Abstract
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.