Pituitary metastasis unveiling a lung adenocarcinoma

Abstract

Summary Pituitary metastasis (PM) can be the initial presentation of an otherwise unknown malignancy. As PM has no clinical or radiological pathognomonic features, diagnosis is challenging. The authors describe the case of a symptomatic PM that revealed a primary lung adenocarcinoma. A 62-year-old woman with multiple sclerosis and no history of malignancy, incidentally presented with a diffusely enlarged and homogeneously enhancing pituitary gland associated with stalk enlargement. Clinical and biochemical evaluation revealed anterior hypopituitarism and diabetes insipidus. Hypophysitis was considered the most likely diagnosis. However, rapid visual deterioration and pituitary growth raised the suspicion of metastatic involvement. A search for systemic malignancy was performed, and CT revealed a lung mass, which proved to be a lung adenocarcinoma. Accordingly, the patient was started on immunotherapy. Resection of the pituitary lesion was performed, and histopathology analysis revealed metastatic lung adenocarcinoma. Following surgery, the patient underwent radiotherapy. More than 2 years after PM detection, the patient shows a clinically relevant response to antineoplastic therapy and no evidence of PM recurrence. Learning points Although rare, metastatic involvement of the pituitary gland has been reported with increasing frequency during the last decades. Pituitary metastasis can be the initial presentation of an otherwise unknown malignancy and should be considered in the differential diagnosis of pituitary lesions, irrespective of a history of malignancy. The sudden onset and rapid progression of visual or endocrine dysfunction from a pituitary lesion should strongly raise the suspicion of metastatic disease. MRI features of pituitary metastasis can overlap with those of other pituitary lesions, including hypophysitis; however, rapid pituitary growth is highly suggestive of metastatic disease. Survival after pituitary metastasis detection has improved over time, encouraging individualized interventions directed to metastasis to improve quality of life and increase survival.

Apoplexy in pituitary metastasis revealing a lung carcinoma

“…Even though PM tends to occur in patients with known metastatic cancer, symptomatic pituitary metastases may be the initial presentation of an unknown malignancy. 6 In a case series of 157 cases of PM in Japan, 10.8% detection of pituitary metastasis was initial to diagnosing the primary lesion. 7 Different reports found that most cases of PM preceding the diagnosis of malignancy originated from lung cancers, as is for our case.…”

“… 7 Different reports found that most cases of PM preceding the diagnosis of malignancy originated from lung cancers, as is for our case. 6 …”

“… 1 , 2 However, recent series suggest that the anterior pituitary is involved in more than 70% of cases. 6 Visual acuity and fields are frequently affected in PM. A review of 289 cases of PM found that visual dysfunction was the most common first manifestation, occurring in nearly half of the cases.…”

“…PM on pituitary MRI can appear as dumbbell‐shaped as the sellar diaphragm has not had time to stretch. 2 , 6 Other findings that suggest the diagnosis of PM are stalk enhancement with thickening, and loss of the posterior lobe bright spot but are not specific.…”

“…10 Lopes reinforces the importance of considering multimodal interventions directed at PM as it improves the survival of patients with PM. 6 …”