Significance of H3K27M mutation with specific histomorphological features and associated molecular alterations in pediatric high-grade glial tumors.

PURPOSE: Pediatric high-grade gliomas (pHGGs) constitute almost 15% of all childhood brain tumors. Recurrent mutations such as H3K27M mutation in H3F3A and HIST1H3B genes encoding histone H3 and its variants were identified in approximately 30% of pediatric glioblastomas. This study aimed to ascertain the morphological and molecular characteristics of pHGGs with H3K27M mutation. METHODS: In total, 61 cases of pHGGs (anaplastic astrocytoma, 12; glioblastomas, 49) from four university hospitals were studied. The histomorphological features were examined and immunohistochemistry was performed to evaluate the mutation status of H3K27M, ATRX, IDH1, BRAF V600E, and p53 genes. RESULTS: The study comprised 25 females and 36 males (age range, 1-18 years) with a clinical follow-up of up to 108 months. From the total, 31 patients were positive for H3K27M mutation located in the midline, mostly in the pons and thalamus. H3K27M mutation was commonly associated with ATRX loss (32.3%) and p53 (74.2%) immunoreactivity with a co-expression rate of 25.8%. While IDH1 mutation was not detected in pHGGs with H3K27M mutation, BRAFV600E mutation was rarely observed. Among the various histomorphological features, increased number of mitosis, increased Ki-67 proliferation index, and palisading and geographical necrosis along with small cell patterns were significantly associated with the H3K27M wild-type tumors. Focal infarct-like necrosis and pilomyxoid morphology was significantly associated with these tumors. CONCLUSION: H3K27M mutation occurs exclusively in pHGGs arising from the midline and presents with varied histomorphological features ranging from low-grade pilomyxoid astrocytoma to highly pleomorphic glioblastoma along with ATRX loss and p53 mutations.

New radiological clues in the diagnosis of spindle cell oncocytoma of the adenohypophysis.

AIM: To present three new cases of spindle cell oncocytoma (SCO) from a single centre and to identify new radiological clues in the diagnosis of SCO according to the information obtained from the cases presented. MATERIALS AND METHODS: Three adults with SCO confirmed at histopathology were retrospectively reviewed. The medical records, imaging findings, operative notes, and histopathology findings for each patient were recorded. Magnetic resonance imaging (MRI) findings were evaluated, including tumour localisation, tumour size, signal intensity, imaging features on T1-weighted and T2-weighted images, and contrast enhancement characteristics. The study protocol was approved by the institutional review board. Informed consent was obtained from each patient. RESULTS: T1-weighted imaging (WI) and T2WI demonstrated millimetric hypointense foci and linear signal void areas in all lesions. Consistent with the hypervascular features of the tumour, intense contrast enhancement was observed during the early stages of dynamic contrast enhanced (DCE) MRI. Linear signal void areas showed contrast enhancement, but some of the hypointense millimetric foci remained without contrast enhancement. CONCLUSIONS: Although the radiological findings and preoperative diagnosis of SCO have been reported to be non-specific and impossible, respectively, in the literature, the characteristics of MRI and different patterns of contrast enhancement can help in recognising this rare entity. This article represents a single institution case series of SCOs and also includes the first description of a correlation of the histopathological findings with radiological findings and new clues in the differential diagnosis of SCOs. We described these new radiological clues as "Hasiloglu's Signs".

The importance of hemosiderin deposition in the infant brain: an autopsy study.

BACKGROUND/AIM: Iron is an essential element involved in many metabolic processes. Presence and accumulation of iron in various body systems can result in different outcomes. Its accumulation in the central nervous system (CNS) cannot be detected routinely by application of hematoxylin-eosin staining. Detection of the presence of hemosiderin in the brain and cerebellum by application of Perls' dye is of importance in cases of infant deaths. MATERIAL AND METHODS: In this study, brain and cerebellar specimens obtained from 52 eligible infants  (aged 0-1 years) autopsied in our institute between the years 2010 and 2013, independent of the cause of death, were analyzed in order to detect possible presence of hemosiderin. Perls' dye was used to detect histopathological staining intensity and distribution of hemosiderin in the brain and cerebellum. RESULTS: Cases did not differ significantly as for the patients' age and gender (p =0.473), type of the culprit trauma (p =0.414), death/crime scene (p =0.587), and diagnosis groups (p =0.550). In this autopsy study blue colored hemosiderin granulations, stained with Perls' dye were detected in the brain (n: 39, 75%), and cerebellum (n: 35, 67.3%). A weakly negative, but significant correlation was detected between the postmortem interval and intensity values of cerebellar hemosiderin (Spearman's correlation coefficient: -0.381, p =0.024). A statistically significant difference was found between the distribution scores of cerebral hemosiderin in cases with and without trauma history (p =0.03). Median cerebral hemosiderin distribution scores were 2.5 and 2, respectively. CONCLUSIONS: The detection of a correlation between the presence of cerebral and cerebellar hemosiderin, and postmortem interval in the age group of 0-1 years, should be interpreted as an important finding in the analysis of cerebral iron. The presence of hemosiderin in the CNS may be a significant finding in the elucidation of infant deaths and this procedure should be carried out on a routine basis.Hippokratia 2015; 19 (2):164-171.

Sudden death due to a rare brain tumor: an autopsy case.

UNLABELLED: Sudden death in persons with intracranial neoplasms is a rare mechanism of death detected in the forensic autopsies. 10 years-old girl was brought to a local clinic death shortly after analgesic therapy for headache. Autopsy findings showed a large, solid cerebellar mass. Histological diagnosis was pilomyxoid astrocytoma, low-grade tumor with features alike to pilocytic astrocytomas. In this case report we present and discuss rare autopsy case of pilomyxoid astrocytoma from medicolegal point of view. KEYWORDS: sudden death - brain - pilomyxoid astrocytoma - autopsy.

Age-related histopathological changes in the cardiac conducting system in the Turkish population: an evaluation of 202 autopsy cases.

BACKGROUND: Histopathological features of the cardiac conducting system (CCS) in the Turkish population have not been investigated previously. MATERIAL AND METHODS: We examined CCS of 202 autopsy heart specimens dissected between the years 2004 and 2005 in Bursa Forensic Medicine Institution. Of the 202 cases from all age groups, 154 were males and 48 were females. RESULTS: In our cases, an increase in fibrous and adipose tissue concordant with age, indicating an age-related nature, were detected. Fibrous and fatty tissue infiltration appeared at the age of 35. Fatty infiltration started between the ages 20 and 34 years at the sinoatrial node (SAN). There was no relationship between obesity and fatty tissue infiltration in SAN and atrioventricular node (AVN). In 4 cases calcification and in 19 cases inflammation was observed. Amyloid accumulation was not present. In 7 cases myocardial infarction not involving CCS was seen. In 1 case fibroelastoma was detected. CONCLUSIONS: In the Turkish population age-related fibrosis and fatty infiltration in CCS appeared at the age of 35 years and increased with age. Fatty infiltration in the SAN started at a younger age than that reported in the literature. In cases where the cause of death could not be determined, we could not detect lethal pathological features. However, we think that examination of the CCS will improve the quality of autopsy diagnosis.

Morphometric features of the thyroid gland: a cadaveric study of Turkish people.

BACKGROUND: Although racial and ethnic variations in the morphology of anatomical structures are defined well, the size, shape, and weight of the thyroid gland have not previously been reported in Turkish people. This study provides data about the morphometric features of the thyroid gland, thyroid lobes, and pyramidal lobe, and highlights some anatomical variations in people from the Marmara region in Turkey. MATERIAL AND METHODS: The material for the present study consisted of thyroid glands obtained from 75 male and 15 female adult cadavers aged between 18 and 80 years. A dissection was carried out and the thyroid glands were exposed. The glands were weighed and measured according to the various age groups of the patients. RESULTS: A pyramidal lobe was found to be present in 57.8% of the cadavers (52/90). During midline dissection of the neck 2 males out of 90 cadavers, giving an incidence of 2.22%, did not show an isthmus. The mean thyroid weight was 26.11 ± 8.14 g. In males it was 26.93 ± 7.96 g while in females it was 21.93 ± 7.98 g. CONCLUSIONS: This is the first reported morphometric study on cadaveric thyroid glands from Turkey and it highlights individual and ethnic/racial variations. In order to perform safe and effective surgery and for the accurate diagnosis of thyroid disorders, knowledge of normal anatomy and the variations of the thyroid gland are essential.

The relationship between histomorphological characteristics and Ki-67 proliferation index in meningiomas.

OBJECTIVES: This study had two aims. The first was to use the Ki 67 proliferation index (Ki-67 PI) to study the relationship between the proliferation potential and histopathological features such as mitosis, necrosis, loss of architecture, small cell change, hypercellularity, pleomorphism, brain invasion, dura invasion, bone invasion, and histological grade. The second aim was to compare primary and recurrent meningioma with respect to morphological characteristics and Ki-67 PI values. BACKGROUND: Meningiomas are tumors whose histological features do not predict their biological behavior. Despite their slow growth and even after total resection, recurrence may occur METHODS: A total of 245 meningioma cases in whom Ki-67 PI was studied were included in the study. The cases were assessed with respect to 10 morphological characteristics, and a possible significant relationship between these and Ki 67 PI was statistically tested. RESULTS: We found a statistically significant relationship between Ki-67 PI and mitotic activity, necrosis, loss of architecture, small cell change, brain invasion. In contrast to brain invasion, no significant relationship was present between dura or bone invasion and Ki-67 PI. We identified asignificant increase in the histological grade, mitotic activity and Ki-67 PI value of recurrent tumors, as compared to primary ones CONCLUSION: Ki-67 PI values overlap in different grades. This overlapping might be due to the heterogeneity of biological activity within the tumor tissue (Tab. 2, Fig. 7, Ref. 21).

Ovarian enlargement associated with massive oedema.

Massive ovarian oedema is a rare entity described as accumulation of oedema fluid within the ovarian stroma, separating normal follicular structures. Our case was a 27-year-old woman who presented with a large solid pelvic mass after recurrent episodes of self-limited abdominal pain. On physical examination, she had left abdominal tenderness with minimal rebound and guarding. With a diagnosis of malignant ovarian tumor, an exploratory laparotomy was done and a twisted ovarian mass was found which was excised completely. Histopathological evaluation of the mass revealed massive oedema of the ovary. Massive ovarian oedema should be suspected in women at the fertile age range with solid enlargement of the ovary.

An unusual cause of sudden death: cardiac myxoma.

Primary tumors of the heart are rare; the most common cardiac tumor is atrial myxoma. Sudden death may occur in patients with atrial myxoma, tumor embolization, or obstruction of blood flow at the mitral or tricuspid valve. This report describes an unusual cause of sudden death and the autopsy findings for a 73-year-old man with left atrial myxoma.