RMS is the most common soft-tissue tumor of childhood, and responsible for approximately one-half of all soft-tissue sarcomas in this age group [
5,
6]. However, they are rare, representing only 3 to 4 percent of pediatric cancers overall. Approximately 350 new cases are diagnosed in the US each year, and the annual incidence in children, adolescents, and young adults under the age of 20 is 4.3 cases per one million population [
5]. Lung is the most frequent site of metastases from rhabdomyosarcoma. Other sites of distant metastatic involvement include bone marrow (approximately 30 percent), bone (30 percent); omentum/ascites (16 percent), and pleura (13 percent); visceral involvement and brain metastases are rare [
7‐
10]. To the best of our knowledge, a pituitary metastasis from rhabdomyosarcoma has never been reported in the literature. In the widest review of literature about pituitary metastases including 380 patients, none of them had a RMS as the primary localization [
11]. These data confirm the authenticity of our report. The incidence of pituitary metastases on autopsy is between 1 and 3.6 percent [
12,
13], and if the parasellar region is included the incidence rises up to 27 percent [
14]. Breast and lung carcinoma are the two most common forms of malignant tumor that metastasize to the pituitary gland. The most common symptom seems to be diabetes insipidus [
15,
16], reflecting a predominance of metastasis to the posterior lobe. Bilateral hemianopia is the most common type of visual field impairment [
17]. Infiltration of the adjacent cavernous sinus usually induces cranial nerve III palsy, or less frequently, nerve IV palsy. Compression of nerve VI is relatively uncommon because it is well sheltered within the cavernous sinus [
18]. Facial numbness due to cranial nerve V dysfunction is also rare [
18]. Tumor extension to the septum pellucidum or the frontal lobes may result in cognitive deficit or psychiatric symptoms, and in anosmia if cranial nerve I is affected [
16,
18]. Stretching of the diaphragma sellae or ventricular distention can give rise to headaches or intracranial hypertension. All these symptoms, except for diabetes insipidus, are common in pituitary adenomas. The question is how to differentiate pituitary metastasis from pituitary adenoma in patients with a history of malignant disease, but also in those in which pituitary metastasis is the initial symptom of a malignant disease. Clinically, the presence of diabetes insipidus is very suggestive of pituitary metastasis and can be the first manifestation of a malignant neoplasm [
19]. Although history or coexistence of malignancy usually leads to the diagnosis, it is of limited diagnostic value because 1.8 to 16 percent of patients with known malignancy and a sellar tumor turn out to harbor a pituitary adenoma [
17,
20]. With regard to neuroimaging findings, sensitive and specific criteria for differentiating pituitary metastases from pituitary adenomas have not been reported and radiological evaluation generally has not been fruitful [
21], unless other metastatic brain lesions coexist. A few imaging characteristics have been reported to be helpful in differentiating pituitary metastases from pituitary adenomas; these include the following: 1) thickening of the pituitary stalk; [
17,
22] 2) loss of a high-intensity signal from the posterior pituitary; [
23] 3) isointensity on both T1- and T2-weighted magnetic resonance images; [
22] 4) invasion of the cavernous sinus; [
22] and 5) sclerotic changes around the sella turcica [
24]. Although these findings may indicate the possibility of metastases, they are in no way specific for pituitary metastases [
2].