Case report

A gastrointestinal stromal tumor (GIST) masquerading as an ovarian mass

Giorgio Carlomagno¹ and Pasquale Beneduce²

¹  Università di Roma "La Sapienza" – Corso di Laurea in Ostetricia, U. O. C. Ginecologia e Ostetricia – A.O. "G. Rummo", Benevento, Italy

²  U. O. C. Chirurgia d'Urgenza – A. O. 'U Rummo", Benevento, Italy

author email corresponding author email

World Journal of Surgical Oncology 2004, 2:15doi:10.1186/1477-7819-2-15

The electronic version of this article is the complete one and can be found online at: http://www.wjso.com/content/2/1/15

Received:	18 February 2004
Accepted:	13 May 2004
Published:	13 May 2004

© 2004 Carlomagno and Beneduce; licensee BioMed Central Ltd. This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original URL.

Keywords: Gastrointestinal stromal tumors, GIST, ovarian neoplasm

Abstract

Background

Malignant gastrointestinal stromal tumors (GIST) are rare mesenchymal tumors originating in the wall of the gastrointestinal tract. Myogenic gastrointestinal stromal tumor, a distinctive morphologic variant is characterized by an unusually prominent myxoid stromal background.

Case presentation

We report a case of myxoid variant of GIST in a 42 years old woman presenting as an epigastric mass associated to an ovarian cyst and elevated CA-125. Histologically, the lesions was composed of a proliferation of spindle cells in an abundant myxoid stroma, without evidence of atypia or anaplasia. Immunohistochemical stains showed strong positive staining with muscle actin, positive staining with CD34 and weak positive staining with CD117, while showed negative for S-100.

Conclusion

At surgery every effort should be made to identify the origin of the tumor. A complete surgical removal of the tumor should be obtained, as this is the only established treatment that offers long term survival.

Background

Gastrointestinal stromal tumors (GIST) are rare tumors that may arise anywhere in the tubular gastrointestinal tract, but stomach is the most common site of localization. Surgery is the main stay of treatment and complete resection is achieved in most of cases [1]. The 5 year overall survival ranges from 21% to 88% in different series, depending from risk grading and completeness of surgical resection [1-4]. In light of the tendency of these tumors to pursue an indolent clinical course with a significant risk of late relapse, a brisk follow-up is advocated for all patients [5]. Imatinib mesylate is proposed as therapy for high risk GISTs after surgery [6]. A distinctive morphologic variant of gastrointestinal stromal tumor has been described, characterized by a prominent myxoid stromal background reminiscent of a neural neoplasm but lacking the immunohistochemical or ultrastructural features of peripheral nerve sheath or ganglionic differentiation. This variant is more frequent in women and mostly occurs in the stomach. These lesions are described grossly as well circumscribed, unencapsulated, with a prominently myxoid and often cystic cut surface [7]. We report a case of myxoid variant GIST, occurring in a 42 year old woman.

Case presentation

A 42-year-old woman presented with pelvic pain, palpable pelvic mass extended to the epigastric region, and elevated CA-125 (61.8 U/ml). Computed tomography (CT) imaging showed a left 6 × 5 cm cystic ovarian lesion and a 12 × 9.5 cm solid mass in the epigastric region (figure 1, 2). A preoperative diagnosis of metastatic ovarian malignancy or FIGO stage III ovarian malignancy was made. At laparotomy, a left ovarian cyst was seen along with a solid mass attached to the greater curvature of stomach which was easily dissected from it. Histologically, the lesions was composed of a proliferation of spindle cells embedded in an abundant myxoid stroma, without evidence of frank atypia or anaplasia. Histochemical stains showed strong positive staining with muscle actin, positive staining with CD34 and weak positive staining with CD117, while it was negative for S-100. The histological work up was conclusive for a low malignancy GIST – myxoid variant, being the mass volume the only risk factor [3,5], the ovarian mass on the other hand was a follicular cyst. Due to the lack of clear risk factors for recurrence, and to complete surgical tumor resection, the patient was advised follow-up only.

Discussion

Fletcher et al., [5] classified these tumors in to very low, low, intermediate and high risk, categories according to tumor size and mitotic count. Tumors <2 cm and mitotic count <5/50 high power field (HPF) were categorized as very low risk; tumor size 2–5 cm and mitotic count <5/50 HPF as low risk; tumor size <5 cm and mitotic count 6–10/50 HPF or tumor size 5–10 cm and mitotic count <5/50 HPF as intermediate risk; tumor size >5 cm and mitotic count >5/50 HPF or tumor size >10 cm and any mitotic rate or tumor any size and mitotic rate >10/50 HPF as high risk. As reported by others [8-10], GIST may mimic a pelvic masses. In such circumstances they are first noticed by gynecologists and are often diagnosed, prior to surgery, as ovarian tumors, either as metastatic from, or metastatizing to gastrointestinal tract. Only at surgery their nature is fully understood. The same was true in our case as a solid epigastric mass was associated to an ovarian cystic lesion similar to that in Krukenberg tumor. Therefore, in presence of a pelvic mass, especially if other unusual signs are present, the possibility of other than a gynecologic tumor has to be considered. At surgery, every effort should be made to identify the origin of the tumor and related anatomic structures. In the case of GIST, a complete surgical removal of the tumor should be obtained, as despite significant advances in new chemotherapic regimens have been radical surgical removal only offers chance of long term survival.

Competing interests

None declared.

Authors' contributions

All authors conceived of the study, and participated in its design and coordination. All authors read and approved the final manuscript.

Acknowledgements

Written consent was obtained from the patient or their relative for publication of study.

References

1. Besana-Ciani I, Boni L, Dionigi G, Benevento A, Dionigi R: Outcome and long-term results of surgical resection for gastrointestinal stromal tumors (GIST).

   Scand J Surg 2003, 92:195-199. PubMed Abstract

2. Liberati G, Lucchetta MC, Petraccia L, Nocchi S, Rosentzwig R, De Matteis A, Grassi M: Meta-analytical study of gastrointestinal stromal tumors (GIST).

   Clin Ter 2003, 154:85-91. PubMed Abstract

3. Singer S, Rubin BP, Lux ML, Chen CJ, Demetri GD, Fletcher CD, Fletcher JA: Prognostic value of KIT mutation type, mitotic activity, and histologic subtype in gastrointestinal stromal tumors.

   J Clin Oncol 2002, 20:3898-3905. PubMed Abstract | Publisher Full Text

4. Crosby JA, Catton CN, Davis A, Couture J, O'Sullivan B, Kandel R, Swallow CJ: Malignant gastrointestinal stromal tumors of the small intestine: a review of 50 cases from a prospective database.

   Ann Surg Oncol 2001, 8:50-59. PubMed Abstract | Publisher Full Text

5. Fletcher CD, Berman JJ, Corless C, Gorstein F, Lasota J, Longley BJ, Miettinen M, O'Leary TJ, Remottí H, Rubin BP, Shmookler B, Sobin LH, Weiss SW: Diagnosis of gastrointestinal stromal tumors: a consensus approach.

   Int J Surg Pathol 2002, 10:81-89. PubMed Abstract

6. DeMatteo RP: The GIST of targeted cancer therapy: a tumor (gastrointestinal stromal tumor), a mutated gene (c-kit), and a molecular inhibitor (ST1571).

   Ann Surg Oncol 2002, 9:831-839. PubMed Abstract | Publisher Full Text

7. Suster 9, Sorace D, Moran CA: Gastrointestinal stromal tumors with prominent myxoid matrix. Clinicopathologic, immunohistochemical, and ultrastructural study of nine cases of a distinctive morphologic variant of myogenic stromal tumor.

   Am J Surg Pathol 1995, 19:59-70. PubMed Abstract

8. Zighelboim I, Henao G, Kunda A, Gutierrez C, Edwards C: Gastrointestinal stromal tumor presenting as a pelvic mass.

   Gynecol Oncol 2003, 91:630-635. PubMed Abstract | Publisher Full Text

9. Belics Z, Csapo Z, Szabo I, Papay J, Szabo J, Papp Z: Large gastrointestinal stromal tumor presenting as an ovarian tumor. A case report.

   J Reprod Med 2003, 48:655-658. PubMed Abstract

10. Foti MA, Currao AA, Palano AD, Nuciforo G: GIST in ginecologia: aspetti clinici.

    In Atti della Società Italiana di Ginecologia e Ostetricia, Congresso di Catania Ottobre 2003 v. 2, CIC Edizioni Internazionali, Roma 2003, 496-499.

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