Pituitary gland involvement by a gamma delta hepatosplenic lymphoma, a mimicker of pituitary adenoma: report of a rare case

Pituitary Infiltration by Lymphoma

Lymphoma infiltration to the pituitary is rare. It represents less than 0.5% of all reported pituitary metastases (PMs). Here we present a case series of 3 patients with PMs from a systemic lymphoma. Also, we performed a literature review of the cases reported. We identified additional 31 cases in which non-Hodgkin lymphoma (NHL) was the most common (n = 28, 90%), with large B-cell NHL the most frequent histological subtype (n = 14, 45%). Central hypothyroidism (n = 21, 67%) was the most frequent pituitary deficiency followed by adrenal insufficiency (n = 19, 61%) and diabetes insipidus (DI; n = 18, 58%). Full endocrine recovery was found in only 12% (n = 4) of patients after treatment, and magnetic resonance imaging showed tumor regression in 22% of them. In our series, 2 patients were diagnosed with diffuse large B-cell lymphoma, and 1 had mixed cellularity of classic Hodgkin lymphoma. The mean age was 54 ± 6.92 years. Hypopituitarism and DI were present in all of them, with 100% of mortality because of advanced systemic disease.

Malignant lymphoma in the parasellar region

The entity of pituitary (sellar or parasellar) lymphoma includes primary pituitary lymphoma (PPL) and secondary pituitary lymphoma (SPL). The latter has an involvement of systemic lymphoma. Both of these lymphomas are extremely rare. We describe a patient with SPL showing a good prognosis. A 78-year-old woman presented with diplopia, left ptosis, and back pain. Magnetic resonance (MR) imaging revealed a parasellar mass lesion extending to the upper clivus and another mass lesion with compression fracture of the Th3 vertebral body. Transsphenoidal exploration was performed, and it showed diffuse large B-cell lymphoma. Based on the positive tumor cells in the following bone marrow aspiration and hepatosplenomegaly in computed tomography (CT) findings, this patient was diagnosed as having a pituitary involvement of systemic lymphoma. After chemotherapy, she achieved complete remission for 4 years. The entity of pituitary lymphoma is extremely rare. Nineteen cases of PPL and 16 cases of SPL have been reported. Generally, clinical and radiological diagnosis was difficult because there are no specific findings. Therefore, biopsy was necessary in all of the cases. T2 hypointensity of a lesion in MR imaging in addition to an elevated serum level of soluble interleukin-2 receptor (sIL-2R) in a patient with a sellar lesion can be useful clues for the differential diagnosis of this rare disease.

Hepatosplenic T-cell lymphoma and inflammatory bowel disease

OBJECTIVE

This article reviews the current literature and knowledge about hepatosplenic T-cell lymphoma (HSTCL), providing an overview of the clinical features, a description of its pathology and immunophenotypic traits in relation to other lymphomas. In addition, we explore the history of reported cases of hepatosplenic T-cell lymphoma in relation to the possible existence of a causal relationship between infliximab use and HSTCL. The treatments for HSTCL will be briefly addressed.

METHODS

A comprehensive literature search using multiple databases was performed. Keyword search phrases including "lymphoma," "hepatosplenic T-cell lymphoma," "Inflammatory bowel disease," "6-mercaptopurine," and "infliximab" were used in various combinations. In addition references from published papers were reviewed as well.

RESULTS

There are over 200 reported cases of HSTCL. Only 22 cases of hepatosplenic T-cell lymphoma are associated with IBD treatment. Clinicians usually reserve immunomodulators and biologics for moderate to severe IBD cases. The ultimate goal of therapy is to control inflammation and therefore allow mucosal healing. IBD patients demonstrating mucosal healing are less likely to undergo surgery and experience complications related to their disease. We manipulate the immune system with corticosteroids, immunomodulators, and biologics, therefore causing bone marrow suppression. With bone marrow suppression, malignant degeneration may begin through selective uncontrolled cell proliferation, initiating HSTCL development in the genetically susceptible.

CONCLUSION

Hepatosplenic T-cell lymphoma is a rare disease, often with a poor outcome. With the increasing number of reported cases of HSTCL linked to the use of infliximab, adalimumab, and AZA/6-MP, there appears to be an undeniable association of HSTCL development with the use of these agents. This risk is unquantifiable. When considering the rarity of cases and the multiple complications with uncontrolled disease, however, the benefit of treatment far outweighs the risk.