Spindle cell oncocytoma of the pituitary and pituicytoma: Two tumors mimicking pituitary adenoma.

BACKGROUND: Spindle cell oncocytoma (SCO) and pituicytoma are rare nonfunctioning tumors of the pituitary. Both tumors are low grade and macroscopically indistinguishable from a nonfunctioning pituitary adenoma.We report one case of SCO and one case of pituicytoma and review the previous literature. CASE DESCRIPTION: One patient was a 39-year-old man who presented with progressive headache, visual blurring, and polyuria of 3-year duration. He underwent partial resection (30% of the tumor) and postoperative adjuvant radiation therapy. Histopathology revealed SCO. However, after 9 months, the residual tumor grew and partial resection (70% of the tumor) was performed again. Four months after the second surgery, the tumor recurred again and he underwent transsphenoidal resection of the tumor with stable residual tumor to date. The other patient was a 59-year-old man who presented with a 3-month history of visual decline, fatigue, difficulty in writing, and polyuria. He underwent transsphenoidal resection (total) of the tumor. Histopathology revealed pituicytoma. He has been stable without evidence of recurrence for 1 year and 4 months. CONCLUSION: To date, there are 15 reported cases of SCO and 45 reported cases of pituicytoma including our cases. An incomplete resection of the tumor was a significant risk factor for recurrence in both SCO and pituicytoma (P = 0.0014 and P = 0.019, respectively). These tumors have a tendency to be hypervascular, which may hamper total resection. Epithelial membrane antigen (EMA) and mitochondria positivity is characteristic to SCO and they are considered to be important immunomarkers to distinguish these tumors.

Neurocytoma of the cerebellum.

BACKGROUND: Neurocytomas are benign central nervous system tumor composed of small cells with characteristics of neuronal differentiation; they are usually located in the supratentorial periventricular region, in close relation to the septum pellucidum and the foramen of Monro. CASE DESCRIPTION: Herein we report a rare case of a neurocytoma located in the cerebellar hemisphere. To date there are only four such reported cases. CONCLUSION: Neurocytomas should be considered in the differential diagnosis of mass lesions in the cerebellum.

Primary CNS lymphoma with bilateral symmetric hypothalamic lesions presenting with panhypopituitarism and diabetes insipidus.

We present an unusual case of primary central nervous system (CNS) lymphoma presenting with bilateral symmetric hypothalamic lesions causing diabetes insipidus and hypopituitarism. A 50-year-old male presented initially with mental status changes, polyuria and polydipsia. The patient was determined to have diabetes insipidus (DI) and significant anterior pituitary deficiencies resulting in symptomatic pleural and pericardial effusions. Brain MRI with contrast demonstrated bilateral enhancement of his hypothalamus extending to the optic tract. The extensive diagnostic workup that ensued on his initial presentation was non-diagnostic as he had no obvious site of involvement that was easily accessible to biopsy. With close follow-up, the patient had rapid radiographic progression of his disease to his cerebral hemispheres. He therefore underwent brain biopsy and was diagnosed with primary CNS large B cell lymphoma. Chemotherapy has resulted in disease remission with resolution of MRI findings, but the patient has not had resolution of the hypopituitarism or DI. This case highlights the unique diagnostic challenge of patients with isolated hypothalamic lesions.

Postirradiation morphea in a breast cancer patient.

We present the case of a 52-year-old woman who underwent lumpectomy and radiation therapy for breast carcinoma and 2 years later presented with changes limited to the breast radiation field including hyperpigmentation, retraction, and skin thickening. These clinical features, along with pathologic findings, were diagnostic of postirradiation morphea. It is important to be aware of this rare complication of radiation therapy because it clinically presents with symptoms mimicking malignancy and may be misinterpreted as recurrent carcinoma or even angiosarcoma.