BACKGROUND: Superficial siderosis (SS) of the central nervous system is a rare disease characterized by deposition of hemosiderin along the leptomeninges due to chronic or recurrent bleeding into the subarachnoid space. The association of unruptured intracranial aneurysm (IA) and cortical SS is quite rare.
METHODS: A systematic literature review to assess possible commonalities and/or differences of previous reported cases was undertaken. We report an additional case from our institution.
RESULTS: A 40-year-old woman presented with a history of generalized seizures over the past year. There was no clinical history suggestive of aneurysm rupture. Magnetic resonance imaging revealed 2 aneurysms of the right middle cerebral artery (MCA) bifurcation associated with hemosiderin deposition along the right sylvian fissure and a third aneurysm of the left MCA bifurcation. Magnetic resonance imaging showed wall enhancing thickening of the larger right MCA aneurysm. The patient underwent surgical clipping of all 3 MCA aneurysms in a staged procedure. Histological examination revealed hemosiderin deposits within the aneurysm wall and surrounding gliosis.
CONCLUSIONS: Our literature review found 24 reported cases of unruptured IA associated with cortical SS. The possible source for leakages could be neovessels visible in IA walls. The case reported illustrates an uncommon presentation of recurrent bleeding from an IA as a source of SS. The presence of an apparently unruptured IA surrounded by cortical SS on imaging studies is of high relevance as this should be considered a sign of aneurysm wall instability and should indicate prompt treatment.

BACKGROUND: Intranodal palisaded myofibroblastoma (IPM) is an exceedingly rare benign mesenchymal tumor of the lymph nodes. Magnetic resonance imaging (MRI) findings are unspecific, which may present diagnostic challenges to fine-needle aspiration cytology (FNAC). The histological and immunohistochemical features of IPM are unique.
METHODS: A previously healthy 40-year-old male patient presented a slow-growing solitary left inguinal mass. FNAC revealed clustered cells within a metachromatic stroma, single spindle cells without atypia, hemosiderin pigment, and siderophages. An MRI showed a central hyperintense septum in fat-suppressed, T2-weighted sequences. The excised lymph node contained central haphazard fascicles of spindle cells with focal nuclear palisading, hemosiderin pigment, extravasated erythrocytes, and hemorrhagic areas. Vimentin and smooth muscle actin were diffusely positive. Amianthoid collagen fibers were not clearly observed.
CONCLUSIONS: IPM is an extremely rare mesenchymal benign intranodal tumor that should be included in the differential diagnosis of spindle cell lesions in the inguinal region.

Superficial siderosis of the central nervous system results from subpial hemosiderin deposition due to chronic low-grade bleeding into the subarachnoid space. The confluent and marginal subpial hemosiderin is best appreciated on iron-sensitive magnetic resonance imaging sequences. With widespread use of magnetic resonance imaging, the disorder is increasingly being recognized, including in asymptomatic individuals. Gait ataxia, often with hearing impairment is a common clinical presentation. A clinical history of subarachnoid hemorrhage is generally not present. A macrovascular pathology is generally not causative. The most common etiology is dural disease, often dural tears. Prior or less commonly ongoing symptoms of craniospinal hypovolemia may be present. Common etiologies for dural tears include disc disease and trauma, including surgical trauma. Patients with dural tears due to herniated and calcified discs often have a ventral intraspinal fluid collection due to cerebrospinal fluid leak. A precise identification of the dural tear relies on multimodality imaging. It has been speculated that chronic bleeding from fragile blood vessels around the dural tear may be the likely underlying mechanism. Surgical correction of the bleeding source is a logical therapeutic strategy. Clinical outcomes are variable, although neuroimaging evidence of successful dural tear repair is noted. The currently available data regarding use of deferiprone in patients with superficial siderosis is insufficient to recommend its routine use in patients. ANN NEUROL 2021;89:1068-1079.

Superficial siderosis is a rare disease resulting from the deposited hemosiderin owing to repeated subarachnoid hemorrhage. It has been reported that hemosiderin deposits on the brain surface and brain parenchyma causes nerve disorder, resulting in progressive and irreversible hearing loss, cerebellar ataxia and pyramidal disorder. The brain tumor is one of the cause of superficial siderosis. A 16-year-old female present a nearby hospital with complaints of absence seizure. A magnetic resonance imaging (MRI) revealed a heterogeneously enhanced mass at the right temporal lobe. Susceptibility-weighted imaging revealed diffuse and extensive superficial siderosis on the brain surface. The tumor was gross totally removed and diagnosed as glioneuronal tumor. The patient had been well, although susceptibility-weighted imaging performed one year after the surgery showed superficial siderosis remained. Early diagnosis and prevention of bleeding sources are recommended to prevent symptom progression associated with superficial siderosis. Susceptibility-weighted imaging is considered useful for early detection of superficial siderosis.

Background and aim: Hemosiderotic fibrolipomatous tumor (HFLT) is a locally invasive tumor composed of mature adipocytes accompanied by spindle cells containing hemosiderin deposition. In 2013, it was categorized by WHO as a soft tissue tumor with uncertain differentiation. So far, the literature has reported 60 cases but primary HFLT in bone has never before been reported. We set out to investigate the clinicopathological features of primary HFLT in bone. Methods: We retrospectively reviewed the clinical, imaging, histological, and immunophenotypic features and treatment of 1 case of primary HFLT in bone, and combined this with literature discussion. Results: HFLT occurred in the lateral femoral condyle of a 50-year-old male patient, which might have been overlooked were it not for the knee-joint pain and dysfunction. CT and MRI showed osteolytic bone destruction with a clear 4.0-cm diameter boundary, diagnosed as cystic damage of the lateral condyle of the left femur. SPECT metabolism was not active. Histologically, the lesion was composed of different proportions of mature fat cells, spindle cells, and hemosiderin. Immunohistochemistry revealed spindle cells expressing vimentin, p63, but not CD34, calponin, and others. The tumor tissue was thoroughly removed by curetting, and a bone graft was carried out after immersion in anhydrous ethanol. At the 11-month postoperative follow-up, the patient was recovering well. Conclusions: Primary HFLT in bone is extremely rare. In imaging, it can easily be misdiagnosed as a bone cyst. Histological morphology of the current case is similar to that of soft tissue HFLT.

The color of urine, once considered by uroscopists to give the most important clues to the diagnosis, still can provide some diagnostic clues in modern medicine. Pigmented cells are an uncommon and surprising find in urine cytology and can at the same time provide important diagnostic clues or represent a dangerous pitfall. We present a review of the significance of pigmented cells in urine cytology. The presence of intracellular pigment granules; their color, size, shape, and variation in size and shape; as well as their staining reactions with special stains can provide useful diagnostic insight, especially when interpreted in the cytologic context (type of pigmented cell and its degree of atypicality) and patient\'s clinical context. The main differential diagnosis of cytoplasmic pigmented granules includes hemosiderin, lipofuscin, and melanin, each having a different pathogenesis and significance. The goal of this paper is to describe the morphological, histochemical, and ultrastructural characteristics of the pigments seen in urinary cytology, and to review the benign and malignant conditions associated with them.

Superficial siderosis (SS) of the central nervous system is a disease characterized by deposition of hemosiderin in the leptomeninges (arachnoid and pia mater) due to chronic intradural bleeding. One of the etiologic mechanisms proposed is a dural breach secondary to trauma with a consequent arachnoidocele in contact with an exuberant venous plexus. We describe a unique case of clival arachnoidocele treated by an endoscopic endonasal approach and closure of the defect with fat and nasoseptal flap.
A 35-year-old man with a history of severe head trauma 20 years ago presented with hearing deficit and a mild motor ataxia impairing gait. Magnetic resonance imaging disclosed hemosiderin deposition throughout the brain cortical layer and in the cerebellum, affecting the dentate nucleus as well. A computed tomography revealed an osteolytic formation in the clivus, involving the inner bone table and bone marrow. The patient was then submitted to an endoscopic endonasal transclival approach to close the defect.
SS may be a result of several etiologies generating repetitive meningeal bleeding. Our patient had the diagnosis of posttraumatic clival arachnoidocele and SS probably related to trauma with some dural injury. An endoscopic endonasal approach with tear reconstruction is feasible and successful to address clival arachnoidoceles and, in this case, to avoid progression of the SS.

BACKGROUND: Colorectal perineuriomas are uncommon benign mucosal-based proliferations of mesenchymal cells that express perineurial markers, often associated with colonic crypts displaying a serrated/hyperplastic architecture. The vast majority of cases arise distal to the splenic flexure and have been described as sessile polyps. Using molecular analysis, BRAF mutations have been demonstrated in the serrated crypt epithelium. We report a new case of perineurioma presenting as a pedunculated polyp in the transverse colon, with prominent hemosiderin deposits in the uninvolved lamina propria that separated the perineurial proliferation from the surface epithelium, a previously unreported histological finding. By using immunohistochemistry, we demonstrated the presence of BRAF V600E mutated protein in the serrated crypt epithelium. In addition, a review of the literature on colorectal perineurioma is provided.
METHODS: A 5 mm pedunculated polyp was removed from the transverse colon of a 42 year old man who presented with epigastric pain, weight loss and rectal bleeding. A proliferation of uniform plump spindled cells expanded the lamina propria and separated serrated colonic crypts. The epithelial component closely resembled microvesicular hyperplastic polyp. Immunohistochemical stains for epithelial membrane antigen (EMA), glucose transporter 1 (GLUT1) and collagen IV were positive in the stromal proliferation. A mutation-specific monoclonal antibody directed against BRAF V600E showed positive cytoplasmic staining in the serrated crypt epithelium but not in the perineurial proliferation. Conspicuous hemosiderin deposition was seen in the inflamed lamina propria between the perineurial proliferation and the surface epithelium.
CONCLUSIONS: Although the majority of colorectal perineuriomas occur in the sigmoid colon and rectum and are described as sessile polyps, colorectal perineurioma can present as a pedunculated polyp proximal to the splenic flexure as described in this case. Conspicuous hemosiderin deposition can be seen in the superficial lamina propria. BRAF mutations are limited to the serrated crypt epithelium.

The superficial siderosis (SS) of the central nervous system (CNS) is a rare condition characterized by a wide range of neurological manifestations directly linked to an acquired iron-mediated neurodegeneration. First described more than 100 years ago, only recently SS has been divided into two distinct entities, according to the distribution of iron deposition in the CNS: cortical superficial siderosis (cSS) and infratentorial superficial siderosis (iSS). Here we describe an adult case of iSS, with detailed clinical and radiological features. Moreover, we extensively review the literature of SS, particularly focusing on the pathogenesis, clinical-radiological classification, diagnostic algorithm and treatment options of this rare condition.

BACKGROUND: Klippel-Trenaunay-Weber syndrome (KTWS) is a rare congenital vascular disorder characterized by the classic triad of cutaneous nevi, venous varicosities, and osseous and soft tissue hypertrophy of the affected limb. Various vascular anomalies of the central nervous system have also been described in patients with KTWS. The English language literature to date contains 6 reports of associations between KTWS and spinal cord cavernous angioma (CA), but management of these patients has not been well described.
METHODS: A 23-year-old woman was admitted to our institution with acute onset of leg weakness accompanied by upper back pain. Thoracic magnetic resonance imaging of the spinal cord showed a heterogeneous mass with a slit component at the T1-2 level. The patient underwent left hemilaminectomy followed by removal of the tumor, and her neurologic symptoms improved postoperatively. Pathologic examination showed the spinal lesion was characterized by hemosiderin deposition and thin-walled vascular channels surrounded by fibrous tissue.
CONCLUSIONS: This is the first report to provide a detailed pathologic description of the features of spinal CA in a patient with KTWS. Assessment of the clinical features and management of CA associated with KTWS are discussed. This syndrome is rare, and further experience in the treatment of these patients is needed. However, considering that the pathologic findings of spinal CA in patients with KTWS include the typical features of CA, the management of CA in patients with KTWS may be identical to management of isolated CA.