovered during a caesarean and removed. It was a huge mass of 40 × 40 cm weighing 6,630 grams, attached by a stalk to the wall of the vagina and extended up into the abdominal cavity. That case is somewhat similar to the present one herein presented considering the large size of the tumor mass and pregnancy of 35 weeks' gestational age.
Degenerative changes in a schwannoma seem to be related to the size of the tumor. The larger masses may be associated with necrosis or calcification. Sometimes, cystic degeneration may occur. There may be significant deposition of hyaline around blood vessels making the walls appear thickened on microscopy. There was no cystic change, necrosis, or calcification observed in the present case. Huge masses are almost invariably associated with necrosis.
A high frequency of mitotic cells is only rarely reported in schwannomas cases because the tumor hardly ever becomes malignant. Most cases of benign vulva schwannoma have low mitosis ranging from none to 3–4 per hpf.,, Malignant schwannomas are associated with frequent mitosis and ultrastructural features such as indented nuclei and absence of Luse bodies. A mitotic rate of 2/10 hpf was observed in the present case being reported. A Ki67 index of 5% and mitotic rate of 3–4/10 hpf was reported by some researcher who presented a case of pleomorphic schwannoma of the vulva. Similar to previous reports, this present case demonstrated strong S-100 immunohistochemical reactivity.
Malignant schwannomas are very infrequent and that of the vulvar is a very rare phenomenon., Metastases usually occur by the hematogenous route.
The patient in the present case was in a stable condition without any evidence of recurrence of the growth several weeks after excision. This is congruent with other reported cases of vulvar schwannomas or those occurring within the pelvic region. Recurrence has occurred only in few instances of reported cases [Table 1]. There seems to be a stable pattern of nonrecurrence once the neoplasm is completely excised.,
| Conclusion|| |
We have presented a case of a pregnant woman with a large ulcerated vulvar mass of long duration which turned out, on histological evaluation, to be a conventional schwannoma. This case contributes to the pool of few worldwide reports of this large neural tumor arising in the vulva.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understand that her names and initials will not be published and due efforts will be made to conceal her identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Kim NR, Cho HY, Lee SH. Vulvar neurilemmoma at the labium minus. Korean J Obs Gynaecol 2011;54:326-9.
Fetsch JF, Laskin WB. Soft tissue lesions involving female reproductive organs. In: Kurman RJ, Ellenson LH, Ronnett BM, editors. Blaustein's Pathology of the Female Genital Tract. Boston, MA: Springer US; 2011. p. 1159-203.
Parra-Herran C, Nucci MR. Soft tissue lesions of the vulva and vagina. In: Diagnostic Gynecologic and Obstetric Pathology. Elsevier Ltd; 2019. p. 197-223.
Ellison DW, MacKenzie IZ, McGee JOD. Cellular schwannoma of the vagina. Gynecol Oncol 1992;46:119-21.
Chen CH, Jeng CJ, Liu WM, Shen J. Retroperitoneal schwannoma mimicking uterine myoma. Taiwan J Obstet Gynecol 2009;48:176-7.
Huang HJ, Yamabe T, Tagawa H. A solitary neurilemmoma of the clitoris. Gynecol Oncol 1983;15:103-10.
CHuang WY, Yeh CJ, Jung SM, Hsueh S. Plexiform schwannoma of the clitoris. APMIS 2007;115:889-90.
Yegane RA, Alaee MS, Khanicheh E. Congenital plexiform schwannoma of the clitoris. Saudi Med J 2008;29:600-2.
Das S, Kalyani R, Harendra Kumar M. Vulval schwannoma: A cytological diagnosis. J Cytol 2008;25:108. [Full text]
Fong KL, Bouwer H, Baranyai J, Jones RW. Ancient Schwannoma of the Vulva. Obstet Gynecol 2009;113(Part 2):510-2.
Yu Y, Kwon D, Park J, Choi S, Ryu S. Schwannoma of the clitoris: A case report. Korean J Obs Gynaecol 2011;54:817-9.
Azurah AGN, Grover S, McGregor D. Plexiform schwannoma of the clitoris in a young girl: A case report. J Reprod Med 2013;58:365-8.
Bozkurt M, Kara D. Giant Vulvar Schwannoma: A case report. Acta Med Iran 2013;51:427-9.
Park ST, Kim HM, Shin MK, Kim JW. An unusual case of vulvar schwannoma. World J Surg Oncol 2015;13:139.
Bafna B, Bafna A, Bafna A. Case report vulvar schwannoma: A case report. Int J Reprod Contracept Obstet Gynecol 2016;5:3249-50.
Panwar D, Narayana SM, Patil GV. Case report- plexiform schwannoma of vulva with brief review of literature. Int J Curr Med Pharm Res 2017;3:2062-4.
Woodruff JM, Marshall ML, Godwin TA, Funkhouser JW, Thompson NJ, Erlandson RA. Plexiform (multinodular) schwannoma. A tumor simulating the plexiform neurofibroma. Am J Surg Pathol 1983;7:691-7.
An X, Zhu M, Zhang N, Lu S, Wei P, Jiang L, et al
. Schwannoma of the vagina-a common tumor but a rare location: A case report. Mol Clin Oncol 2017;7:783-6.
Tan J, Chen J, Yang L. A case of vulvar schwannoma mimicking epidermoid cyst. Case Rep Dermatol 2018;10:41-5.
Yamashita Y, Yamada T, Ueki K, Ueki M, Sugimoto O. A case of vulvar schwannoma. J Obstet Gynaecol Res 1996;22:31-4.
Hanafy A, Lee RM, Peterson CM. Schwannoma Presenting as a Bartholin's Gland Abscess. Aust New Zeal J Obstet Gynaecol 1997;37:483-4.
Quesada G, Solera JC, Sanchez-Bartolomé J, Vazquez F, López-García L. Benign Schwannoma of the Vulva: A Case Report. J Gynecol Surg 1998;14:195-8.
Santos LD, Killingsworth MC, Currie BG. Case report: Plexiform schwannoma of the vulva. Pathology 2001;33:526-31.
Llaneza P, Fresno F, Ferrer J. Schwannoma of the clitoris. Acta Obstet Gynecol Scand 2002;81:471-2.
Fujimoto E, Onishi Y, Tajima S, Okura T. Vulvar Schwannoma. Rinsho Derma 2004;46:548-9.
Agaram NP, Prakash S, Antonescu CR. Deep-seated plexiform schwannoma: A pathologic study of 16 cases and comparative analysis with the superficial variety. Am J Surg Pathol 2005;29:1042-8.
Padmanaban N, Chandrabose PS, Esakki M, Kirubamani H, Srinivasan C. Gynaecological perspective of schwannoma: A rare pelvic tumour. J Clin Diagnostic Res 2016;10:QD03-QD05.
Majbar A, Hrora A, Jahid A, Ahallat M, Raiss M. Perineal schwannoma. BMC Res Notes 2016;9:304.
Kellogg A, Watson WJ. Malignant schwannoma in pregnancy: A case report and literature review. Am J Perinatol 2010;27:201-4.
Tacken CTM, Ramakers PB, Idema JSA, Van der Hoeven GJ. Unexpected schwannoma unmasked by the physiologic changes of pregnancy. Clin Case Reports Rev 2016;2:509-11.
Giasna GK, Micu MC, Micu R. Schwannoma of the median nerve mimicking carpal tunnel syndrome in a pregnant patient. Case report. Med Ultrason 2016;18:521-3.
Mizuguchi S, Inoue K, Imagawa A, Kitano Y, Kameyama M, Ueda H, et al
. Benign esophageal schwannoma compressing the trachea in pregnancy. Ann Thorac Surg 2008;85:660-2.
Yaseen EM, Mola EA, Zabeedy AA. Vaginal schwannoma: A case report. Tikrit Med J 2008;14:218-20.
Panwar P, Kumar S, Singh S, Sriharsha AS, Gupta K. Giant abdominoperineal malignant schwannoma: An unusual presentation and surgical challenge. Case Rep Urol 2015;2015:1-5.
Lawrence WD, Shingleton HM. Malignant schwannoma of the vulva: A light and electron microscopic study. Gynecol Oncol 1978;6:527-37.
Terada KY, Schmidt RW, Roberts JA. Malignant schwannoma of the vulva. A case report. J Reprod Med 1988;33:969-72.
[Figure 1], [Figure 2], [Figure 3], [Figure 4]