A Case of Langerhans Cell Histiocytosis Manifested as a Suprasellar Mass

Abstract

Langerhans cell histiocytosis (LCH) has diverse clinical manifestations, including intracranial mass lesions. We report a case of LCH that manifested as a suprasellar mass, and initially misdiagnosed as a germ cell tumor. A 29-year-old woman presented with polyuria, polydipsia and amenorrhea. Laboratory findings revealed hypopituitarism with central diabetes insipidus, and a suprasellar mass and a pineal mass were observed on magnetic resonance imaging. Under the clinical impression of a germ cell tumor, the patient was treated with germ cell tumor chemotherapy (cisplatin and etoposide) and radiation therapy without biopsy. After initial shrinkage of the lesions, further growth of the tumor was observed and a biopsy was performed. The histopathology revealed LCH. After chemotherapy according to the LCH III protocol, the tumor disappeared. She is on regular follow up for 5 years without relapse. The present findings indicate that LCH should be included in the differential diagnosis of a suprasellar mass, even in adults, especially when it manifests with diabetes insipidus. This case also underscores the importance of a histopathologic diagnosis in patients with suprasellar tumors before the initiation of a specific therapy, even if the clinical findings are highly suggestive of a specific diagnosis.

Keywords: Central nervous system neoplasms; Diabetes insipidus; Germinoma; Langerhans cell histiocytosis; Sella turcica.

Fig. 1. Sagittal, T1-weighted images. A: Initial MRI on June 2007. Well enhanced mass with a diameter of 2.3 cm is observed around the pituitary stalk (white arrow). Another 1 cm-sized rim-enhancing lesion is observed in the pineal gland (black arrow). B: MRI on September 2007. After 3 cycles of germ cell tumor chemotherapy, mass size decreased markedly, showing only linear enhancement. C: MRI on September 2008. Increased size of enhancing mass in pituitary stalk and hypophysis areas observed (white arrow). D: MRI on December 2008. After Langerhans cell histiocytosis initial chemotherapy. Significant reduction in tumor size is observed. E: MRI on May 2015. Subtle residual enhancement in 3rd ventricle floor is observed. No other abnormal enhancing lesion is observed. Pituitary gland and stalk shows atrophy.

Fig. 2. Photograph of the surgical specimen. A: Many lymphohistiocytic infiltrations are noted in the low power view (HE staining, ×100). B: Scattered Langerhans cells are seen, with eosinophils and lymphocytes (HE staining, ×400). C and D: Immunohistochemical staining shows strong CD1 positivity (C) and weak S-100 positivity (D). HE, hematoxylin and eosin.