Cerebral endometriosis

Case report

Full access

✓ A 20-year-old woman presented with a 3-year history of intermittent focal headaches and a generalized seizure. Computerized tomography demonstrated a hypodense ring-enhancing cystic right parietal lobe lesion. At operation, a chocolate-colored cyst was excised which on histological examination proved to be endometriosis.

Endometriosis is a condition in which functional endometrial tissue is located at extrauterine sites. It is most commonly seen in the pelvis and is rarely found in the abdominal cavity above the umbilicus. Endometrial tissue has been found in the thorax, the extremities, the vertebral column, the spinal canal, and the sciatic nerve.2–7 A case of cerebral endometriosis is presented.

Case Report

This 20-year-old woman was admitted to the Yale-New Haven Hospital because of a generalized seizure that had been preceded by a severe right occipital headache. She gave a 3-year history of episodic, pulsatile right occipital headaches that characteristically lasted 4 to 5 minutes and occurred once or twice each month. These headaches usually developed in the evening and were unrelated to menstrual cycle phase, activity, or diet. She denied any history of seizures, migraine headaches, other neurological symptoms, drug abuse, trauma, recent illness, or infections. Her menstrual history was normal. Her medical history was relevant only for two therapeutic abortions, one at 16 and one at 17 years of age. She took no prescribed medications and had not previously been hospitalized. A detailed review of systems was otherwise negative. Her family history was negative for migraine headaches, seizures, or other neurological or gynecological disorders.


At the time of admission, the patient's neurological, gynecological, and general physical examinations were normal. Laboratory studies of blood and urine, an electrocardiogram, and chest x-ray films were normal. An electroencephalogram revealed moderate generalized slowing, most prominent over the right temporal area. Computerized tomography (CT) with and without intravenous contrast medium demonstrated a hypodense ring-enhancing well-circumscribed lesion, located peripherally in the right posteroinferior parietal region. There was no significant mass effect or edema. A CT scan using bone windows and plain radiographs of the skull revealed scalloping of the adjacent calvaria. Cerebral angiography demonstrated an avascular parietal lobe mass. Preoperatively, the patient was given phenytoin and remained neurologically normal without additional seizures.


The patient underwent a right parietooccipital craniotomy. Calvarial thinning was noted over the lesion. When the dura was opened, a greenish-brown cystic lesion was seen on the surface of the posteroinferior parietal lobe. Aspiration of the cyst yielded thick chocolate-brown fluid with no odor. The cyst walls were smooth and hemosiderin-stained except for a 5-mm reddish-brown nodule. The entire cystic lesion was excised.

Postoperative Course

The patient tolerated the procedure well, and had an uneventful postoperative course without neurological deficit. She was treated with danazol, 400 mg twice daily for 6 months. She has had no subsequent seizures or menstrual irregularity and her neurological and gynecological examinations were normal 1 year after her operation.

Pathological Examination

Histological evaluation of the lesion showed endometrial epithelium and hemorrhagic endometrial stroma (Fig. 1). The epithelial cells were cuboidal and had dark pyknotic nuclei and abundant cytoplasm. The stroma was composed of spindle-shaped cells and contained variable amounts of pigmented macrophages. The lining mucosa was focally denuded and replaced by iron-laden macrophages interspersed in endometrial stroma. Mature brain showing reactive gliosis was seen adjacent to the lesion. The pathological diagnosis was benign endometriosis.

Fig. 1.
Fig. 1.

Low-power photomicrograph showing endometrial epithelium and hemorrhagic endometrial stroma with adjacent brain tissue containing scattered reactive gemistocytic astrocytes. H & E, × 150.


It is of interest that, despite the histological evidence of endometrial tissue, there were no symptoms relating to the patient's menstrual cycle. Hematogenous implantation would seem to be the most likely pathogenic mechanism. The history of two therapeutic abortions and the absence of demonstrable endometriosis at other sites suggests that endometrial cells spread hematogenously to the brain through the vertebral venous system,1 an undetected partially patent foramen ovale, or a pulmonary arteriovenous shunt.


The authors wish to thank Dr. Jung H. Kim and D. J. Mulqueen for their help in preparing this report.


Article Information

Address reprint requests to: Lee L. Thibodeau, M.D., Section of Neurosurgery, Department of Surgery, Yale University School of Medicine, 333 Cedar Street, New Haven, Connecticut, 06510.

© AANS, except where prohibited by US copyright law."



  • View in gallery

    Low-power photomicrograph showing endometrial epithelium and hemorrhagic endometrial stroma with adjacent brain tissue containing scattered reactive gemistocytic astrocytes. H & E, × 150.



Batson OV: The function of the vertebral veins and their role in the spread of metastases. Ann Surg 112:1381491940Batson OV: The function of the vertebral veins and their role in the spread of metastases. Ann Surg 112:


Blaustein A: Pelvic endometriosisBlaustein A (ed): Pathology of the Female Genital Tracted 2. New York: Springer-Verlag1982464478


Duncan CPitney WR: Endometrial tumours in the extremities. Med J Aust 2:7157171949Med J Aust 2:


Head HBWelch JSMussey Eet al: Cyclic sciatica. Report of case with introduction of a new surgical sign. JAMA 180:5215241962JAMA 180:


Lombardo LMateos JHBarroeta FF: Subarachnoid hemorrhage due to endometriosis of the spinal canal. Neurology 18:4234261968Neurology 18:


Novak ER: Pathology of endometriosis. Clin Obstet Gynecol 3:4134281960Novak ER: Pathology of endometriosis. Clin Obstet Gynecol 3:


Stern HToole ALMerino M: Catamenial pneumothorax. Chest 78:4804821980Chest 78:




All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 43 43 43
PDF Downloads 41 41 41
EPUB Downloads 0 0 0


Google Scholar