# Clear Cell Adenocarcinoma Arising from Abdominal Wall Endometriosis

Authors: Thouraya Achach; Soumaya Rammeh; Amel Trabelsi; Rached Ltaief; Soumaya Ben Abdelkrim; Moncef Mokni; Sadok Korbi
Journal: Journal of Oncology
 (2008)

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## Abstract

Endometriosis is a frequent benign disorder. Malignancy arising in extraovarian endometriosis is a rare event. A 49-year-old woman is presented with a large painful abdominal wall mass. She underwent a myomectomy, 20 years before, for uterus leiomyoma. Computed tomography suggested that this was a desmoid tumor and she underwent surgery. Histological examination showed a clear cell adenocarcinoma associated with endometriosis foci. Pelvic ultrasound, computed tomography, and endometrial curettage did not show any malignancy or endometriosis in the uterus and ovaries. Adjuvant chemotherapy was recommended, but the patient was lost to follow up. Six months later, she returned with a recurrence of the abdominal wall mass. She was given chemotherapy and then she was reoperated.


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## Body

## 1. Introduction

Endometriosis  is a frequent benign  disorder. Several observations of the coexistence of endometriosis
and cancer have been published [1, 2]. Malignancy arising in extraovarian endometriosis
is a rare event [1]. Here, we report a case of clear cell adenocarcinoma
derived from pathologically confirmed endometriosis in the abdominal wall. We discuss the epidemiological and clinicopathological features of malignancy arising in abdominal wall endometriosis.


## 2. Case Report

A 49 year-old woman, gravida 3, para 0, underwent a myomectomy, 20 years before, for uterus
leiomyoma through a midline incision. She is presented with a painful large abdominal wall
mass. On physical examination, a firm indurated mass was palpated in the lower
abdominal wall. Abdominal and pelvic ultrasounds followed by computed tomography showed a
heterogeneous intramuscular mass of 8.5 cm diameter without local extension (Figure1). The clinical impression was of desmoid tumor and the patient taken to
surgery and the tumor was resected without rupture. The surgeon did not perform
any peritoneal washing or biopsies because of the absence of widespread tumor
in the peritoneal cavity. The surgical specimen consisted of 11 cm cutaneous and
muscular tissues, occupied by ill-defined white tumor, which contained cystic
cavities and abundant foci of necrosis. Surgical margins were positive.
Microscopically, the tumor showed a predominant papillary and tubulocystic
growth pattern (Figure 2). The tumor cells were round or polygonal most with
hobnail configuration (Figure 3). The cytoplasm was clear, and the nuclei were
round with prominent nucleoli. Cellular atypia was moderate, and mitosis was rare. Benign
endometriotic foci were observed in the proximity of the tumor (Figure 4). Immunohistochemically,
tumor cells showed diffuse and strong cytoplasmic positivity with vimentin,
epithelial membrane antigen, and cytokeratin 7, but no staining for cytokeratin
20 progesterone and estrogen receptor. Calretinin and mesothelin were negative.
Pelvic ultrasound and computed tomography identified normal-sized ovaries and
uterus. Endometrial curettage was negative for malignancy.Figure 1
Computed tomograms of the abdomen show a heterogeneous and ill-defined tumor
in the abdominal
wall.Figure 2
Tubulocystic and
papillary pattern (hematoxylin
eosin, original magnification ×200).Figure 3
Tumor
cells with hobnail configuration (hematoxylin eosin, original magnification  ×400).Figure 4
Endometrial gland invaded by tumor cells (hematoxylin eosin, original magnification
×400).The diagnosis  of
clear cell adenocarcinoma arising from abdominal endometriosis foci was
retained. Adjuvant chemotherapy was indicated, but the patient was lost to
follow up. She returned six months after. At that time, ultrasound and computed
tomography showed a recurrent mass at the abdominal wall with extension to the
bladder. Three cycles of combination chemotherapy with cyclophosphamide and cisplatin
were given, but the tumor did not regress. She underwent surgery again with a
resection of 5 cm encapsulated nodule. At that time, uterus, ovaries, and tubes
did not show any abnormalities. Histology demonstrated the same type of tumor.
Margins were free of tumor. Three cycles of chemotherapy were also given but
failed to control the disease; the chemotherapy she got is not precised. The
computed tomography showed again a recurrent mass with extension to the bladder
and pelvic bone, and adjuvant radiotherapy was indicated.


## 3. Discussion

Endometriosis,
defined as the presence of endometrial-like tissue outside the uterine cavity,
is usually located in the ovaries and pelvic peritoneum [2, 3]. Parietal
endometriosis is very rare and constitutes 1 to 2% of endometriosis cases [1].
It arises usually in a surgical scar of cesarean section or hysterectomy, and
less frequently in a surgical scar of hernia or of appendicectomy [1, 4]. Cases
of endometriosis without scar have been described [1]. The incidence of
abdominal wall endometriomas is of 0.04% among
parturients undergoing cesarean section and it is more frequent than
endometriosis following conventional gynaecologic surgery [4, 5]. In our case,
abdominal wall endometriosis occurred in a surgical midline scar of myomectomy.
The etiopathogenetic mechanism is more likely related to iatrogenic
transplantation of endometrium during gynecological surgery rather than hematogenous
dissemination or metaplasia [4, 6]. Clinical diagnosis remains difficult, and many
patients are asymptomatic [4]. Symptoms related to pelvic endometriosis are
noted in 26% of cases. Ultrasound can show a cystic lesion in many cases [5].
Women with pelvic endometriosis have a higher frequency of malignancy, but
malignant change in extrapelvic endometriosis is a rare event [1, 2, 4, 7].
Twenty percent of malignancy in endometriosis occurs in extragonadal site [1, 8, 9]. There is extensive clinicopathological, molecular, and genetic evidence
supporting the hypothesis that endometriosis is a neoplastic process with a
potential for malignant transformation [3]. The natural course of malignant
transformation of endometriosis is long and can be explained by estrogenic
stimulation [8, 10–12]. Malignant
transformation
in endometriosis was first described by Sympson in 1925 in
[9], who
proposed three criteria for diagnosis: demonstration of a clear example of the
endometriosis in proximity to the tumor, no other primary site for the tumor,
and histologic appearance consistent with an origin from endometriosis. Scott
in [1, 8] recommended the presence of transitional area between endometriosis and
cancer. Atypical endometriosis, a term first coined by LaGrenade and Silvergerg
in 1988 in [8, 13], is rare and is characterized by endometriotic glands with cytological
and/or architectural atypia (hyperchromatic or pale nuclei with moderate to marked
pleomorphism increased nuclear to cytoplasmic ratio, cellular crowding, stratification,
or tufting). The rate of atypical endometriosis ranges from 1.7 to 3.6% in ovarian endometriosis
[13]. Fukunaga et al. [13] demonstrated that atypical endometriosis in ovary is
often associated with epithelial neoplasm and showed direct transition from
atypical epithelium to malignant tumor. In our case, the criteria of Sympson
were fully satisfied. The demonstration of endometriosis might require the
examination of multiple levels and sections, that is why preoperative biopsy cannot
make the diagnosis of malignancy arising in endometriosis [6]. Tumors that can
arise in endometriosis include in decreasing order: endometrio id carcinoma
(75.9–69.1%), sarcoma
(25–11.6%), clear
cell carcinoma (13.5–4.5%), and
mucinous or serous carcinoma (4.6%–1%) [4]. In
extrapelvic localization, clear cell carcinoma is the most common histological
subtype, followed by endometrioid carcinoma [1]. Due to the rarity of malignant
transformation of endometriosis at extragonadal sites, it is difficult to
establish a treatment protocol. First-line treatment is surgery, removing as
much endometriosis as possible, staging at this point is also necessary.
Second-line treatment, with chemotherapy, radiotherapy, and even hormonotherapy
may be needed. Prognosis is variable from 10 to 100% five-year survival,
depending on histological type and localization of the disease [7].


## 4. Conclusion

Cutaneous
localization of endometriosis is unusual and appears most frequently in
surgical scars from obstetric or gynecological interventions. It is important
to recognize the possibility of tumors arising from endometriosis when the
pathologist is confronted to an extraovarian tumor with endometrial appearance.
Examination of multiple sections is required to demonstrate endometriosis foci.



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