Hyaline Globules Research Articles

PAX8 expression in sporadic hemangioblastoma of the kidney supports a primary renal cell lineage: implications for differential diagnosis

Hemangioblastoma is a benign, morphologically distinctive neoplasm of disputed histogenesis that typically occurs in the central nervous system either in the setting of von Hippel-Lindau disease or more often sporadically. Extraneural hemangioblastoma is exceptional and raises a challenging differential diagnosis. Herein, we report a primary renal hemangioblastoma occurring in 51-year-old woman without stigmata of von Hippel-Lindau disease. Histologically, the tumor was composed of sheets of polygonal epithelioid stromal cells with ample pale or eosinophilic, vacuolated cytoplasm in an arborizing capillary network. Tumor cells showed variable nuclear pleomorphism, intranuclear cytoplasmic invaginations, scattered hyaline globules, and psammoma-like calcifications. Some areas showed branching hemangiopericytoma-like vessels with tumor cells radiating from the wall, while other areas were edematous and hyalinized with sparse stromal cells and abundant reticular vessels. Immunohistochemically, the tumor cells reacted strongly and diffusely with antibodies to PAX8, CD10, α-inhibin, S100 protein, neuron-specific enolase, and vimentin, and they showed focal positivity with antibodies to epithelial membrane antigen and AE1/AE3. Tumor cells were negative for CK7, CK8/18, RCC antigen, synaptophysin, chromogranin, c-kit, D2-40, HMB45, melan-A, cathepsin K, SMA, desmin, CD31, CD34, and estrogen and progesterone receptors. Positive immunoreactivity for PAX8 is unexpected and contrasts to central nervous system (CNS) hemangioblastomas, which are essentially always negative for PAX8. This novel finding adds support to the hypothesis that the immunoprofile of extraneural hemangioblastoma varies with site of origin, perhaps as a result of tumor cell lineage and retention of organ-specific markers or acquisition of site-specific antigens due to local factors.

Corpora amylacea in gastrointestinal leiomyomas: a clinical, light microscopic, ultrastructural and immunohistochemical study with comparison to hyaline globules

ContextCorpora amylacea (CA) are inclusions with starch-like composition that occur in various conditions. We have observed CA in gastrointestinal leiomyomas (GILM) and hypothesised that they differ from intracytoplasmic hyaline globules...

Renal Anastomosing Hemangiomas With a Diverse Morphologic Spectrum

Benign vascular lesions have a diverse appearance and can be extremely difficult to classify. We present renal anastomosing hemangiomas from 2 patients that exemplify the potential diverse range of appearances that can occur in this recently described, rare variant of capillary hemangioma. The lesion from one patient was an intravenous hemangioma with closely packed, fenestrated vascular channels that were reminiscent of the splenic red pulp. Also, the endothelial cells contained hyaline globules. On the other hand, the second patient had multifocal tumor. The lesions showed more extensive hyalinization and vascular ectasia reminiscent of cavernous hemangioma. Extramedullary hematopoiesis was a feature in all the tumors, particularly in the second patient where numerous immature blasts were present within vascular spaces.

Disseminated Intravascular Coagulation in a Novel Porcine Model of Severe Staphylococcus aureus Sepsis Fulfills Human Clinical Criteria

Sepsis is a common and often fatal complication in human patients in intensive care units. Relevant and well characterized animal models of sepsis may provide valuable information on pathophysiological mechanisms and be a mean of testing new therapeutic strategies. Large animal models of Staphylococcus aureus sepsis are rare, even though S. aureus increasingly affects human patients. Sepsis changes the haemostatic balance and leads to endothelial cell (EC) activation, coagulopathy and, in severe cases, disseminated intravascular coagulation (DIC). The aim of this study was to characterize the haemostatic and vascular alterations in a novel porcine model of severe S. aureus sepsis, investigating whether the changes fulfill the human clinical criteria for DIC. Five pigs were inoculated intravenously with S. aureus and two control animals were sham-inoculated. Blood samples were collected for thromboelastography (TEG) and assessment of plasma-based haemostatic parameters. Tissue was collected for histopathology and reverse transcriptase quantitative real-time polymerase chain reaction for measurement of mRNA encoding EC markers. All infected animals developed DIC; including procoagulant activation represented by hypercoagulable TEG profiles and prolonged clotting time. Histologically, numerous pulmonary thrombi were present in one pig. Inhibitor consumption was represented by decreasing antithrombin levels in infected pigs. Hyaline globules were found in three infected pigs, confirming fibrinolytic activation. EC activation was identified by expression of von Willebrand factor in small vessels together with elevated mRNA encoding activated EC markers. Severe haemostatic and vascular changes fulfilling the human criteria for DIC were therefore seen in all infected pigs. A tendency towards uncompensated DIC was seen in two animals.

Endodermal Sinus Tumor of Vagina in Infants

Endodermal sinus tumor (or Yolk Sac tumor) of the vagina is a rare malignant germcell tumor which is seen exclusively in children younger than 3 years of age. We report two cases of endodermal sinus tumor of the vagina. In both cases no radiological investigation was done and serum alpha-fetoprotein was elevated. The histopathological examination of both the tumor masses revealed vaginal endodermal sinus tumor. Periodic-acid-Schiff stain with diastase showed diastase resistant hyaline globules. These findings confirmed the diagnosis of endodermal sinus tumor in both cases. Vaginal endodermal sinus tumor is both locally aggressive and capable of metastasis. The serum alpha-fetoprotein level is a useful marker for diagnosis and monitoring the recurrence of vaginal endodermal sinus tumor in infants. Early detection and therapy is important because of its aggressive nature and good response to chemotherapy.

Phylloides Tumor With Numerous Thanatosomes (“Death Bodies”)

Thanatosomes, a form of degenerative intracellular hyaline globules, have been described in various neoplastic and nonneoplastic disease processes in several organs. These structures are indicative of apoptotic cell death. Herein, we report 2 cases of malignant phylloides tumor, both of which showed numerous thanatosomes-to the point of dominating the histological appearance and masking the stromal element. Our subsequently conducted study showed that thanatosomes were present in 14 of 86 (16.3%) high-grade malignant breast tumors. The structures were identified in 5/25 (20%) malignant phylloides tumors, 4/19 (21.1%) metaplastic spindle cell carcinomas, 3/21 (14.3%) invasive carcinomas s/p neoadjuvant chemotherapy, and 2/21 (9.5%) poorly differentiated invasive ductal carcinomas. When present, thanatosomes were typically a rare and focal finding in most types of cases. In malignant phylloides tumors, the structures were relatively more numerous when present. Our study shows that although thanatosomes can be present in several types of malignant breast tumors, they are more common in malignant phylloides tumor. Only rarely, as evident from our 2 index cases, do thanatosomes cause diagnostic difficulty.

Unique histopathologic features of brain metastases from hepatocellular carcinoma.

169 Background: In the era of anti-angiogenic therapy as treatment for advanced hepatocellular carcinoma (HCC), the incidence and importance of brain metastases are increasing. We aimed to study their histopathologic features. Methods: We searched for all patients who were diagnosed to have HCC with brain metastasis from 1999 to 2010 at National Taiwan University Hospital, Taipei, Taiwan. Patients who had HCC with lung metastasis were also included for comparison. Patients with available tissues of both primary and metastatic tumors were enrolled in this study. Tumor slides from paired primary and metastatic HCCs were stained by H and E, and immunohistochemically stained for CK7, p53, Ki67, vimentin, Hes1, and c-Met. The expressions of CK7, p53, and vimentin were graded according to percentages of positive staining, but those of Hes1 and c-Met were recorded as an H score, which was defined as intensity (0, 1, 2, or 3) × percentages of positive staining. Results: A total of 14 patients had available tumor tissues of both primary and metastatic brain tumors. Another 21 patients had tumor tissues of both primary and metastatic lung tumors. The metastatic brain tumors, comparing to the metastatic lung tumors, had significantly more bizarre dilated vessels (86% vs. 14%, p < 0.001), hyaline globules (50% vs. 5%, p = 0.003), higher Hes1 H scores (mean, 245 vs. 131, p = 0.001), and lower c-Met H scores (mean, 15.4 vs. 38.1, p = 0.046). Tumor necrosis also tended to be more common among metastatic brain tumors (93% vs. 62%, p = 0.056). On the contrary, the above differences were not identified between the primary tumors which later developed brain metastasis and those which later developed lung metastasis. When disease progressed from primary liver to brain metastasis, mitosis counts (p = 0.034) and bizarre dilated vessels (p = 0.020) significantly increased, and necrosis (p = 0.059) tended to be more common. Conclusions: Metastatic brain tumors from HCC had unique histopathologic features compared to primary liver tumors or lung metastases. The increased Hes1 expression and decreased c-Met expression in HCC brain metastasis should be further explored. (This study was supported by the grant of NSC101-2314-B-002 -141, 100CAP1020-2 & NTUH.101-N1965.)

Clear cell adenocarcinoma of the renal pelvis: an extremely rare neoplasm of the upper urinary tract

Clear cell adenocarcinoma (CCA) in the urinary tract is a rare neoplasm morphologically identical to the Müllerian counterpart. Clear cell adenocarcinoma is extremely rare in the upper urinary tract. We present a case with CCA of the renal pelvis. Microscopically, the tumor exhibited exophytic growth with predominantly tubulocystic structures, as well as solid and papillary patterns. The neoplastic cells were cuboidal with clear to pale eosinophilic cytoplasm and abundant intracellular and extracellular eosinophilic hyaline globules. By immunohistochemically, the tumor was labeled by cytokeratins and hepatocyte nuclear factor-1β. The patient was still alive without evidence of recurrence in the follow-up period of nineteen months after diagnosis.

“Raspberry bodies,” extracellular hyaline globules and branching hyaline stromal fragments in a fine‐needle aspirate of metastatic clear cell carcinoma of the ovary

Diagnostic CytopathologyVolume 42, Issue 3 p. 230-235 Images in Cytology “Raspberry bodies,” extracellular hyaline globules and branching hyaline stromal fragments in a fine-needle aspirate of metastatic clear cell carcinoma of the ovary Tetyana N. Mettler M.D., Tetyana N. Mettler M.D. Department of Laboratory Medicine and Pathology, University of Minnesota Medical School, Minneapolis, MinnesotaSearch for more papers by this authorJ. Carlos Manivel M.D., J. Carlos Manivel M.D. Department of Laboratory Medicine and Pathology, University of Minnesota Medical School, Minneapolis, MinnesotaSearch for more papers by this authorStefan E. Pambuccian M.D., Corresponding Author Stefan E. Pambuccian M.D. Department of Laboratory Medicine and Pathology, University of Minnesota Medical School, Minneapolis, MinnesotaCorrespondence to: Stefan E. Pambuccian, M.D., Department of Pathology, Loyola University Medical Center, 2160 S. First Avenue, 110-2230, Maywood, IL 60153. E-mail: [email protected]Search for more papers by this author Tetyana N. Mettler M.D., Tetyana N. Mettler M.D. Department of Laboratory Medicine and Pathology, University of Minnesota Medical School, Minneapolis, MinnesotaSearch for more papers by this authorJ. Carlos Manivel M.D., J. Carlos Manivel M.D. Department of Laboratory Medicine and Pathology, University of Minnesota Medical School, Minneapolis, MinnesotaSearch for more papers by this authorStefan E. Pambuccian M.D., Corresponding Author Stefan E. Pambuccian M.D. Department of Laboratory Medicine and Pathology, University of Minnesota Medical School, Minneapolis, MinnesotaCorrespondence to: Stefan E. Pambuccian, M.D., Department of Pathology, Loyola University Medical Center, 2160 S. First Avenue, 110-2230, Maywood, IL 60153. E-mail: [email protected]Search for more papers by this author First published: 16 November 2012 https://doi.org/10.1002/dc.22926Citations: 2Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume42, Issue3March 2014Pages 230-235 RelatedInformation

Solid pseudopapillary tumor of the pancreas: ‘Experiences’ and ‘Lessons’ at a tertiary‐care oncology center

Solid pseudopapillary tumor of the pancreas (SPT) is a rare and fascinating entity of elusive histogenesis and unpredictable biology. It has a peculiar proclivity to afflict young females and involve the pancreatic body-tail region. Cytology diagnosis of these rare neoplasms remains a challenge. We analyzed the cytology features of all SPT cases diagnosed on fine needle aspiration cytology (FNAC) from 2003 to 2009 along with their histopathology slides. Nineteen consecutive cases were diagnosed as SPT on FNAC. Fifteen out of nineteen cases were confirmed as true SPT on histopathology. Amongst the true SPT, all except one occurred in females. Age ranged from 14 to 50 years. Pseudopapillae bearing stout branches terminating in bulbous tips and enclosing transgressing vessels, separated from a collar of tumor cells by a clear zone of myxohyaline coat were pathognomonic of SPT. Singly dispersed monomorphic tumor cells with bland chromatin formed the second diagnostic component of SPT. Nuclear grooves and hyaline globules were in addition helpful in segregating SPT from its close differentials. In four cases diagnosed as SPT on FNAC, histopathology revealed a different final diagnosis (one case each of paraganglioma, extragastrointestinal stromal tumor, metastatic papillary renal cell carcinoma and inflammatory myofibroblastic tumor). Conversely, one case of SPT had been erroneously diagnosed as neuroendocrine tumor on FNAC. Six cases (40%) developed metastasis; commonest site being liver. In conclusion, cytology in conjunction with clinico-radiologic findings plays a key role in making a correct diagnosis. Awareness of unique cytomorphological features is important in distinguishing this tumor from its diverse mimics.

Hyalinized stroma in clear cell carcinoma of the ovary: how is it formed?

Ovarian clear cell carcinoma often shows stromal hyalinization. The main constituents of hyalinization are basement membrane materials, including laminin and type IV collagen. Although it is known that clear cell carcinoma cells produce these materials, it remains unclear whether they can form hyalinized stroma by themselves or if cooperation with stromal cells is required. In the present study, we first reviewed 35 surgical specimens for the pattern of early hyalinization. It occurred either in a globule-like pattern or in a circumferential pattern. In the former, compact hyaline globules abruptly appeared within tumor cell aggregates. In the latter, hyalinized materials appeared around the preceding spherule-like mucoid spaces among tumor cells. In either pattern, hyalinization is most likely to begin in the intercellular spaces among tumor cells, where stromal cells rarely intervene. To verify this, 2 ovarian clear cell carcinoma cell lines (JHOC-5 and HAC-2) were analyzed in vitro. Each cell line was monocultured in suspension: if any deposition occurred in floating multicellular aggregates, it should be in the intercellular spaces. Deposition of type IV collagen occurred in a globule-like pattern (JHOC-5) or a circumferential pattern (HAC-2) within multicellular aggregates, and it developed into a structure comparable with the hyalinized stroma in surgical specimens. Intercellular deposition of type IV collagen was reproduced by culture in 3-dimensional type I collagen gels. All of these findings showed that clear cell carcinoma cells themselves form hyalinized stroma by depositing self-made basement membrane materials in the intercellular spaces.

Solid Pattern Yolk Sac Tumor

Yolk sac tumors may exhibit numerous patterns. One that has received little attention overall, yet is not uncommon, is a solid pattern, which is especially prone to misinterpretation, usually as seminoma, in biopsy specimens from metastatic or mediastinal sites. This distinction is of critical importance as the 2 tumors are treated differently. To determine features useful in the diagnosis of solid yolk sac tumor we reviewed 52 germ cell tumors (28 testicular primaries, 21 metastases from the testis, and 3 mediastinal primaries) that had a yolk sac tumor component with foci of solid growth, defined as a sheet-like arrangement of tumor cells occupying >2 mm and with no or only rare microcysts. Solid yolk sac tumor was almost always associated with other patterns, most commonly microcystic/reticular (75%), glandular (35%), and myxoid (25%). The solid foci consisted of sheets of cells with usually abundant cytoplasm that was mostly (85%) pale to clear and frequently had intercellular basement membrane deposits (75%), rare microcysts (67%), significant nuclear pleomorphism (65%), and hyaline globules (65%). In 2 cases (4%), the cells were small with scant cytoplasm (blastema-like variant). A myxoid background (39%), lymphocytic infiltrate (17%), and an appliqué pattern (8%) were sometimes observed. On immunostaining, AE1/AE3 cytokeratin and glypican 3 provided the most intense and diffuse reactivity for solid yolk sac tumor, whereas α-fetoprotein was negative in 38%. CD117 stained 59%, whereas only rare cells in 1 case (3%) were weakly reactive for podoplanin; OCT3/4 was uniformly negative. We conclude that solid yolk sac tumor can generally be recognized by careful morphologic evaluation, especially its association with other yolk sac tumor patterns, the presence of intercellular band-like deposits of basement membrane, occasional microcysts, nuclear pleomorphism, intracellular hyaline globules, and usual absence of lymphocytes. In difficult cases a concise immunohistochemical panel consisting of AE1/AE3, glypican 3, and OCT3/4 distinguishes solid yolk sac tumor from other neoplasms. α-fetoprotein stains are commonly negative or weak and focal in solid yolk sac tumor and cannot be solely relied on for diagnosis. Common CD117 positivity in solid pattern yolk sac tumors makes it an unreliable discriminator between yolk sac tumor and seminoma.

Ruptured ovarian yolk sac tumor combined with hemoperitoneum in a young girl with abdominal blunt injury

We report our clinical experience concerning the incidental finding of a ruptured ovarian yolk sac tumor combined with hemoperitoneum in a patient with abdominal blunt injury. An girl 8 years of age visited emergency department due to vomiting and persistent abdominal pain after abdominal blunt injury. Physical examination revealed pale conjunctiva, abdominal distension, and tenderness over bilateral lower abdomen without any obvious peritoneal sign. After stabilization of her condition, one huge pelvic tumor with ascites was identified by abdominal sonography and computed tomography scan. Subsequently, hemoperitoneum was confirmed by paracentesis procedure. During exploratory laparotomy, one ruptured left ovarian tumor with bleeding was identified. Therefore, she underwent left oophorectomy and left salpingectomy. Typical structures of Schiller-Duval bodies and hyaline globules in the tumor cells were identified. Biopsy of the omental tissues also confirmed metastatic lesions of the tumor. Ovarian yolk sac tumor (FIGO Stage 3) was confirmed. She received four courses of chemotherapy after the operation and received subsequent regular follow-up at the hospital with an uneventful recovery. This case highlights the possibility of ruptured ovarian yolk sac tumor after abdominal blunt injury as the cause of internal bleeding, and it should be taken into consideration as one possible etiology of hemoperitoneum in a young girl.

Intracellular and extracellular hyaline globules in endobronchial ultrasound‐guided transbronchial needle aspiration of mediastinal lymph node: A clue for the diagnosis of metastatic hepatocellular carcinoma

Intracellular and extracellular hyaline globules in endobronchial ultrasound‐guided transbronchial needle aspiration of mediastinal lymph node: A clue for the diagnosis of metastatic hepatocellular carcinoma

Cytologic Findings of Clear Cell Adenocarcinoma of the Urethra: A Case Report

Clear cell adenocarcinoma of the urethra is a rare disease entity with an uncertain histogenesis. Here, we present a case of primary clear cell adenocarcinoma of the female urethra with its cytological findings. A 54-year-old woman presented with a painless gross hematuria lasting 3 months. On vaginal sonography, there was a sausage-like, elongated mass in the urethra, measuring 3.8×4.3 cm. The voided urine cytology revealed small clusters of rounded or papillary cells. The necrotic debris and inflammatory cells were present within some clusters of tumor cells. These tumor cells were enlarged and had abundant clear or granular cytoplasm with cytoplasmic vacuoles. The nucleus was granular and contained vesicular chromatin with prominent nucleoli. The hobnail cells and hyaline globules were also present as in a histologic section. The histologic findings were compatible with clear cell adenocarcinoma. The tumor showed distinctive cytological features. Cytologically, however, it is necessary to make a differential diagnosis from other adenocarcinoma or high-grade urothelial carcinoma.

Unusual thyroid carcinoma with excessive extracellular hyaline globules: a case of “hyalinizing papillary carcinoma”

We present an unusual case of papillary thyroid carcinoma in a 47-year-old Japanese woman. The tumor, 0.8 cm in diameter, was located in the upper left lobe of the thyroid. Histologically, we observed a microfollicular-like and trabecular arrangement of the tumor cells with marked hyalinized stroma and hyaline globules. Immunohistochemically, tumor cells were positive for thyroglobulin and thyroid transcription factor 1. Hyaline stroma and globular bodies were immunopositive for laminin and type IV collagen. MIB-1 index was approximately 1% without membranous immunoreactivity. Under the electron microscope, hyaline stroma and globules showed electron-dense, complex meshwork structures composed of granular and fibrous elements similar to the structure of the lamina densa. Genetic analysis demonstrated a BRAF(V600E) mutation. Based on these findings, we diagnosed the present tumor as a rare morphological variation of papillary thyroid carcinoma with excessive hyaline globules consisting of basal membrane materials.

Embryonal (Undifferentiated) Sarcoma of the Liver With Peripheral Angiosarcoma Differentiation Arising in a Mesenchymal Hamartoma in an Adult Patient

Embryonal (undifferentiated) sarcoma of the liver (ESL) is a rare malignant neoplasm composed of undifferentiated sarcomatous tissue. We are presenting a case of a 74-year-old woman diagnosed with an ESL arising from a mesenchymal hamartoma of the liver (MHL). Both lesions occur typically in childhood, with only rare reported cases in adults. Histologically, the mass consisted primarily of loose myxoid stroma admixed with bland spindle cells and extensive, cystic (lymphangioma-like) degeneration. However, also present peripherally were markedly atypical cells (including multi-nucleated forms) and hyaline globules. Additionally, atypical cells with a sinusoid tectorial growth pattern were identified, which were positive for CD31, CD34 and Factor VIII. The tumor cells of ESL are classically described as being negative for tissue-specific immunohistochemical markers. However our case demonstrated focal positivity for vascular markers CD31, CD34 and Factor VIII and this along with the sinusoidal tectorial growth pattern, mimicked an angiosarcoma.

Uterine Glomeruloid Hemangioma in a Patient Without POEMS Syndrome

Cutaneous glomeruloid hemangioma is a hallmark of POEMS syndrome. These patients have elevated serum levels of vascular endothelial growth factor. The authors report an extracutaneous uterine glomeruloid hemangioma in an 82-year-old woman with a history of breast and endometrial carcinomas. Within the lumen of myometrial vessels, a lobular, glomeruloid proliferation of capillary-like CD31 and vascular endothelial growth factor receptor-1-positive endothelial cells was found. The capillary loops were lined by endothelial cells, most of them containing PAS-positive and immunoglobulin-positive eosinophilic hyaline globules (thanatosomes). This vascular proliferation was consistent with a glomeruloid hemangioma. Although an extracutaneous glomeruloid vascular proliferation has been found in the retroperitoneal adipose tissue in a patient with POEMS syndrome, this study reports what seems to be the first case of visceral glomeruloid hemangioma in a patient without POEMS syndrome. The authors hypothesize that the glomeruloid endothelial cell proliferation with vascular endothelial growth factor receptor-1 expression may be a paraneoplastic phenomenon.

Case report of death from falling: Did heart tumor cause syncope?

A healthy man in his 30s was working on the balustrade of stairs on the second floor. He suddenly fell downstairs without saying anything. On emergency hospitalization, chest echogram showed left hemothorax. Cardiac echogram showed a floating mass from the mitral valve in the left ventricle and severe mitral regurgitation. Surgery for hemothorax and pulmonary contusion was immediately undertaken. However, bleeding from pulmonary contusion could not be controlled and he underwent cardiopulmonary arrest. Autopsy showed a white, elastic, pendulous mass in the left atrium and a white mass in the lower lobe of the left lung. Tumor histology showed a reticular pattern, Schiller-Duval bodies, eosinophilic hyaline globules, and positive staining for α-fetoprotein. We diagnosed primary lung yolk sac tumor with metastatic intracardiac yolk sac tumor, a rare and highly malignant germ cell tumor. It usually arises in the ovaries and testes, and intracardiac yolk sac tumor is rare. Intracavitary tumors induce obstruction of inflow into and outflow from the ventricular cavity. The most common clinical presentation is dyspnea and syncope. In the present case, metastatic cardiac yolk sac tumor might have disturbed cardiac outflow and affected hemodynamics, probably causing syncope. Unfortunately, he was in a high place at that time and fell to receive pulmonary contusion that led to death. Autopsy may sometimes reveal latent diseases which might be related to the cause of death. We should perform autopsy thoroughly to diagnose not only the cause of death but also the factors leading to death.

Yolk-Sac Tumor of the Postauricular Region: Case Report and Review of the Literature

draining. The patient had intermittent bleeding from the mass and the laboratory examination showed severe anemia, for which she receive d2Uo fblood. There was a red hemorrhagic vegetative mass in the left external auditory canal. The facial nerve and other lower cranial nerves were normal. A computed tomographic scan of the temporal bone showed a large solid mass in the postauricular soft tissue with extension to the mastoid and middle ear and erosion of the bony septets (Fig 2). The mass had also extended into the infratemporal space and occupied most of this space. There were several enlarged lymph nodes in the II, III, and V levels of the right side of the neck. Magnetic resonance imaging examination showed a mass with extension to the mastoid and middle ear (Fig 3). An incisional biopsy of the mass disclosed a malignant germ cell tumor. The serum -fetoprotein (AFP) level was elevated. Surgical resection of the tumor was performed to remove the necrotic tissue. Lateral temporal bone resection, total parotidectomy with dissection of facial nerve, comprehensive resection of the soft tissue of the postauricular and infratemporal regions, and posterolateral neck dissection were performed. After complete gross ablation of the tumor, a plastic surgeon (M.H.) used a temporalis muscle flap, which was rotated over its pedicle, to cover the exposed bone, elements, and vessels. The result of the pathologic evaluation using immunohistochemical studies indicated a YST. The pathologic examination of the mass showed reticular and microscopic areas formed by a loose meshwork lined by flat and cuboidal cells with pleomorphic nuclei, prominent nucleoli, frequent mitotic figures and vacuolated cytoplasm, and a perivascular organoid arrangement of tumoral cells (Schiller-Duval bodies) and solid undifferentiated areas. Intracytoplasmic and extracellular hyaline globules that stained positively with periodic acid-Schiff and multiple hemorrhagic areas were also seen. Immunohistochemistry was strongly positive for AFP and periodic acid-Schiff, focally positive for chromogranin, and positive for keratin (Fig 4). The surgical margin was free of tumor and 0 of 17 lymph nodes was involved. The patient was advised to undergo chemotherapy, but the parents refused. After 9 months of follow-up, there has been no sign of recurrence, the patient is asymptomatic, and the serum AFP level is within the normal range.