Granular Eosinophilic Cytoplasm Research Articles

Oncocytic intraductal papillary mucinous neoplasm with carcinomatous degeneration

A 68-year-old man presented with painless jaundice without weight loss. Laboratory results revealed a total bilirubin of 9.1 mg/dL (0.4–1.4 mg/dL), lipase of 672 U/L (0–61 U/L), and CA 19-9 of 2 U/mL (≤36]. The aspartate aminotransferase and alanine aminotransferase levels were 142 U/L (15–40 U/L) and 320 U/L (5–58 U/L), respectively, and the alkaline phosphatase was 324 U/L (39–70 U/L). A CT scan demonstrated biliary dilation and a multicystic lesion in the pancreatic head. ERCP revealed a distal biliary stricture across which a stent was placed. Cytologic brushings demonstrated dysplastic features. EUS revealed that the pancreatic duct was dilated to 1 cm in the neck of the pancreas. In the head, there was a large 5-cm cystic lesion that contained a 2-cm hyperechoic mural nodule and a solid 2-cm hypoechoic component, which the biliary stent traversed (A). Smaller nodules emanated from the wall of the cyst in a popcorn-like fashion. Transduodenal FNA of the solid component was performed, and cytology revealed adenocarcinoma (B). The patient subsequently underwent pancreaticoduodenectomy. The surgical specimen revealed solid components and multiple cysts containing tan papillary material (C). Histology revealed exuberant intraductal papillae consistent with intraductal papillary mucinous neoplasm (IPMN) (D) and regions of high cellularity consistent with adenocarcinoma (E). Cells contained extensive granular eosinophilic cytoplasm (B, F), consistent with the unusual oncocytic type IPMN.

Myometrial Xanthomatosis

We report 3 unique cases of extensive myometrial infiltration by foamy histiocytes in uteri removed for benign conditions. The histologic findings were similar and consisted of diffuse infiltration of myometrium by clusters, cords, and sheets of CD163-positive histiocytes with no other significant inflammatory cell component. Most of the histiocytes had pale, vacuolated, or foamy cytoplasm, but in 1 case eosinophilic granular cytoplasm was also present. In all cases, the nuclei were small and eccentric. No mitotic figures were identified. All cases involved young, parous women who had remote prior surgical interventions involving the uterus; 2 patients had a prior cesarean section and 1 had a prior therapeutic abortion. There was no associated neoplastic or infectious condition in any of the cases, and no patient had a prior history of pelvic inflammatory disease. Although we were unable to obtain more detailed obstetric history, an exuberant and persistent reaction to the surgical procedure and/or to a carrier substance for uterotonic intramyometrial injection may be the basis for this unusual reaction, which we designate as myometrial xanthomatosis.

Fibrolamellar hepatocellular carcinoma presenting with budd-chiari syndrome, right atrial thrombus, and pulmonary emboli

CT, computed tomography; FLHCC, fibrolamellar hepatocellular carcinoma; HCC, hepatocellular carcinoma; IVC, inferior vena cava. A 24-year-old man was evaluated for 3 months of abdominal pain and new onset of shortness of breath, increased abdominal girth, and leg swelling. On physical examination, he was tachypneic, had dullness in flanks, and bilateral lower extremity edema. Liver biochemical tests were notable for marginal derangement and a normal alpha-fetoprotein. An abdominal computed tomography (CT) scan showed an 11.5-cm hepatic mass with satellite lesions, ascites, tumor extension into the inferior vena cava (IVC) causing obstruction, and bland thrombus extending from the lower IVC to the femoral veins bilaterally (Fig. 1A). A chest CT showed bilateral pulmonary emboli and bilateral pleural effusions. A 2D echocardiogram showed a presumed right atrial tumor thrombus (Fig. 1B). A liver biopsy showed large polygonal tumor cells with eosinophilic granular cytoplasm (positive stain for Heppar-1) surrounded by abundant fibrous stroma in parallel lamellae, consistent with a well-differentiated fibrolamellar variant of hepatocellular carcinoma (Fig. 1C,D). Given his advanced disease, he was not a candidate for hepatectomy, systemic chemotherapy, vascular intervention, or liver transplantation and was discharged to hospice care with symptomatic palliation. (A) Abdominal CT shows the presence of a large hepatic mass invading the inferior vena cava with ascites and bland thrombus in the lower inferior vena cava extending to the iliac veins. (B) 2D echocardiogram showing the presence of a right atrial thrombus. (C) Liver biopsy showing large polygonal tumor cells with eosinophilic granular cytoplasm surrounded by abundant fibrous stroma in parallel lamellae. (D) Liver biopsy showing cytologic features that include large nuclei with a single prominent nucleolus and pale pink globules in the cytoplasm. Fibrolamellar hepatocellular carcinoma (FLHCC) differs from traditional hepatocellular carcinoma (HCC) in patient demographics (mean age 25 years, equal sex distribution), and absence of underlying cirrhosis or usual risk factors. 1 Our patient presented with rare manifestations that included secondary Budd-Chiari syndrome and significant clot burden causing lower extremity edema and ascites, bilateral pulmonary emboli causing shortness of breath, and a right atrial thrombus. 2 He had both tumor thrombus and bland thrombus, with the latter likely related to a hypercoagulable state. Alpha-fetoprotein levels are usually normal. On imaging a heterogeneous mass characterized by hypervascularity and a central scar in the background of normal liver parenchyma is appreciated. Metastatic tumor burden, hepatic adenoma, focal nodular hyperplasia, traditional HCC, and hemangioma are in the differential diagnosis. In contrast to the central scar of focal nodular hyperplasia (FNH), the central scar has low attenuation on T2 images. 3 On biopsy, the presence of large polygonal tumor cells with vesicular nuclei and large nucleoli, eosinophilic granular cytoplasm, and abundant fibrous stroma in thin parallel lamellae around tumor cells support the diagnosis. 1, 4 Immunohistochemistry shows staining for both hepatocellular (Heppar-1) and biliary differentiation (cytokeratin-7 and epithelial membrane antigen), with the latter contrasting FLHCC and HCC. 4 There are limited data on survival stratified by treatment modalities or by disease stage for FLHCC as compared to HCC arising in noncirrhosis livers. In a multicenter study of patients without metastatic disease undergoing resection, the 5-year survival of patients with FLHCC was similar to those patients with HCC without underlying cirrhosis but higher than patients with HCC and concomitant cirrhosis (62% versus 58% versus 27%). 5 Chemotherapeutic options are limited. Given its increased expression in FLHCC, selective targeting of epidermal growth factor receptor may play a role. Modest 5-year survival rates (35%-50% survival rates) after transplantation have been reported. 6

Granular cell ameloblastoma mimicking oncocytoma

Granular cell ameloblastoma is a variant of ameloblastoma where cells located in the central portion of the follicles have granular eosinophilic cytoplasm and the peripheral cells resemble ameloblasts. A case of granular cell ameloblastoma of the mandible having very similar histopathological features of oncocytoma (oxyphilic adenoma) is reported where tumor cells were arranged in cords, sheets and follicles and their cytoplasm was full of eosinophilic granules.

Perivascular Epithelioid Cell Tumor of the Ileum Presenting as Diverticulitis

Perivascular epithelioid cell tumors (PEComas) are a group of rare mesenchymal neoplasms. Gastrointestinal PEComas are exceptionally rare, there being only a few case reports in the literature involving the colon and small intestine. Nearly all PEComas show immunoreactivity for both melanocytic (HMB45 and/or Melan-A) and smooth muscle (actin and/or desmin) markers. A 36-year-old male was admitted to the hospital with acut- abdomen. At laparatomy, a nodular mass protruding from the ileum which clinically simulated a diverticulitis was noticed. Gross examination of the specimen revealed a 2 × 1,5 × 1 cm secondarily ulcerated, solid, nodular, gray white tumor mass in the ileal wall. Histologically, tumor cells were composed of nests of round-polygonal epithelioid cells with abundant clear to slightly eosinophilic granular cytoplasm and round vesicular nuclei. The nests were separated by thin fibrovascular septa. Minimal necrosis and low mitotic activity were noticed in the tumor. Immunohistochemically, tumor cells were positive for SMA, HMB45, and Melan-A and negative for CD10, RCC, CD45, CD117, CD34, EMA, and Desmin. Diagnosis was PEComa of the ileum. We report the case of ileal PEComa to remind the unusual presentation (diverticulitis) of these tumors, besides rarity and diagnostic difficulties.

Granular Cell Tumor Originating from Gallbladder

Granular cell tumors are rare benign tumors that arise from Schwann cells. They are especially rare in the gallbladder; indeed, only four cases have been reported in the English-language literature. This paper reports a granular cell tumor in the gallbladder and is the first such report in a Korean woman. She was admitted to the hospital with jaundice and fever and was diagnosed with acute hepatitis A. While hospitalized, a well-demarcated round mass was incidentally found in her gallbladder. The acute hepatitis A improved with conservative care, but the mass did not change in size after 4 months. The tumor was resected with the gallbladder during laparoscopic surgery, and was found to be a granular cell tumor. The tumor was composed of sheets or irregular fascicles of large polygonal or spindle cells with plump eosinophilic granular cytoplasm that was immunohistochemically positive for S-100 and neuron-specific enolase and negative for neurofilament. (Korean J Med 2012;83:624-628) Keywords: Gallbladder; Biliary tract; Granular cell tumor

Fine Needle Aspiration Cytology of Adrenal Oncocytic Neoplasm of Uncertain Malignant Potential

Sir, Adrenocortical oncocytic neoplasms (AONs) are rare tumors with only about 55 cases reported in the English language literature [1]. Histologic features that predict the biologic behaviour of AONs appear to differ from those of conventional adrenocortical tumors. In 2004, the modified Weiss system was proposed for AONs [2]. A 72-years old male was admitted for evaluation of a palpable abdominal mass. Computer Tomography scan of the abdomen revealed a large heterogeneously enhancing mass lesion arising from the left upper retroperitoneum having clear fat planes with pancreas, spleen and left kidney [Table/Fig-1A]. Possibility of malignant adrenal neoplasm was considered. Image guided Fine Needle Aspiration [FNA] smears were cellular showing singly dispersed polygonal cells with eccentric nucleus and dense granular cytoplasm [Table/Fig-1B]. A few cells were clinging to delicate capillaries in a clean background [Table/Fig-1B] (inset) suggesting a diagnosis of adrenal oncocytic neoplasm. The left adrenalectomy specimen consisted of a 2005 gm solid, encapsulated, globular mass measuring 20 × 15 × 12 cm. Cut surface of the tumor was solid, fleshy tan brown with lobulations of haemorrhage and necrosis [Table/Fig-1C]. The tumor was encapsulated and showed neoplastic cells arranged in a diffuse, solid pattern with multiple foci of haemorrhage, microcystic degeneration and necrosis [Table/Fig-1D]. Tumor cells were uniform with abundant brightly eosinophilic granular cytoplasm, round to oval vesicular nucleus. Mitotic figures, capsular and venous invasion were absent. A final diagnosis of adrenal oncocytic tumor of uncertain potential was given based on modified Weiss Criteria. Electron Microscopy confirmed the oncocytic nature of cells. [Table/Fig-1] [Table/Fig-1]: (1A) - CT scan showing a large well defined mass with heterogenous echotexture; (1B) - Smear showing singly dispersed cells with eccentric nucleus and granular cytoplasm (PAP 40X); (1B inset) - Smear showing tumor cells attached to delicate ... AONs have the potential to behave in a benign fashion, recur or extensively infiltrate into the adjacent organs. Average age at diagnosis is 47 years (range 6-77) with a slight female predilection [3]. Size varies from 2.2 to 20 cm and weight from 8 to 1900 g [1]. In our case the tumor weighed 2005 gm which is the highest so far reported. Imaging characteristics of adrenal oncocytic tumors are described as single case reports . Fibrous encapsulation and heterogeneous areas do not differentiate between benign and malignant oncocytic tumors [4]. Cytopathologic diagnosis of AONs by FNA is described by some authors.[5] Some of the criteria of Modified Weiss system like necrosis and atypical mitosis can be evaluated on cytology. Unfortunately accurate mitotic count, venous invasion and capsular invasion can not be assessed in smears. In the absence of major criteria, it is best to designate the tumor as an oncocytic adrenal neoplasm with a note for a detailed histopathologic assessment. If any minor criteria are present, designation AON of uncertain malignant potential may be rendered. In our case there was no necrosis or atypical mitosis on smears. However due to the large size and heterogeneous areas on CT scan, possibility of malignancy was still considered preoperatively. Only after detailed histopathologic examination, it was designated AON of uncertain malignant potential. Awareness of Modified Weiss criteria will help in averting over diagnosis of malignancy while dealing with FNA of AON.

Oncocytic carcinoma of lip: A rare neoplasm of minor salivary gland

Oncocytic carcinoma is an extremely rare neoplasm of the salivary gland, with only a few cases reported in literature till date. We report the occurrence of this rare lesion in lip in a 43-year-old female presenting with a progressively increasing swelling for which excision was done. Fine needle aspiration was done and the smears revealed tumor cells with well-defined cell borders, round to oval, central to eccentrically located moderately pleomorphic nuclei with fine chromatin, prominent nucleoli and abundant eosinophilic granular cytoplasm. Microscopic examination of the resected tumor showed solid sheets, nests, islands and cords of oncocytic cells diffusely infiltrating the surrounding tissues. After 5 months, the patient again presented with bilateral submandibular and right axillary lymphadenopathy revealing metastatic deposits from oncocytic carcinoma. We report this case of oncocytic carcinoma because of its unusual location, the minor salivary gland of lip being a rare site for the tumor.

Oncocytoma of the adrenal gland medulla

We report an unprecedented case of an oncocytoma of the adrenal gland medulla in a 61-year-old woman. The patient presented with right flank pain and hematuria. Computed tomographic studies revealed a right adrenal gland mass that measured 2 cm, which was subsequently excised laparoscopically. Grossly, the tumor in the medulla measured 1.9 × 1.2 cm, weighed 5 g, and had a solid tan-brown cut surface. Histologically, it consisted of large tumor cells containing eosinophilic granular cytoplasm arranged in trabecular and nodular patterns. Electron microscopy revealed closely packed mitochondria in the cytoplasm of almost all tumor cells. The tumor cells were immunohistochemically positive for vimentin. The patient resumed usual activities 2 weeks after surgery, and at 6-month follow-up, she is doing well.

Multiple Cutaneous Granular Cell Tumors: Case Report of a 19-Year-Old African American Female

This is a somewhat rare case of a 19-year-old African American female with multiple cutaneous granular cell tumors. Granular cell tumors are of neural origin, except in rare cases, and are considered benign, with a low incidence of malignancy. The clinical presentation varies greatly, but these tumors are most commonly painful and slow growing, with two-thirds occurring on the head and neck. Patients are most commonly in their second to fourth decades of life, two-thirds are black, and two-thirds are women. Granular cell tumors are diagnosed by the characteristic pathologic findings of polygonal cells with eosinophilic granular cytoplasm. These tumors are most commonly singular but can be multiple in 10 to 15% of patients. Older patient age, rapid growth or enlargement, and a history of local recurrence should raise concern for malignant behavior. The distribution and family history in this case are suggestive of possible mosaicism.

Extrapancreatic Solid Pseudopapillary Neoplasm

Solid pseudopapillary neoplasm, an uncommon, intriguing, low-grade malignant tumor of the pancreas, can exceptionally occur in extrapancreatic sites. We report 1 such case occurring as an ovarian primary in a 25-year-old woman, who presented with abdominal fullness. She remained well 12 years after resection of the 1.7-kg right ovarian tumor. Histologically, the tumor showed a solid, dehiscent, and pseudopapillary growth, traversed by fibrous septa and arborizing blood vessels. The polygonal tumor cells had round nuclei, fine chromatin, and lightly eosinophilic granular cytoplasm. In certain areas, eosinophilic hyaline globules were present. On immunostaining, the tumor cells were positive for β-catenin (nuclear translocation), CD10, CD56, and synaptophysin (focal), and were negative for cytokeratin, E-cadherin, and chromogranin. The morphologic and immunohistochemical features were compatible with those of solid pseudopapillary neoplasm. Review of the literature uncovered 10 cases of extrapancreatic solid pseudopapillary neoplasm with adequate data for analysis. They were seen to occur predominantly in young female patients, who presented with a large tumor mass, similar to their pancreatic counterparts. The most common sites of occurrence were the mesocolon (with ectopic pancreatic tissue) and ovary. Awareness of the existence of this tumor in various extrapancreatic sites is essential to avoid misdiagnosis.

An Unusual Cause of Pancreatitis

Question: A 51-year-old man presented with severe epigastric abdominal pain, an amylase of 171 U/L (normal, 25–115) and lipase of 3365 U/L (normal, 114–286). Computed tomography (CT) of the abdomen and pelvis demonstrated localized heterogenous hypoattenuation in the tail of the pancreas (TOP) with adjacent inflammatory changes consistent with acute pancreatitis with no evidence of gallbladder disease. He denied alcohol use, had a normal serum triglyceride level, and was treated conservatively for acute pancreatitis of unclear etiology. Follow-up magnetic resonance imaging demonstrated a subtle, 1.1 × 1.4-cm TOP mass with an appearance suggestive of a neuroendocrine tumor (Figure A). Positron emission tomography/CT failed to show any evidence of F-18 fluorodeoxyglucose avid malignant disease. On endoscopic ultrasound (EUS) examination performed 4 months later, a slightly hypoechoic TOP mass was demonstrated (Figure B; upper panel, arrow denoting pancreatic duct (PD) with an adjacent upstream area of hypoechoic, lobulated and atrophic pancreas). There was a sharp demarcation between the abnormal parenchyma upstream of the mass and the normal parenchyma downstream of the mass (Figure B, lower panel). The splenic vein seemed to be encased by the TOP mass. The remainder of the EUS examination was unremarkable. The mass was sampled with a 25-gauge fine needle aspiration (FNA) revealing a highly cellular smear of epithelial cells with acinar features, including granular eosinophilic cytoplasm, round to oval nuclei and mild anisonucleosis (Figure C, left inset). The patient underwent a distal pancreatectomy with splenectomy (Figure C, right inset). What is the etiology of the pancreatitis? See the Gastroenterology web site (www.gastrojournal.org) for more information on submitting your favorite image to Clinical Challenges and Images in GI. Histologic examination of the surgical specimen demonstrated a 1.1-cm nodule of granular eosinophilic cytoplasm with centrally placed nuclei consistent with oncocytic metaplasia surrounded by nodules of acinar cells and focal pancreatitis (Figures C). There was no evidence of acinar cell or ductal carcinoma. The decision to operate was based upon the false-positive high suspicion of acinar cell carcinoma from the initial EUS-FNA. Oncocytic metaplasia is characterized by the conversion of epithelial cells into relatively larger cells with abundant eosinophilic granular cytoplasm due to an abundance of mitochondria.1Hamperl H. Benign and malignant oncocytoma.Cancer. 1962; 15: 1019-1027Crossref PubMed Scopus (286) Google Scholar The cause and significance of oncocytic differentiation are subjects of debate. Oncocytes may represent mild cellular degeneration with loss of specialized function as a result of age and cellular “burnout.”1Hamperl H. Benign and malignant oncocytoma.Cancer. 1962; 15: 1019-1027Crossref PubMed Scopus (286) Google Scholar Oncocytes have been described in the normal state of health in most organs, including the stomach, hepatobiliary tract, pancreas, and colon.2Chang A. Haragwi S. Oncocytes, oncocytosis and oncocytic tumors.Pathol Ann. 1992; 27: 263-304Google Scholar Tumors composed of oncocytes occur most commonly in salivary, thyroid, and parathyroid glands, and in the kidneys. There are <30 reports of oncocytic lesions of the pancreas, of which 6 describe nonendocrine lesions, as in our case.3Volante M. La Rosa S. Castellano I. et al.Clinico-pathological features of a series of 11 oncocytic endocrine tumours of the pancreas.Virchows Arch. 2006; 448: 545-551Crossref PubMed Scopus (30) Google Scholar To our knowledge, this is the first reported case of a patient with pancreatitis caused by an oncocytoma of the pancreas. Pancreatic oncocytomas with endocrine features follow a more malignant course, whereas nonendocrine types tend to be more benign.3Volante M. La Rosa S. Castellano I. et al.Clinico-pathological features of a series of 11 oncocytic endocrine tumours of the pancreas.Virchows Arch. 2006; 448: 545-551Crossref PubMed Scopus (30) Google Scholar Several EUS findings suggested that this oncocytoma was the likely cause of the localized pancreatitis. The main PD was of equal diameter downstream and upstream of the mass (rather than the typical gradual tapering to a smaller caliber as it is followed to the distal TOP; Figure B). This suggested a relative dilation of the PD in the TOP, likely owing to compression of the PD by the downstream mass with resultant parenchymal changes abruptly beginning just upstream of the mass. Surgical pathology demonstrated a focus of pancreatitis adjacent to the oncocytoma. Postoperatively, the patient had no further episodes of pancreatitis and no evidence of disease recurrence at 2-year follow-up. This case highlights a previously undescribed cause of pancreatitis.

Cytologic, histologic, and immunohistochemical features of lingual liposarcoma in a dog

A 9-year-old female spayed mixed-breed dog was presented to the referring veterinarian with a history of decreased appetite and difficulty with prehension and swallowing because of a firm oval mass in the tongue. On cytologic evaluation of a fine-needle aspirate of the mass there were numerous round to polygonal cells organized individually or in loose clusters with rare branching capillaries. The cells had eosinophilic granular cytoplasm, round to oval nuclei, and occasionally indistinct borders. The cytologic diagnosis was granular cell tumor (GCT) of the tongue. Impression smears of a biopsy sample of the lingual mass contained similar eosinophilic granular cells with variable numbers of clear vacuoles in the background, numerous perivascular arrangements, and occasional lipoblasts, suggestive of liposarcoma. On histologic examination the tumor was composed of numerous lipocytes with rare foci of round eosinophilic granular cells without evidence of vacuolation; occasionally, atypical mitotic figures were seen. Immunohistochemically, the cells were uniformly negative for periodic acid-Schiff and did not express smooth muscle actin, desmin, or cytokeratin but were immunoreactive for vimentin and S100. A diagnosis of well-differentiated liposarcoma was made on the basis of morphologic and immunohistochemical results. Eosinophilic granular cells may be a component of well-differentiated liposarcoma and are not limited to GCT. Liposarcoma should be considered in the differential diagnoses of lingual tumors in the dog when cytological evaluation reveals eosinophilic granular cells consistent with GCT.

Renal carcinoma with (6;11)(p21;q12) translocation: Report of an adult case

An extremely rare adult example of renal carcinoma with t(6;11)(p21;q12 or q13) is presented here. The tumor of a 45-year-old Japanese male, excised under the diagnosis of renal cell carcinoma, was a well circumscribed 7 cm mass with light brown sectioned surfaces. Histologically, it was composed of a major population of large polygonal epithelioid cells in a nested alveolar growth and a subpopulation of smaller cells clustering around hyaline basement membrane material. The former cells possessed ample, clear to eosinophilic granular cytoplasm with well-defined cell borders and the latter was frequently accompanied by psammomatous calcification. These tumor cells exhibited immunoreactivity for melanoma markers, transcription factor EB and cathepsin K, but were not reactive for epithelial markers and transcription factor E3. While pulmonary metastatic foci that were noted preoperatively progressed rapidly following interferon-based therapy, subsequent sunitinib malate yielded a partial response and stabilized the lung metastasis for 6 months after surgery. We could trace 20 cases of 6p21 translocation renal carcinoma, among which only four were in individuals older than 40 years. Description of a new case like this is important since little is known about the prognosis and treatment of adult patients with this condition.

Two Cases of Eosinophilic Variant Chromophobe Renal Cell Carcinoma, with a Rare Association of Right Atrial Myxoma in One of them

Chromophobe renal cell carcinoma is a relatively uncommon variant of renal cell carcinoma. Eosinophilic variant of chromophobe renal cell carcinoma (EVCRCC) is still less frequent and is composed predominantly of small to medium-sized cells with abundant granular eosinophilic cytoplasm. We report two cases of EVCRCC, with one having a rare association of right atrial myxoma. We present these cases, due to the rarity of EVCRCC and an unusual association of right atrial myxoma in one of them. Both patients recovered well after surgery, with no recurrence or metastasis after 2 years of follow-up.

Adenoendocrine cell carcinoma of the extrahepatic bile duct: a case report and review of the literature.

Extrahepatic bile duct cancer with an endocrine cell component has rarely been reported. We report here on a case of adenoendocrine cell carcinoma in the middle bile duct. An 82-year-old man was admitted to hospital for jaundice and anorexia. Computed tomography and magnetic resonance imaging examination showed a papillary low-density mass in the middle bileduct. Endoscopic retrograde cholangiography showed obstruction of the bile duct, and blushing cytology of the bile duct revealed an adenocarcinoma. We resected the extrahepatic bile duct with regional lymph node dissection. A pathological examination revealed a neuroendocrine component showing small cytoplasmic cells with hyperchromatic nuclei and a rosette-like structure in the middle of the tumor. In the peripheral mucosal region, there was a well-differentiated adenocarcinoma composed of columnar and cuboidal epithelial cells with clear and slightly granular eosinophilic cytoplasm. Immunohistochemical analysis showed positive staining for CD56, following the diagnosis of adenoendocrine cell carcinoma. The Ki-67 rate was >30% suggesting a small-cell endocrine carcinoma. The adenocarcinoma component infiltrated into the endocrine component, and some of the endocrine component was positive for cytokeratin, suggesting transdifferentiation of the adenocarcinoma into the endocrine component rather than originating from the common precursor cell. The patient experienced liver metastasis 3months after the operation and died 6months after the operation. Adenoendocrine tumor of the bile duct is extremely rare and adjuvant chemotherapy is necessary according to the malignant potential of the neuroendocrine tumor rather than the adenocarcinoma.

Perivascular Epithelioid Cell Tumors (PEComas) of the Head and Neck: Report of Three Cases and Review of the Literature

PEComas are a family of neoplastic lesions that share overlapping morphology, immunohistochemistry, and ultrastructure that include angiomyolipoma, lymphangioleiomyomatosis, clear cell "sugar" tumor of the lung as well as similar tumors occurring in a variety of visceral, cutaneous and soft tissue sites throughout the body. The defining histopathological features are epithelioid cells with a perivascular distribution containing clear to pale eosinophilic granular cytoplasm and a round-to-oval centrally located nucleus with an inconspicuous nucleolus. Immunohistochemically, coexpression of melanocytic (HMB-45 and/or Melan-A) and myoid markers are characteristic. In the present study, we describe three PEComas occurring in the head and neck (nasal cavity and larynx) and discuss the behavior of these distinctive tumors and review the literature of head and neck PEComas. The importance of recognizing this entity will ensure its consideration in the differential diagnosis of tumors of the head and neck with a similar morphology. The histogenesis of PEComas still remains elusive and additional cases with a prolonged follow up remain important to accurately determine the behavior of these distinctive tumors. Complete surgical excision still remains the treatment of choice for histologically benign PEComas.

Adrenal perivascular epithelioid cell tumor: a case report with discussion of differential diagnoses.

A 50-year-old man presented with nausea and abdominal bloating sensation of a few months' duration and was found to have a large adrenal mass that was resected after computed tomography scan evaluation. The histopathologic examination showed epithelioid and spindle cells having clear to granular eosinophilic cytoplasm, and small, central, round to oval nuclei with small nucleoli. The tumor cells demonstrated reactivity for smooth muscle actin, HMB-45, Melan-A, and vimentin, with focal positivity for desmin and S100 protein and negative staining for inhibin, synaptophysin, and chromogranin. A diagnosis of perivascular epithelioid cell tumor was made. Perivascular epithelioid cell tumors can arise in a variety of locations, including omentum/mesentery, female genital tract, pelvic soft tissues, skin, and falciform ligament, but an adrenal primary tumor has not been previously reported, to the best of our knowledge. The differential diagnosis is broad and site-dependant and in our case includes several neoplasms with clear cells that can involve the adrenal gland, including a primary adrenocortical neoplasm. A review of the related literature and discussion of the differential diagnoses are presented.

Adrenal Perivascular Epithelioid Cell Tumor: A Case Report With Discussion of Differential Diagnoses

A 50-year-old man presented with nausea and abdominal bloating sensation of a few months' duration and was found to have a large adrenal mass that was resected after computed tomography scan evaluation. The histopathologic examination showed epithelioid and spindle cells having clear to granular eosinophilic cytoplasm, and small, central, round to oval nuclei with small nucleoli. The tumor cells demonstrated reactivity for smooth muscle actin, HMB-45, Melan-A, and vimentin, with focal positivity for desmin and S100 protein and negative staining for inhibin, synaptophysin, and chromogranin. A diagnosis of perivascular epithelioid cell tumor was made. Perivascular epithelioid cell tumors can arise in a variety of locations, including omentum/mesentery, female genital tract, pelvic soft tissues, skin, and falciform ligament, but an adrenal primary tumor has not been previously reported, to the best of our knowledge. The differential diagnosis is broad and site-dependant and in our case includes several neoplasms with clear cells that can involve the adrenal gland, including a primary adrenocortical neoplasm. A review of the related literature and discussion of the differential diagnoses are presented.

Nasopharyngeal Oncocytoma in a Cat

A 5-year-old male neutered Siamese cat was referred because of nasal swelling, nasal discharge, and oral respiration. Computed tomography and necropsy following euthanasia revealed a firm tan mass in the nasopharynx, occluding the nasal passage. Histologically, the nasopharyngeal mass was composed of solid nests, anastomosing cords, and closely packed glands separated by a delicate fibrovascular stroma. Individual neoplastic cells were cylindrical to polyhedral in shape, had distinct cell borders, and contained moderate amounts of finely granular eosinophilic cytoplasm and round to oval nuclei. The cytoplasmic granules were positive on phosphotungstic acid-hematoxylin staining. Immunohistochemically, the neoplastic cells were positive for cytokeratin and negative for chromogranin A, neuron-specific enolase, and vimentin. Ultrastructurally, the neoplastic cells contained numerous mitochondria.