Case Report

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Licensee OA Publishing London 2013. Creative Commons Attribution Licence (CC-BY)

F : Skafida E, Tsavari A, Koulia K, Myoteri D, Grammatoglou X, Zisi A, et al. Εxtragenital Adenomatoid tumour of the omentum: an unusual location. OA Case Reports 2013 Jan 31;2(1):4.

Εxtragenital adenomatoid tumour of the omentum:an unusual location

E Skafida1*, A Tsavari1, K Koulia1, D Myoteri1, X Grammatoglou1,A Zisi2, M Varras3, T Vasilakaki1

AbstractIntroductionAdenomatoid tumours are benig-n neoplasms that are mesothelial in origin and are usually confined to the genital tract and have rarely been reported at other sites such as the omentum, pleura, heart, liver, adrenal gland, retroperitoneum and intestinal mesentery. This pap-er discusses the unusual location of an extragenital adenomatoid tumour of the omentum.Case reportWe report the case of a 32-year-old woman who presented to our hospital with a four-day history of fever and pain in the right iliac fossa. Ultrasonography revealed a right ovarian cyst which was 2.5 cm in diameter and fluid in douglaseio. A right partial oopho-rectomy was performed, and duri-ng the operation, a well circu-mscribed mass measuring 2 cm was observed in the omentum. Histological evaluation of the cyst showed features of a cracked lute-al cyst and the mass showed feat-ures of an adenomatoid tumour. In the immunohistochemical study, the lesional cells were positive for calretinin, D240, CK5/6, HMBE1, CKAE1, CKAE3 and calponin. The treatment in such cases is tumour excision. We report the case of an unusual extragenital adenomatoid tumour.

ConclusionAdenomatoid tumours are often found incidentally during surgical procedures. Tumour excision is therefore the treatment of choice.

IntroductionAdenomatoid tumours are benign neoplasms that are mesothelial in origin and are usually confined to the genital tract. In men, these tumours occur in the epididymis, testicular tunics, prostate, sper-matic cord and the parenchyma of the testis. In women, these tumours have been reported to occur in the uterus, fallopian tubes and rarely in the ovaries1,2,3,4. However, rare, extra-genital adenomatoid tumours have been reported at other sites such as the omentum, pleura, heart, liver, adrenal gland, retroperitoneum, intestinal mesentery and lymph nodes5,6,7,8. Initially, its mesothelial origin was suggested in 1942, but the term ‘adenomatoid tumour’ was coined by Golden and Ash in 19459. Today, the mesothelial differentia-tion of adenomatoid tumours is well recognised from the histology, immu-nophenotype and ultrastructure of these tumours1,2,10. In this report, we have described another unusual loca-tion for adenomatoid tumours.

Case reportWe report the case of a 32-year-old woman who presented to our hospital with a fourday history of fever and pain in the right iliac fossa. There was no family history of malignancy. Laboratory investiga-tion including complete blood count, biochemical examination and tumour markers (CEA, Ca19-9, Ca125), was normal. Ultrasound and abdominal and pelvic computed tomography

revealed a right ovarian cyst which was 2.5 cm in diameter and fluid in douglaseio. A right partial oopho-rectomy was performed, and during the operation, a well-circumscribed mass measuring 2 cm was observed in the omentum. Histological evalu-ation of the cyst showed features of a cracked luteal cyst. On microscopic examination, the mass had a vari-able structural pattern consisting of cysts, tubular channels and gland-like spaces lined by flattened or cuboidal cells. Many cells had vacu-olated cytoplasms and signet-ring or lipoblastlike cell morphology. Stroma consisted of loose or dense collagen tissue with hyalinisation. Marked cytologic atypia, tumour cell necrosis or mitotic figures were not seen (Figures 1[A] and 1[B]). In the immunohistochemical study, the lesional cells were posi-tive for calretinin, D240, CK5/6, HMBE1, CKAE1, CKAE3 and calponin (Figure 2). Histochemical analysis of the tumour showed a lack of mucin, a feature aiding distinction from meta-static adenocarcinoma. Based on the above characteristic morphological and immunohistochemical findings, a diagnosis of adenomatoid tumour was made. The patient was free of recurrence three years after surgery.

DiscussionThe mesothelial origin of adenoma-toid tumours is widely accepted and is supported by electron micros-copy and immunohistochemical studies. However, multiple histoge-netic origins have been proposed for these tumours by different authors, including mesothelial, mesonephric, müllerian and endothelial origins1,2,10. The reason for an apparent predomi-nance of these tumours in the genital

* Corresponding authorEmail: evelinaskafida@yahoo.gr1 Department of Pathology, ‘Tzaneion’ General

Hospital of Piraeus, Greece2 Department of Chemistry, University of Ath-

ens ‘kapodistriako’, Greece3 Third Department of Obstetrics and Gynae-

cology, ‘Elena Venizelou’ General Maternity State Hospital, Athens, Greece

Onco

logy

Licensee OA Publishing London 2013. Creative Commons Attribution Licence (CC-BY)

F : Skafida E, Tsavari A, Koulia K, Myoteri D, Grammatoglou X, Zisi A, et al. Εxtragenital Adenomatoid tumour of the omentum: an unusual location. OA Case Reports 2013 Jan 31;2(1):4.

Case Report

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tract has not been explained. Adeno-matoid tumours have a distinct but variable structural pattern ranging from irregularly arranged, dilated tubular channel, cysts and gland-like spaces lined by flattened or cuboidal cells to solid nests. Many cells have vacuolated cytoplasms and a signet-ring or lipoblast-like cell morphology. Stroma may consist of loose or dense collagen tissue with hyalini-sation and may contain aggregates of lymphocytes. A variety of immu-nohistochemical markers have been reported to identify adenomatoid tumours such as calretinin, CK5/6, D240, caldesmon, CKAE1, CKAE3, caplonin, HMBE1 and WT11,2,11,12,13. Calretinin is a calcium binding protein that is located both in the cytoplasm as well as the cell nucleus and has a high sensitivity for identi-fying mesothelial cells. Adenomatoid tumours do not express the vascular markers CD31, CD34 and factor VIII1,2,7,12. These tumours are usually solitary and patients are commonly asymptomatic. The tumours are often found incidentally during radiological examination or surgical procedures1,2,7. Some case reports describe multiple adenomatoid tumours occurring mainly in the genital tract13,14,15. Although adeno-matoid tumours have a distinct histological appearance, their differ-ential diagnosis maybe problem-

atic, including vascular neoplasms, germ-cell tumours, malignant meso-thelioma and metastatic adenocarci-noma. Adenomatoid tumours may be difficult to diagnose on frozen section examination especially when rare, extragenital adenomatoid tumours are incidental surgical findings2,7,14.

ConclusionAdenomatoid tumours are often found incidentally during surgical procedures. Tumour excision is therefore the treatment of choice.

ConsentWritten informed consent was obtained from the patient for publi-cation of this case report and accom-panying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.

References1. Maestro MA, Tur Gonzalez R, Alonso Dorrego JM, De la Peña Barthel J, Nistal Martin De Serrano M. Adenomatoid tumors of the epididymis and testicle: report of 9 cases and bibliographic review. Arch Esp Urol. 2009 Mar;62(2):137–14. Spanish. 2. Sangoi AR, Mckenney JK, Schwartz EJ, Rouse RV, Longacre TA. Adenomatoid tumors of the female and male genital tracts: a clinicopathological and immu-nohistochemical study of 44 cases. Mod Pathol. 2009 Sep;22(9):1228–35.3. Nogales FF, Isaac MA, Hardisson D, Bosincu L, Palacios J, Ordi J, et al. Adeno-

matoid tumors of the uterus: an analysis of 60 cases. Int J Gynecol Pathol. 2002 Jan;21(1):34–40.4. Huany CC, Chang DY, Chen CK, Chou YY, Huang SC. Adenomatoid tumor of the female genital tract. Int J Gynaecol Obstet. 1995 Sep;50(3):275–80.5. Nagata S, Aishima S, Fukuzawa K, Takagi H, Yonemasu H, Iwashita Y, et al. Adenomatoid tumor of the liver. J Clin Pathol. 2008 Jun;61(6):777–80.6. Timonera ER, Paiva ME, Lopes JM, Eloy C, van der Kwast T, Asa SL. Composite adenomatoid tumor and myelolipoma of adrenal gland: report of 2 cases. Arch Pathol Lab Med. 2008 Feb;132(2):265–7.7. Isotalo PA, Nascimento AG, Trastek VF, Wold LE, Cheville JC. Extragenital adenomatoid tumor of a mediastinal lymph node. Mayo Clin Proc. 2003 Mar;78(3):350–4.8. Simpson PR. Adenomatoid tumor of the adrenal gland. Arch Pathol Lab Med. 1990 Jul;114(7):725–7.9. Golden A, Ash JE. Adenomatoid tumors of the genital tract. Am J Pathol. 1945 Jan;21(1):63–79.10. Delahunt B, Edle JN, King JN, Bethwaite PB, Nacey JN, Tjornton A. Immunohisto-chemical evidence for mesothelial origin of paratesticular adenomatoid tumor. Histopathology. 2000 Feb;36(2):109–15.11. Schwartz EJ, Longacre TA. Adeno-matoid tumors of the female and male genital tracts express WT1. Int J Gynecol Pathol. 2004 Apr;23(2):123–8.12. Goddard MJ, Grant JW. Adenomatoid tumors: a mucin histochemical and immu-nohistochemical study: Histopathology. 1992 Jan;20(1):57–61.

Figure 1: Microscopically, the cells of the tumour have a vacuolated cytoplasm and a signet-ring or lipoblast-like cell morphology; the stroma consists of loose or dense collagen tissue with hyalinisation. Marked cytologic atypia, tumour cell necrosis or mitotic figures, are not present. Figure 1(A): haematoxylin and eosin × 100. Figure 1(B): haematoxylin and eosin × 400.

Figure 2: Positivity for calretinin (immunostaining × 100).

Case Report

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Licensee OA Publishing London 2013. Creative Commons Attribution Licence (CC-BY)

F : Skafida E, Tsavari A, Koulia K, Myoteri D, Grammatoglou X, Zisi A, et al. Εxtragenital Adenomatoid tumour of the omentum: an unusual location. OA Case Reports 2013 Jan 31;2(1):4.

13. Hayes SJ, Clark P, Mathias R, Formela L, Vickers J, Armstrong GR. Multiple adeno-matoid tumors in the liver and perito-neum. J Clin Path. 2007 Jun;60(6):722–4.

14. Hanada S, Okumura Y, Kaida K. Multi-centric adenomatoid tumors involving uterus, ovary and appendix. J Obstet Gynaecol Res. 2003 Aug;29(4):234–8.

15. Glover L, Frenslli FJ, Derrick FC Jr. Simultaneous adenomatoid tumors of epididymis and tunica vaginalis. Urology. 1973 Aug;2(2):192–5.