Year : 2008 | Volume
: 51 | Issue : 2 | Page : 267--268
Primary endometrial squamous cell carcinoma with extensive squamous metaplasia and dysplasia
Permeet Kaur Bagga, TS Jaswal, Usha Datta, NC Mahajan
Department of Pathology, M.M. Institute of Medical Sciences and Research, Mullana-Ambala, India
Permeet Kaur Bagga
136-D, Calibre Plaza, AC Market, Bhadaur House, Ludhiana, Punjab
Primary squamous cell carcinoma of endometrium is a rare entity. Only 64 cases have been documented in the literature. We report a case of 60-year-old postmenopausal woman who presented with abdominal distention and blood-stained vaginal discharge for 6-7 months. Clinically, chronic pyometra was considered. Total abdominal hysterectomy was performed and histopathologically, it was diagnosed as a case of primary squamous cell carcinoma of endometrium with extensive squamous metaplasia and dysplasia.
|How to cite this article:|
Bagga PK, Jaswal T S, Datta U, Mahajan N C. Primary endometrial squamous cell carcinoma with extensive squamous metaplasia and dysplasia.Indian J Pathol Microbiol 2008;51:267-268
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Bagga PK, Jaswal T S, Datta U, Mahajan N C. Primary endometrial squamous cell carcinoma with extensive squamous metaplasia and dysplasia. Indian J Pathol Microbiol [serial online] 2008 [cited 2019 Nov 13 ];51:267-268
Available from: http://www.ijpmonline.org/text.asp?2008/51/2/267/41686
Squamous cell carcinoma develops in the endometrium but is extremely rare. Only 64 cases of primary squamous cell carcinoma have been documented in the literature.  It is usually seen in postmenopausal women and is strongly associated with cervical stenosis, pyometra, chronic inflammation, nulliparity and icthyosis uteri.
A 60-year-old multiparous, postmenopausal woman presented with the history of mass abdomen for last 6-7 months, which was progressively increasing in size. The patient was diagnosed and treated for CIN grade-III 5 years back by pap smear examination, colposcopy and cervical conization procedure. No invasive carcinoma was identified in the cervix. On recent clinical examination, an abdominal mass of 28 weeks size was palpable in the hypogastric region. Per-speculum examination showed an atrophied cervix. No cervical os could be located. On per-vaginal examination, a midline mass about 28 weeks size was felt; cervix was found to be atrophied. On ultrasonography, uterine cavity was enlarged and distended with fluid. Impression given was of pyometra or haematometra. Cervix could not be visualized. Preoperatively, other laboratory tests were within normal limits. Clinically, a diagnosis of pyometra was made. A total abdominal hysterectomy was performed.
Panhysterectomy specimen was received. The uterus was found to be enlarged to a size measuring 13 cm × 12 cm × 05 cm. Uterine cavity was markedly distended and filled with purulent material. No cervix could be identified grossly. The inner surface of uterine cavity was irregularly folded and dilated.
Sections examined from different parts of the endometrial cavity and corpus uteri revealed extensive replacement of the entire endometrial lining by squamous epithelium with areas of dysplasia and carcinoma in situ [Figure 1] and invasive keratinizing squamous cell carcinoma extending into myometrium [Figure 2]. Distinct transition from metaplastic to dysplastic, in situ and invasive carcinoma was observed. No normal endometrial glandular epithelium was seen. There was no cervical lesion continuous with that of uterus. The diagnosis of primary squamous cell carcinoma of endometrium was made.
Endometrial squamous cell carcinoma is extremely rare, with only 64 cases being reported in the literature. In 1996, Goodman et al. reported eight cases of endometrial squamous cell carcinoma and reviewed previously reported 56 cases of it.  In a population-based study from Norway, the prevalence was 0.1%. 
The presence of squamous epithelium in the endometrium, variously termed ichthyosis uteri (a condition in which endometrium is replaced by keratinized squamous epithelium), leukoplakia epidermidization, psoriasis uteri, epidermoid heteroplasia, cholesteometra and indirect regenerative squamous metaplasia, has been described under a variety of conditions and is benign in the majority of cases. Invasive squamous cell carcinoma of the endometrium is rare and is thought to arise by one of the two mechanisms: upward spread of a primary cervical lesion or transformation of reserve or stem cells positioned between the glandular basement membrane and the endometrial columnar epithelium. Invasive squamous cell carcinoma as a result of upward spread from the cervix is very unlikely if the cervical lesion is intramucosal. In the present case, only CIN grade-III was identified in the cervix for which, the patient was already treated.
To be accepted as a primary carcinoma of the endometrium, the tumor must satisfy the criteria established by Fluhmann and modified by Kay:  there must be no coexisting endometrial adenocarcinoma; there must be no connection between endometrial tumor and squamous epithelium of cervix; there must be no primary squamous carcinoma of cervix; and if cervix shows an in situ carcinoma, there must be no connection between this and independent endometrial neoplasm. Our patient satisfies these criteria. The origin of such neoplasm is unclear. Many favor a sequence of change with squamous metaplasia progressing through dysplasia to invasive carcinoma.  The present case demonstrated extensive squamous metaplasia with dysplasia, carcinoma in situ and multifocal invasive squamous carcinoma, providing further support for this proposed sequence. The transition from squamous metaplasia through dysplasia to frank invasive squamous cell carcinoma as observed in the present case is itself supportive of it being primary tumor of corpus uteri since extension of a uterine cervical carcinoma to corpus will not show such metaplastic and dysplastic changes.
Endometrial squamous cell carcinoma usually occurs in postmenopausal women with mean age of presentation being 67 years. There is a strong association with cervical stenosis, pyometra, chronic inflammation and nulliparity. It is believed that tumor may arise from ichthyosis uteri - a condition in which the endometrium is replaced by keratinized squamous epithelium.  In the present case too, the patient was a postmenopausal woman who was clinically diagnosed to be having pyometra; this was obvious grossly and on histopathological examination, ichthyosis uteri was present.
In endometrial carcinoma, the presence of a malignant squamous cell component worsens the prognosis. The prognosis of squamous cell carcinoma is related to the stage at diagnosis. In a review of reported cases, 80% of stage I patients survived whereas survival for patients with stage III disease was only 20%.  No final treatment recommendation has been given so far; therapy usually consists of surgical hysterectomy with adnexectomy and radiotherapy in some cases. Although rare, diagnosis of primary squamous cell carcinoma of endometrium should be considered in a postmenopausal elderly female presenting with pyometra and cervical stenosis.
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