Intracanal Optic Nerve Cavernous Hemangioma: A Case Report and Review of the Literature.

BACKGROUND: Cerebral cavernous malformations of the intracanalicular optic nerve are extremely rare lesions. Only a few case reports and 1 case series have been published. We report an additional case with atypical imaging and review the existing literature with attention to time to surgery and imaging characteristics. CASE DESCRIPTION: In a 38-year-old man with progressive visual field deficit, a lesion compressing the left optic nerve in the optic canal was diagnosed. On magnetic resonance imaging, this lesion had a homogeneous signal and was tentatively diagnosed as a meningioma. A left frontolateral craniotomy with extradural skull base approach with neuronavigation was performed for resection and definitive diagnosis of the lesion. Pathologic examination showed a lesion most consistent with a cavernous hemangioma. Follow-up magnetic resonance imaging at 6 months showed no remaining tissue or recurrence. Clinically, there was subjective and objective improvement of sight. CONCLUSIONS: A cerebral cavernous malformation should always be in the differential diagnosis of a lesion causing an optic neuropathy with visual acuity loss and visual field defect. Clinical presentation of an optic neuropathy requires medical imaging; magnetic resonance imaging is the modality of choice in the diagnosis of these lesions. The treatment of cerebral cavernous malformation is gross total resection.

Myopericytoma of the Base of the Finger: Radiological and Pathological Description of a Rare Benign Entity.

A previously healthy 46-year-old woman presented with a mass lesion between the bases of the fourth and fifth fingers of the right hand. The mass had grown progressively over 2 years and started to cause practical difficulties in everyday life. Imaging depicted a hypervascular and well-circumscribed soft tissue tumor with imaging characteristics of a sarcoma. The lesion was treated surgically. The final diagnosis of the specimen upon pathology was a myopericytoma, a benign smooth-muscle cell neoplasm. Myopericytoma is a rare disease entity; however, it is important because it can mimic more ominous conditions.

Accurate detection and quantification of epigenetic and genetic second hits in BRCA1 and BRCA2-associated hereditary breast and ovarian cancer reveals multiple co-acting second hits.

BACKGROUND: This study characterizes the second hit spectrum in BRCA1 and BRCA2-associated breast and ovarian cancers at both gene loci to investigate if second hit mechanisms are mutually exclusive or able to coincide within the same tumor. METHODS: Loss of heterozygosity, somatic point mutations and copy number alterations along with promoter methylation were studied in 56 breast and 15 ovarian cancers from BRCA1 and BRCA2 germline mutation carriers. A mathematical methodology was introduced to quantify the tumor cell population carrying a second hit. RESULTS: Copy neutral LOH was the most prevalent LOH mechanism in this cohort (BC 69%, OC 67%). However, only 36% of BC and 47% of OC showed LOH in all cancerous cells. Somatic intragenic deletions and methylated subclones were also found in combination with (partial) loss of heterozygosity. Unequivocal deleterious somatic point mutations were not identified in this cohort. CONCLUSION: Different mechanisms inactivating the wild type allele are present within the same tumor sample at various extents. Results indicate that BRCA1/2-linked breast and ovarian cancer cells are predominantly characterized by LOH, but harbor a complex combination of second hits at various frequencies.

Melanocytic naevi with perineurial differentiation: a distinctive variant of neurotised naevi and a diagnostic pitfall with desmoplastic melanoma.

AIMS: Spindle cell differentiation is not an uncommon finding in common acquired naevi, and may represent a form of neurotisation with Schwannian differentiation of melanocytes. Perineurial differentiation in this context appears to be very rare, and is only poorly documented in the literature. We therefore aimed to study this rare form of neurotisation in melanocytic naevi more comprehensively. METHODS AND RESULTS: We have identified six melanocytic tumours showing spindle cell morphology and perineurial differentiation from routine and referral material. Clinical data and follow-up were obtained, and the histological and immunohistochemical features were analysed. The tumours affected middle-aged adults (median, 48 years; range, 26-74 years), with a wide anatomical distribution and benign follow-up (median, 13 months; range, 6-48 months). All tumours were nodular and circumscribed but asymmetrical, with extension into the deep dermis and superficial subcutis. A characteristic finding was a biphasic growth pattern with a lentiginous compound naevus in the superficial aspect and abrupt transition to a prominent nodular spindle cell proliferation in the deeper reaches. Spindle cells were bland and uniform, and arranged singly and in short fascicles in a loose fibromyxoid stroma. In areas, a whorled arrangement of slender spindle cells with wavy nuclei was seen. Distinctive intratumoral hypocellular nodules and peripheral lymphoid aggregates were additional features. By immunohistochemistry, the spindle cells were mainly S100-positive melanocytes. In areas, S100-negative/epithelial membrane antigen-positive spindle cells showing coexpression of Glut-1 and claudin-1 were closely admixed. CONCLUSION: This perineurial differentiation probably represents a rare and unusual form of neurotisation. The tumours are benign but may be mistaken for desmoplastic melanoma. Awareness of and careful attention to the clinicopathological and immunohistochemical features allow reliable separation.

Incidental finding of silent appendicitis on (18)F-FDG PET/CT in a patient with small cell lung adenocarcinoma.

We report the incidental diagnosis of acute asymptomatic appendicitis on a fluorine-18-fluorodeoxyglucose positron emission tomography with computed tomography ((18)F-FDG PET/CT) performed for staging of a non small cell lung carcinoma. The patient was asymptomatic and laboratory tests were normal. The case illustrates: a) the possibility to diagnose appendicitis on (18)F-FDG PET/CT and b) the possibility of silent acute appendicitis, although this is a rare occurrence.

Ring chromosome 6 may represent a cytogenetic subgroup in benign thymoma.

Cytogenetic and fluorescence in situ hybridization analysis of a thymoma revealed the presence of an abnormal clone with a karyotype 46,XY,r(6)(p2?q35?).ish r(6)(p2?q35?)(WCP6+,dJ476O18-,dJ62I11-, PAC59C23+,PAC57H24-),der(21)t(6;21)(p25;q22)(dJ62I11+,cosC9a1-). Histologically, the tumor was encapsulated and classified as thymoma type AB (World Health Organization classification) or mixed thymoma (Muller-Hermelink classification), composed of well-formed lobules with sharp demarcation of both the spindly type A and lymphocyte-rich type B components. This finding, together with literature data, strongly suggests that terminal deletion of the short arm of chromosome 6 is a recurrent aberration in thymoma.