Dedifferentiated endometrioid adenocarcinoma: An under-recognized but aggressive tumor?
A 62-year-old postmenopausal woman presented to the emergency room after a fall that resulted in acute exacerbation of right shoulder pain. She first noticed this pain three weeks prior, but could not identify any inciting factors. In the emergency room, an X-ray was obtained that showed a proximal humeral facture with lytic lesions in the surrounding bone (). She was placed in a sling and discharged with outpatient follow-up. As part of her workup, a computed tomography (CT) scan of the chest, abdomen, and pelvis was obtained and revealed multiple pulmonary nodules, necrotic-appearing mediastinal and hilar lymph nodes, a left adrenal nodule, a mass within the T10 vertebral body with epidural extension and spinal cord compression, and multiple bony lytic lesions. Bony lesions were noted throughout the T1 and T10 vertebral bodies, left ileum, right ileum, left femoral head, and left acetabulum. The pelvis was notable for a fibroid uterus, but was otherwise unremarkable. There was no pelvic lymphadenopathy or ascites.\nOne week later, she presented to the emergency room with rapid onset of lower extremity weakness. She was admitted with a diagnosis of spinal compression and initiated on dexamethasone to prevent further neurologic compromise. Magnetic resonance imaging (MRI) demonstrated a large T11 lesion with extensive epidural extension, a T2 lesion expanding into the prevertebral and ventral epidural space, and numerous other lesions throughout her spinal column (). Neurosurgery took her to the operating room for decompression and performed a T10–T12 laminectomy, tumor resection with T11 vertebrectomy, T9–L1 fusion and reconstruction with titanium cage and bone matrix allograft.\nThe pathology specimen showed a poorly differentiated adenocarcinoma. It was strongly positive for estrogen receptors, progesterone receptors, and Pax 8, suggesting an endometrial or breast cancer. On further interview, the patient reported five months of intermittent vaginal bleeding and a left breast mass. Bilateral mammography was negative. Pelvic ultrasound revealed fibroids with poor visualization of the endometrial lining. Pathology from dilation and curettage was notable for a well-differentiated endometrioid carcinoma and an associated undifferentiated carcinoma, suggesting dedifferentiated endometrioid adenocarcinoma (). Histopathological and immunostaining features of the dedifferentiated uterine carcinoma were similar to those in the specimen from T11. CA-125 was elevated to 264.\nTwo weeks after her initial surgery, she began radiation therapy. Over the course of two weeks, she received 3000 cGy of radiation therapy in 10 fractions to C5–T2 and the right humerus. Due to inadequate healing at the site of spinal fusion, radiation therapy to T10–T12 was deferred until six weeks after her initial surgery, after which she received another 3,000 cGy in 10 fractions. She remained wheelchair bound and her Gynecological Oncology Group performance status was estimated to be 3–4. This precluded her from chemotherapy and she was therefore started on a regimen of megace alternating with tamoxifen (). Due to leukocytosis and deep venous thromboses, she was readmitted to the hospital 6 weeks after initiating hormonal therapy. Imaging studies showed progression of disease, including a new compression of the T2 vertebral body and widespread nodal and pulmonary metastatic disease. CA-125 had risen from 264 to 789. The patient and her family elected to discontinue treatment and transfer to home hospice given the rapid progression of disease.