Introduction/Background*Endometrioid carcinoma arising in adenomyosis (EC-AIA) is a rare entity. We present a case of an advanced stage presenting with deep vein thrombosis (DVT) and visual impairment.

Methodology 42-year old patient presented to our institution, due to DVT of left femoral vein. During hospitalisation, an abdominal ultrasound showed a uterine tumour, resembling a myoma. Increased Ca 125 and Ca 15-3 were observed. No subsequent diagnostic procedures were performed, a follow up visit with personal gynaecologist was recommended. In the following weeks, she noticed visual impairment and trouble with understanding. Cranial MRI showed metastatic lesions and possible meningeal carcinosis. Patient was readmitted. Abdominal computer tomography (CT) showed a pelvic necrotic formation between right ovary and uterus, with pathologic iliac and paraaortic lymph nodes. Multidisciplinary team indicated primary debulking surgery. Before the procedure, she underwent coloscopy and gastroscopy without pathologic findings.

Median laparotomy with hysterectomy, omentectomy, appendectomy and debulking of pelvic and paraaortic lymph nodes were performed. Pathohistological report showed a necrotic tumour, originating in the myometrium on the right lateral side of the uterus and infiltrating the right salpinx and ovary. Microscopic evaluation revealed endometrioid adenocarcinoma, grade 1, originating in myometrium, without involvement of endometrium. Positive right obturator and paraaortic lymph nodes did not involve the capsule. Immunohistochemistry showed positive oestrogen and progesterone receptors and p53-wt expression. Additional genetic analysis was done, due to loss of MSH6 protein. Due to probable cranial involvement, stage was set as FIGO IVB. Subsequent treatment consisted of palliative radiotherapy of the cranium, followed by introduction of letrozole as maintenance therapy. Follow up imaging studies showed no signs of disease progression. At the last check up, the patient was in good condition, without specific complaints.

Conclusion*Mechanism of EC-AIA is not well understood. As in our case, the tumour can mimic benign uterine lesions and postpone a proper diagnosis. This can lead to advanced stage disease with uncommon clinical presentation. Few studies have described the molecular mechanism of adenomyosis formation. It has been suggested that loss of heterozygosity in the DNA mismatch repair family is associated with adenomyosis and its pathogenesis. Better understanding of the molecular and immunologic drivers of response and resistance will be critical in management of EC-AIA.