Major depression in Parkinson's disease and the mood response to intravenous methylphenidate: possible role of the "hedonic" dopamine synapse.

The euphoric response to equivalent doses of intravenous methylphenidate (MTP) was assessed in a group of 13 Parkinsonian patients affected by major depression, in a group of 11 nondepressed Parkinsonians, in a group of 14 nonparkinsonian subjects suffering from major depression, and finally in a group of 12 controls with no CNS or psychiatric disease. Subjects of all four groups were matched for age, sex and other main characteristics. Depressed and nondepressed Parkinsonians were also matched for duration and severity of illness, and for the type of antiparkinsonian treatment. The response to MTP was evaluated in the context of a double-blind, placebo-controlled study. Parkinsonian patients with major depression exhibited a significant lack of sensitivity to the euphoriant effects of MTP, in comparison with the other three groups. Euphoria produced by central stimulants has been shown to depend on the activity of a dopamine synapse in humans, which is thought to be situated at the limbic terminals of dopamine neurons located in the ventral tegmental area. Degeneration of this system may have predisposed our Parkinsonian patients to major depression

Adrenocortical tumors with myxoid features: a distinct morphologic and phenotypical variant exhibiting malignant behavior.

Myxoid changes have been rarely reported both in adrenocortical adenomas and carcinomas. The recent observation by our group of an adrenal myxoid tumor with morphologically borderline features, but aggressive clinical behavior prompted us to review a series of 196 adrenocortical lesions, comprising 122 carcinomas and 74 adenomas, to define the morphologic, phenotypical and clinical characteristics of adrenocortical tumors with myxoid features. Fourteen cases, including 12 carcinomas and 2 borderline tumors, formed the basis of this report, and were characterized by a variably abundant myxoid component (from 5% to 90% of tumor) and 2 distinct cellular growth patterns: the first (10 cases), mostly associated with a predominant myxoid stromal component, was made of small cells with mild atypia arranged in cords and microcysts; the second (4 cases) was characterized by focal myxoid changes in tumors otherwise similar to conventional adrenocortical carcinoma, with large atypical cells having an eosinophilic cytoplasm and a diffuse or nodular architecture. The above mentioned patterns were absent in all adenomas reviewed. A peculiar reactivity to neurofilaments was seen, mostly associated to the presence of predominant rather that focal myxoid stromal changes, and in 40% of conventional adrenocortical carcinomas, thus representing an undescribed potential pitfall in the differential diagnosis of adrenal lesions. Myxoid adrenocortical tumors probably represent a rare but histologically and phenotipically distinct entity and, although rare cases of benign lesions are on record, they seem to be generally associated to morphologic and clinical features of malignancy