Contributed by Mônica R. Gadelha1, Leonardo Vieira Neto*1,2, Juliana Malheiros Giorgetta1, Paulo José da Mata Pereira3, Paulo Niemeyer Filho3, Leila Chimelli4 *The first two authors have contributed equally to this manuscript.
Endocrinology1 and Pathology4 Divisions, University Hospital, Federal University of Rio de Janeiro; Endocrinology Division2, Lagoa Federal Hospital; Neurosurgery Division3, Santa Casa de Misericórdia, Rio de Janeiro, Brazil.
CLINICAL HISTORY AND IMAGING STUDIES
A 21-year-old female patient, without previous co-morbidities, presented with progressive decrease in visual acuity in the right eye, ipsilateral ptosis, frontal headache and bilateral galactorrhea on expression in the last seven months before the consultation. At that time, in another institution, a serum prolactin level, which was 74.9 ng/mL [normal range (NR): 5 - 25], and a sella turcica magnetic resonance imaging (MRI) were requested. The MRI (Figures 1, 2, 3 and 4) revealed an expansive solid lesion, isointense in T1- and T2-weighted sequences with gadolinium enhancement measuring 3.5x3.3x4.2 cm, with its epicenter in the sella turcica. It extends superiorly reaching the optic chiasm, laterally mainly to the right cavernous sinus and inferiorly towards the sellar floor, causing erosion of the sellar floor and the adjacent area of the clivus. She was treated with bromocriptine 2.5 mg/day for two months.
The patient was then referred to the endocrine unit with the diagnosis of a pituitary macroadenoma. She denied alterations in the menstrual cycle pattern, polyuria or polydispsia and there were no signs or symptoms of acromegaly or Cushing's syndrome. Peripheral visual field testing (manual Goldmann perimetry) showed no visual field defect. At baseline pituitary function evaluation, the patient had hyperprolactinemia due to stalk compression (prolactin 66.4 ng/mL and diluted 1:100 prolactin 63.5 ng/mL), LH: 2.35 mUI/mL, FSH: 8.89 mUI/mL, alpha-subunit of glycoprotein pituitary hormones: 57 ng/L (80 - 604), TSH: 3.11 µUI/mL (NR: 0.3 - 0.5), free T4: 1.1 ng/dL (NR: 0.8 - 1.9), GH: 0.37 ng/mL, IGF-I: 174 ng/mL (NR for patient´s age: 116 - 341), and cortisol: 18.5 µg/dL. The patient underwent transsphenoidal surgery and the tumor showed to be invasive, occupying the sphenoid sinus and destroying the sellar floor. During the procedure, the tumor was found to be hard with a high blood vessel density. In fact, due to important bleeding during the excision, it was incompletely resected. Currently, the patient has galactorrhea, amenorrhea, blurred vision in right eye and mild frontal headache. Postoperative laboratory tests were similar to the preoperative ones.
Histopathological examination of the surgically excised tissue revealed a heterogeneous lesion, consisting predominantly of multinucleated giant cells of various sizes (Figures 5 and 6) most of them containing numerous nuclei. Mononuclear spindle or oval stromal cells were also observed among the multinucleated giant cells, although in focal areas the lesion was composed predominantly of spindle shaped stromal cells assuming a fascicular pattern (Figure 7). There were also thin reactive bone trabeculae, as seen in Figure 8. The lesion was highly vascularized, as demonstrated by the presence of numerous thin congested blood vessels. What is your diagnosis?