Primary squamous cell carcinoma of the endometrium in a woman of reproductive age: a rare case report

Case report: Clinicopathological characteristic of two cases of primary endometrial squamous cell carcinoma and review of the literature

Primary endometrial squamous cell carcinoma (PESCC) is a rare malignant tumor. To investigate the clinical and pathological features of PESCC, two cases of PESCC in Fujian Maternal and Child Health Hospital were retrospectively studied and the literatures were reviewed. Both of the two cases were menopausal women aged 57-62 years, clinically presenting with "vaginal discharge". Case 1 was a non-keratinising squamous cell carcinoma with high-risk HPV infection. Tumor infiltrated in deep myometrium with multifocal intravascular thrombus and macro metastases to one pelvic lymph node (1/15) and abdominal aortic lymph node (1/1). Lung metastasis occurred 36 months after the surgery. After surgical resection and without postoperative supplemental therapy, the patient remained tumor-free for 110 months to date. Case 2 had a history of breast cancer for 5 years and long-term intake of aromatase inhibitor drugs without HPV infection. It was a keratinized squamous cell carcinoma. Tumor also infiltrated in deep myometrium with multifocal intravascular thrombus and one pelvic lymph node metastasis (1/18), However, no metastasis was seen elsewhere. To date, the patient survived for 16 months without tumor after surgery. Both of the two cases expressed squamous epithelial markers P40, P63, and CK5/6, but neither expressed PAX8 or PR. Case 1 had diffuse expression of P16, wild-type P53, and ER-negative. Case 2 had negative P16, mutant P53, and focal positive ER. PESCC is often associated with HPV infection and low estrogen levels. However, studies in the literatures have found that P16 expression is not always consistent with HPV infection, indicating that PESCC cannot be easily classified as HPV-associated or non-dependent like cervical cancer. There are two main patterns of P16 and P53 expression, P16-positive/P53 wild-type and P16-negative/P53-mutant, but no positive expression of both has been seen so far. It is worth noting that we reported the second case of PESCC with a history of breast cancer, where the patient had been taking the oral aromatase inhibitor drug (exemestane) for a long period of time to reduce the estrogen level, indicating the low estrogen level may be also a key factor in the pathogenesis of PESCC.

Treatment of primary squamous cell carcinoma of the endometrium and review of previous literature: A case report

RATIONALE

Primary squamous cell carcinoma of the endometrium (PSCCE) has been occasionally reported. Treatment of this disease poses a challenge to clinicians because of its rarity. Herein, we report the case of a 56-year-old woman with typical clinical manifestations and a pathological diagnosis classified by molecular typing as having high microsatellite instability (MSI-H) PSCCE. Based on a review of the previous literature, we summarized the treatment options for this rare disease and proposed new opinions.

PATIENT CONCERNS

A 56-year-old woman was admitted to our hospital with irregular vaginal bleeding and lower abdominal swelling.

DIAGNOSIS

The patient was diagnosed with squamous cell carcinoma of the endometrium (stage IIIC1; MSI-H).

INTERVENTIONS

The patient underwent total abdominal hysterectomy, bilateral salpingo-ovariectomy (bso), and pelvic lymph node dissection. Following the surgery, the patient received adjuvant chemoradiotherapy.

OUTCOMES

The patient was followed up regularly. No recurrence or metastasis has been reported to date.

LESSONS

Curettage specimens may show only well-differentiated squamous epithelium, which is indistinguishable from normal squamous epithelium. It is difficult to infer from the histological morphology that the curettage specimens originate from the uterine cavity, which makes it difficult to diagnose PSCCE before the operation. We suggest that when an imaging examination indicates a tumor in the uterine cavity, even if multiple curettage specimens indicate normal or well-differentiated squamous epithelium, it indicates the possibility of PSCCE.

Molecular Analysis of HPV-independent Primary Endometrial Squamous Cell Carcinoma Reveals TP53 and CDKN2A Comutations : A Clinicopathologic Analysis With Re-evaluation of Diagnostic Criteria

Human papillomavirus (HPV)-independent primary endometrial squamous cell carcinoma (PESCC) is a rare but aggressive subtype of endometrial carcinoma for which little is known about the genomic characteristics. Traditional criteria have restricted the diagnosis of PESCC to cases without any cervical involvement. However, given that modern ancillary techniques can detect HPV and characteristic genetic alterations that should identify the more common mimics in the differential diagnosis, including endometrial endometrioid carcinoma with extensive squamous differentiation and HPV-associated primary cervical squamous cell carcinoma, those criteria may benefit from revision. To further characterize PESCC, we identified 5 cases of pure squamous cell carcinoma dominantly involving the endometrium that had the potential to be PESCC: 1 case involving only the endometrium and 4 cases with some involvement of the cervix. Clinicopathologic features were assessed and immunohistochemical analysis (p16, estrogen receptor, progesterone receptor, and p53), HPV RNA in situ hybridization (high-risk and low-risk cocktails and targeted probes for 16 and 18), and molecular studies were performed. All tumors showed aberrant/mutation-type p53 expression, were negative for estrogen receptor, progesterone receptor, and p16, and had no detectable HPV. Per whole-exome sequencing, 4 of the 5 tumors demonstrated comutations in TP53 and CDKN2A (p16). Four patients died of disease within 20 months (range, 1 to 20 mo; mean, 9 mo), and 1 patient had no evidence of disease at 38 months. PESCC represents a unique, clinically aggressive subtype of endometrial cancer with TP53 and CDKN2A comutations. This characteristic profile, which is similar to HPV-independent squamous cell carcinoma of the vulva, is distinct from endometrioid carcinoma with extensive squamous differentiation and HPV-associated primary cervical squamous cell carcinoma and can be used to distinguish PESCC from those mimics even when cervical involvement is present. Diagnostic criteria for PESCC should be relaxed to allow for cervical involvement when other pathologic features are consistent with, and ancillary techniques are supportive of classification as such.

PAX8 Positivity, Abnormal p53 Expression, and p16 Negativity in a Primary Endometrial Squamous Cell Carcinoma: A Case Report and Review of the Literature

Primary endometrial squamous cell carcinoma (PESCC) is a rare entity. As the clinicopathologic features and the immunophenotype have not been completely defined yet, here we report our experience and review of the literature on this topic. A 73-yr-old nulliparous woman presented with pelvic pain and vaginal bleeding. Endometrial biopsy showed a carcinoma with squamous differentiation infiltrating the myometrium. Total hysterectomy with bilateral salpingo-oophorectomy and selective pelvic lymphadenectomy was performed. Definitive diagnosis was squamous carcinoma of the endometrium, with one lymph node metastasis (stage IIIC1). Immunohistochemistry evidenced immunoreactivity of the tumor cells for cytokeratin 5, p63, cytokeratin 7, PAX8, PTEN, and cyclin D1, aberrant p53 overexpression, and Ki-67 reactivity in ~70% of the tumor cells. Estrogen and progesterone receptor, PAX2, WT1, and p16 were negative. Our case was the first PAX8-positive PESCC in the literature, underlining the Mullerian system origin of this neoplasm. Abnormal p53 expression of this case confirmed its role in the pathogenesis of PESCC. Further studies on a large number of cases are needed to better understand the pathologic features and the immunophenotype of PESCC.

Non-HPV-related verrucous carcinoma of the endometrium: report of one case and review of literature

The clinicopathologic diagnosis and treatment of a case of endometrial verrucous carcinoma were analyzed, combined with the relevant literature for review and discussion. The patient was a 67-year-old postmenopausal woman who had recurrent vaginal bleeding with increased secretion. The gross morphology and histopathology of the uterine cavity tumor had typical characteristic changes of verrucous carcinoma. There was obvious inflammation in the tumor background and squamous differentiation in the residual endometrial gland basal reserve cells. Tumor cell immunohistochemistry showed wild-type P53, P16 negative expression and HPV molecular test was negative. The expression of p63 was positive in squamous differentiated reserve cells, and Ki67 showed high proliferative activity. Verrucous carcinoma of endometrium is a rare tumor with low malignancy, that belongs to a special subtype of squamous cell carcinoma. It is easily missed or misdiagnosed and has a long diagnosis cycle. The diagnosis should be combined with clinical data, imaging and pathology. The pathogenesis of the disease is not clear. Surgical treatment is the first treatment, and the clinical prognosis is good.