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An unusual cause of adnexal mass: fallopian tube schwannoma
Gynecologic Oncology 92 (2004) 343 – 346 www.elsevier.com/locate/ygyno
Case Report
An unusual cause of adnexal mass: fallopian tube schwannoma Bulent Duran, a,* Tevfik Guvenal, a Esin Yıldız, b Meral Cetin, a Omur Erden, a and Nihal Demirkoprulu a a
Department of Obstetrics and Gynecology, Cumhuriyet University School of Medicine, 58140 Sivas, Turkey b Department of Pathology, Cumhuriyet University School of Medicine, 58140 Sivas, Turkey Received 4 April 2003
Abstract Background. Schwannoma is a well-defined, usually benign tumor arising from the Schwann cells in the nerve sheath. It can present in any location as a solitary mass; however, it is rarely found in the pelvis. Case. We report a 40-year-old female patient with a pelvic mass, which revealed tubal schwannoma after complete resection of the mass and uterus by laparotomy. Conclusion. Schwannomas are thought to result from a proliferation of perineural cells. Although origin along the nerves of the retroperitoneal space is not uncommon, these tumors rarely present as pelvic masses. D 2003 Elsevier Inc. All rights reserved. Keywords: Pelvic mass; Schwannoma; Fallopian tube
Introduction Schwannoma is a well-defined, usually benign tumor arising from the Schwann cells in the nerve sheath [1]. Although these neoplasms may originate at any anatomic site, tumors of the sacral plexus are exceedingly rare. Most of them are benign tumors, which are detected accidentally when they enlarge [2]. We report a 40-year-old female patient with a pelvic mass, which turned out to be a tubal schwannoma.
Case report A 40-year-old female patient complaining of right pelvic pain and distention of about 2 months’ duration was admitted to our gynecology clinics. Urination and defecation were normal, and she had no fever, vomiting or diarrhea. Pelvic examination revealed a nontender palpable mass in the right adnexal region. The other physical examination findings and general laboratory tests were normal.
* Corresponding author. Fax: +90-346-2191459. E-mail address: [email protected] (B. Duran). 0090-8258/$ - see front matter D 2003 Elsevier Inc. All rights reserved. doi:10.1016/j.ygyno.2003.09.032
Abdominal ultrasound showed a bigger uterus and a 26 18 cm partly cystic mass in the right adnexal region. Left adnexal region was normal. Doppler ultrasound examination was done and mass thought to be non-malign. Serum levels of CA-125, CA-19-9, CA-15-3, CEA, and h-HCG were normal. There were no pathologic changes in the endometrial sampling of the uterus that performed preoperatively. At laporotomy, a mobile, 26 18 cm mass originating from the right adnexal space was found (Fig. 1). Preoperative abdominal washing had shown benign cytology. The uterus nearly 4 months large. Left adnexal was normal. Total abdominal hysterectomy, unilateral oophorectomy, and excision of the mass were performed. The patient was discharged after an uneventful postoperative course on the fifth postoperative day. For 14 months after the operation, she is well and there is no any evidence related to recurrence of the mass. Macroscopically, tumor was an encapsulated, pink-red with 26 18 8 cm diameter arising as an eccentric growth from the wall of the tuba uterine (Fig. 2). Microscopic examination of the mass showed the typical features of a neurilemoma. Some areas demonstrated compact spindle cells arranged in short interlacing fascicles (Antoni A). Other areas within the tumor were characterized by spindle cells within a loose matrix containing scattered
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Fig. 1. Gross appearance of right tubal mass and uterus.
inflammatory cells (Antoni B) and there were typically vessels with perivascular hyalinization in the cellular areas. Immunohistochemically, tumoral cells showed positive reaction with S-100 protein (Figs. 3 and 4).
Discussion Benign solitary schwannomas are uncommon soft tissue tumors [3,4]. They can arise in peripheral, cranial, or sympathetic nerves at virtually any anatomic site. Although
origin along the nerves of the retroperitoneal space is not uncommon, these tumors rarely present as pelvic masses. In this case, it may have originated from the peripheric fibers of the nerves of the sacral plexus and then circumscribed the right tuba of the uterus. These tumors are thought to result from a proliferation of perineural Schwann cells. To this date, the known cases of benign retroperitoneal schwannoma are about 60, of which less than 20 in the pelvis [5]. Solitary intra-abdominal schwannoma usually remain asymptomatic and attain a considerable size before being
Fig. 2. Macroscopic appearance of the mass.
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B. Duran et al. / Gynecologic Oncology 92 (2004) 343–346
Fig. 3. Microscopic appearance of the mass (HE, 75).
discovered. Often they are discovered incidentally and are not clinically apparent. Ultrasonography, CT or MRI are the most useful investigations, although they cannot determine the exact nature of the tumor [6]. Characteristic CT findings of schwannoma have been reported [7]. The mass presents a heterogeneous pattern with peripheral areas of enhancement on contrast examination. This heterogeneity corresponds with the histological appearances which show areas of hypocellularity, hypercellularity and cystic degeneration and, rarely, calcification [7]. Although these features are typical of the tumor, they are not diagnostic and a final diagnosis can only
be made histologically. Unless there is evidence of tumor spread or local invasion, there are no preoperative markers of malignancy. Schwannoma is generally an encapsulated solitary tumor. On cut surface, it is tan or gray, with occasional areas of cystic degeneration and prominent vascularity. Histologically, the terms Antoni type A neurilemoma and type B neurilemoma are used to describe varying growth patterns in schwannomas. Type A tissue has elongated spindle cells arranged in irregular streams and is compact in nature. Nuclei are long and oval, with minimal associated cytoplasm [1,8]. Type B tissue has a looser organization, often
Fig. 4. Microscopic appearance of the mass (HE, 300) and positivity with S-100 protein in the upper right (HE, 300).
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with cystic spaces intermixed within the tissue. Tumors originating in Schwann cells can be detected at immunohistochemical examination by virtue of their positive results with S-100 antigen tests. In this case, the tumor was distinguished with the presence of its capsule and S100 positive cells from neurofibromas, smooth muscle tumors, and another possible soft tissue tumor such as hemangiopericytoma. Appropriate management of schwannomas depends on several factors, including symptoms, age, and health of the patient. The treatment of choice is complete excision. Recurrence or persistence seems to be associated with incomplete resection, which occurred in 10% of the reported cases. Malignant transformation is rare [1]. In this report, we described a benign schwannoma with tubal location discovered in a gynecological operation made for an adnexal mass. The clinicopathologic features of this rare tumor were presented and the literature was reviewed.
References [1] Whitaker WG, Droulias C. Benign encapsulated neurilemoma: a report of 76 cases. Am Surg 1976;42:675 – 8. [2] Melvin WS. Laparoscopic resection of a pelvic schwannoma. Surg Laparosc Endosc 1996;6:489 – 91. [3] Noonan JD, Minagi H, Margolin FR. Benign, solitary schwannomas of the lesser peritoneal sac. Am J Roentgenol Radium Ther Nucl Med 1975;125:391 – 4. [4] Jacobs RL, Barmada R. Neurilemoma. A review of the literature with six case reports. Arch Surg 1971;102:181 – 6. [5] Borghese M, Corigliano N, Gabriele R, Antoniozzi A, Izzo L, Barbaro M, et al. Benign schwannoma of the pelvic retroperitoneum. Report of a case and review of the literature. G Chir 2000;21:232 – 8. [6] Aubert J, Debiais F, Levillain P. Schwannoma of the obturator nerve with urologic manifestations: report of a case. Ann Urol 2000;34:58 – 65. [7] Cohen LM, Schwartz AM, Rockoff SD. Benign schwannomas: pathologic basis for CT inhomogeneities. AJR Am J Roentgenol 1986;147: 141 – 3. [8] Lazarus SS, Trombetta LD. Ultrastructural identification of a benign perineural cell tumor. Cancer 1978;41:1823 – 9.
Case Report
An unusual cause of adnexal mass: fallopian tube schwannoma Bulent Duran, a,* Tevfik Guvenal, a Esin Yıldız, b Meral Cetin, a Omur Erden, a and Nihal Demirkoprulu a a
Department of Obstetrics and Gynecology, Cumhuriyet University School of Medicine, 58140 Sivas, Turkey b Department of Pathology, Cumhuriyet University School of Medicine, 58140 Sivas, Turkey Received 4 April 2003
Abstract Background. Schwannoma is a well-defined, usually benign tumor arising from the Schwann cells in the nerve sheath. It can present in any location as a solitary mass; however, it is rarely found in the pelvis. Case. We report a 40-year-old female patient with a pelvic mass, which revealed tubal schwannoma after complete resection of the mass and uterus by laparotomy. Conclusion. Schwannomas are thought to result from a proliferation of perineural cells. Although origin along the nerves of the retroperitoneal space is not uncommon, these tumors rarely present as pelvic masses. D 2003 Elsevier Inc. All rights reserved. Keywords: Pelvic mass; Schwannoma; Fallopian tube
Introduction Schwannoma is a well-defined, usually benign tumor arising from the Schwann cells in the nerve sheath [1]. Although these neoplasms may originate at any anatomic site, tumors of the sacral plexus are exceedingly rare. Most of them are benign tumors, which are detected accidentally when they enlarge [2]. We report a 40-year-old female patient with a pelvic mass, which turned out to be a tubal schwannoma.
Case report A 40-year-old female patient complaining of right pelvic pain and distention of about 2 months’ duration was admitted to our gynecology clinics. Urination and defecation were normal, and she had no fever, vomiting or diarrhea. Pelvic examination revealed a nontender palpable mass in the right adnexal region. The other physical examination findings and general laboratory tests were normal.
* Corresponding author. Fax: +90-346-2191459. E-mail address: [email protected] (B. Duran). 0090-8258/$ - see front matter D 2003 Elsevier Inc. All rights reserved. doi:10.1016/j.ygyno.2003.09.032
Abdominal ultrasound showed a bigger uterus and a 26 18 cm partly cystic mass in the right adnexal region. Left adnexal region was normal. Doppler ultrasound examination was done and mass thought to be non-malign. Serum levels of CA-125, CA-19-9, CA-15-3, CEA, and h-HCG were normal. There were no pathologic changes in the endometrial sampling of the uterus that performed preoperatively. At laporotomy, a mobile, 26 18 cm mass originating from the right adnexal space was found (Fig. 1). Preoperative abdominal washing had shown benign cytology. The uterus nearly 4 months large. Left adnexal was normal. Total abdominal hysterectomy, unilateral oophorectomy, and excision of the mass were performed. The patient was discharged after an uneventful postoperative course on the fifth postoperative day. For 14 months after the operation, she is well and there is no any evidence related to recurrence of the mass. Macroscopically, tumor was an encapsulated, pink-red with 26 18 8 cm diameter arising as an eccentric growth from the wall of the tuba uterine (Fig. 2). Microscopic examination of the mass showed the typical features of a neurilemoma. Some areas demonstrated compact spindle cells arranged in short interlacing fascicles (Antoni A). Other areas within the tumor were characterized by spindle cells within a loose matrix containing scattered
344
B. Duran et al. / Gynecologic Oncology 92 (2004) 343–346
Fig. 1. Gross appearance of right tubal mass and uterus.
inflammatory cells (Antoni B) and there were typically vessels with perivascular hyalinization in the cellular areas. Immunohistochemically, tumoral cells showed positive reaction with S-100 protein (Figs. 3 and 4).
Discussion Benign solitary schwannomas are uncommon soft tissue tumors [3,4]. They can arise in peripheral, cranial, or sympathetic nerves at virtually any anatomic site. Although
origin along the nerves of the retroperitoneal space is not uncommon, these tumors rarely present as pelvic masses. In this case, it may have originated from the peripheric fibers of the nerves of the sacral plexus and then circumscribed the right tuba of the uterus. These tumors are thought to result from a proliferation of perineural Schwann cells. To this date, the known cases of benign retroperitoneal schwannoma are about 60, of which less than 20 in the pelvis [5]. Solitary intra-abdominal schwannoma usually remain asymptomatic and attain a considerable size before being
Fig. 2. Macroscopic appearance of the mass.
345
B. Duran et al. / Gynecologic Oncology 92 (2004) 343–346
Fig. 3. Microscopic appearance of the mass (HE, 75).
discovered. Often they are discovered incidentally and are not clinically apparent. Ultrasonography, CT or MRI are the most useful investigations, although they cannot determine the exact nature of the tumor [6]. Characteristic CT findings of schwannoma have been reported [7]. The mass presents a heterogeneous pattern with peripheral areas of enhancement on contrast examination. This heterogeneity corresponds with the histological appearances which show areas of hypocellularity, hypercellularity and cystic degeneration and, rarely, calcification [7]. Although these features are typical of the tumor, they are not diagnostic and a final diagnosis can only
be made histologically. Unless there is evidence of tumor spread or local invasion, there are no preoperative markers of malignancy. Schwannoma is generally an encapsulated solitary tumor. On cut surface, it is tan or gray, with occasional areas of cystic degeneration and prominent vascularity. Histologically, the terms Antoni type A neurilemoma and type B neurilemoma are used to describe varying growth patterns in schwannomas. Type A tissue has elongated spindle cells arranged in irregular streams and is compact in nature. Nuclei are long and oval, with minimal associated cytoplasm [1,8]. Type B tissue has a looser organization, often
Fig. 4. Microscopic appearance of the mass (HE, 300) and positivity with S-100 protein in the upper right (HE, 300).
346
B. Duran et al. / Gynecologic Oncology 92 (2004) 343–346
with cystic spaces intermixed within the tissue. Tumors originating in Schwann cells can be detected at immunohistochemical examination by virtue of their positive results with S-100 antigen tests. In this case, the tumor was distinguished with the presence of its capsule and S100 positive cells from neurofibromas, smooth muscle tumors, and another possible soft tissue tumor such as hemangiopericytoma. Appropriate management of schwannomas depends on several factors, including symptoms, age, and health of the patient. The treatment of choice is complete excision. Recurrence or persistence seems to be associated with incomplete resection, which occurred in 10% of the reported cases. Malignant transformation is rare [1]. In this report, we described a benign schwannoma with tubal location discovered in a gynecological operation made for an adnexal mass. The clinicopathologic features of this rare tumor were presented and the literature was reviewed.
References [1] Whitaker WG, Droulias C. Benign encapsulated neurilemoma: a report of 76 cases. Am Surg 1976;42:675 – 8. [2] Melvin WS. Laparoscopic resection of a pelvic schwannoma. Surg Laparosc Endosc 1996;6:489 – 91. [3] Noonan JD, Minagi H, Margolin FR. Benign, solitary schwannomas of the lesser peritoneal sac. Am J Roentgenol Radium Ther Nucl Med 1975;125:391 – 4. [4] Jacobs RL, Barmada R. Neurilemoma. A review of the literature with six case reports. Arch Surg 1971;102:181 – 6. [5] Borghese M, Corigliano N, Gabriele R, Antoniozzi A, Izzo L, Barbaro M, et al. Benign schwannoma of the pelvic retroperitoneum. Report of a case and review of the literature. G Chir 2000;21:232 – 8. [6] Aubert J, Debiais F, Levillain P. Schwannoma of the obturator nerve with urologic manifestations: report of a case. Ann Urol 2000;34:58 – 65. [7] Cohen LM, Schwartz AM, Rockoff SD. Benign schwannomas: pathologic basis for CT inhomogeneities. AJR Am J Roentgenol 1986;147: 141 – 3. [8] Lazarus SS, Trombetta LD. Ultrastructural identification of a benign perineural cell tumor. Cancer 1978;41:1823 – 9.