Mucopolysaccharidosis (MPS) is an inherited metabolic disease and a member of the group of lysosomal storage disorders. Its hallmark is a deficiency of lysosomal enzymes involved in the degradation of mucopolysaccharides, also known as glycosaminoglycans (GAGs). The products of GAG degradation accumulate within lysosomes and in the extracellular space, thereby interfering with the degradation of other macromolecules. This process leads to chronic degeneration of cells, which in turn affects multiple organs and systems. There are seven distinct types of MPS (I, II, III, IV, VI, VII, and IX), which are divided into subtypes according to the deficient enzyme and the severity of the clinical picture. Although clinical manifestations vary considerably among the different types of MPS, the central nervous system (CNS) is characteristically affected, and magnetic resonance (MR) imaging is the method of choice to evaluate brain and spinal cord abnormalities. Enlarged perivascular spaces, white matter lesions, hydrocephalus, brain atrophy, cervical spinal canal stenosis with or without spinal cord compression and myelopathy, and bone abnormalities in the skull and spine (dysostosis multiplex) are typical imaging findings described in the literature and reviewed in this article. The differential diagnosis of MPS is limited because the constellation of imaging findings is highly suggestive. Thus, radiologists should be aware of its typical neuroimaging findings so they can recognize cases not yet diagnosed, exclude other metabolic diseases, monitor CNS findings over time, and assess treatment response. (©)RSNA, 2016.

Although abdominal cryptococcomas and visceral cryptococcal lymphadenitis as part of disseminated fungal infection have been reported mostly in HIV-infected patients, localized intra-abdominal involvement due to Cryptococcus gattii has not been previously described in non-HIV-infected patients. In general, a smaller proportion of cryptococcosis is caused by C. gattii. We report here on a type II diabetic HIV-negative patient who presented with a localized intra-abdominal cryptococcal mass due to C. gattii. In addition, we review the general aspects of intra-abdominal and gastrointestinal involvement by Cryptococcus neoformans in the literature and discuss the importance of identifying the C. neoformans varieties and C. gattii in routine laboratories.

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Background Mucopolysaccharidoses (MPS) is a group of hereditary multisystemic lysosomal disorders. Most neuroimaging studies in MPS have focused on the supratentorial compartment and craniocervical junction abnormalities, and data regarding posterior fossa findings are scarce in the literature. Thus, our purpose is to describe posterior fossa findings on magnetic resonance imaging (MRI) of MPS patients. Methods We reviewed routine MRI scans of MPS patients being followed up at our institution (types I, II, III, IV, and VI), focusing on posterior fossa structures. Results Forty‐seven MPS patients were included. MRI‐visible perivascular spaces were commonly found in the midbrain and adjacent to the dentate nuclei (85% and 55% of patients, respectively). White‐matter lesion was not identified in most cases. Its most frequent localizations were in the pons and cerebellum (34% and 30% of patients, respectively). Enlargement of cerebrospinal fluid (CSF) spaces in the posterior fossa was present in 55% of individuals and was more frequent in neuronopathic patients (73% vs 40%; P = .02). Cerebellar volume was classified as normal, apparent macrocerebellum, atrophic, and hypoplastic in 38%, 38%, 21%, and 3% of patients, respectively. A depression of the posterior fossa floor in the midline sagittal plane was found in 22 patients (47%), which was statistical significantly associated with enlargement of CSF spaces (P = .02) and with apparent macrocerebellum (P = .03). Conclusion The present study compiled the main posterior fossa findings in MPS patients. Classically described in the supratentorial compartment, MRI‐visible perivascular spaces, white matter lesions, and enlarged perivascular spaces were also found in the posterior fossa. However, atrophy, which commonly affects cerebral hemispheres, was not the most frequent cerebellar morphology found in our study. Moreover, potential findings for future research were described.

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Collision tumors are defined as the presence of two contiguous histologically different lesions composed of benign and/or malignant components. They are infrequent entities and have been reported in various organs and systems. The most common type of collision tumor in the adrenal gland is the association of two benign lesions, adenoma and myelolipoma. Modification in image characteristics or unexpected growth of an adrenal tumor previously characterized as a benign lesion should be suspicious for collision tumor with a new aggressive component. In this article, we present a case of renal carcinoma metastasis within a previously known adrenal adenoma.

Mucopolysaccharidosis (MPS) is an inherited metabolic disease and a member of the group of lysosomal storage disorders. Its hallmark is a deficiency of lysosomal enzymes involved in the degradation of mucopolysaccharides, also known as glycosaminoglycans (GAGs). The products of GAG degradation accumulate within lysosomes and in the extracellular space, thereby interfering with the degradation of other macromolecules. This process leads to chronic degeneration of cells, which in turn affects multiple organs and systems. There are seven distinct types of MPS (I, II, III, IV, VI, VII, and IX), which are divided into subtypes according to the deficient enzyme and the severity of the clinical picture. Although clinical manifestations vary considerably among the different types of MPS, the central nervous system (CNS) is characteristically affected, and magnetic resonance (MR) imaging is the method of choice to evaluate brain and spinal cord abnormalities. Enlarged perivascular spaces, white matter lesions, hydrocephalus, brain atrophy, cervical spinal canal stenosis with or without spinal cord compression and myelopathy, and bone abnormalities in the skull and spine (dysostosis multiplex) are typical imaging findings described in the literature and reviewed in this article. The differential diagnosis of MPS is limited because the constellation of imaging findings is highly suggestive. Thus, radiologists should be aware of its typical neuroimaging findings so they can recognize cases not yet diagnosed, exclude other metabolic diseases, monitor CNS findings over time, and assess treatment response.

No abstract