Epithelial-myoepithelial carcinoma of parotid gland: a case report with immunohistochemical and ultrastructural studies

A 66-year-old man presented with a painless mass of the parotid gland. Light and electron microscopic studies verified the basic nature of the tumor as epithelial-myoepithelial carcinoma, a low-grade malignant neoplasm of the salivary gland. Pathologically, there were two types of cells; the inner eosinophilic epithelial cells lining the ducts and the outer clear cells. The former cells displayed immunoreactivity for cytokeratin and ultrastructural features of apical microvilli and desmosome. The latter cells were positive for actin, S-100 protein, vimentin and the cytoplasm contained actin microfilaments. Such pathological findings were characteristic features of this rare tumor. To our knowledge, this is the first reported case of EMC in Thailand.     

Results of the surgical management and histopathological evaluation of 88 parotid gland Warthin''s tumours

With the introduction of parotidectomy after identification of the facial nerve the recurrence rates for benign tumours has declined rapidly. Subsequently, attention was focused on other sequelae of parotid surgery. To reduce the specific surgical morbidity, several modifications of parotidectomy have been implemented. This study compares the results of the different surgical techniques with regard to the histopathological findings and recurrence rate for Warthin's tumour of the parotid gland. Eighty-eight primary surgical parotid procedures were performed on 85 patients for a Warthin's tumour. The surgical procedures included 52 'partial' superficial parotidectomies, 22 'standard' superficial parotidectomies, 12 partial superficial/deep lobe parotidectomies, and two 'selective' deep lobe parotidectomies. No patient developed a recurrence or experienced permanent facial nerve paresis/paralysis, the median follow-up being 93 months. Histopathological examination revealed a multifocal origin in 23% (20/88) of the surgical specimens. Partial parotidectomy is an effective treatment for Warthin's tumour. There is no need for extended follow-up.     

Mucoepidermoid carcinoma of the parotid gland: a rare presentation in a young child

Although mucoepidermoid carcinoma (MEC) is the most common malignant salivary gland neoplasm in childhood and adolescence, it is rarely found in children under the age of 10. A 6-year-old girl had an asymptomatic neck mass for 5 months. Clinical examination findings showed a 1.5-cm smooth and firm but mobile nontender mass located in the upper left anterior cervical triangle, clinically separate from the parotid gland. Ultrasound examination findings showed a vascular mass, with a cystic component, possibly within the tail of the parotid gland. An excisional biopsy was performed and frozen section showed a low-grade MEC. A left superficial parotidectomy was then performed. Final histopathologic examination showed one positive resection margin. Subsequently, reexcision of the surgical site and an upper modified neck dissection was undertaken. This unusual presentation of MEC as a neck mass in one of the youngest reported patients illustrates that the anatomic region for parotid tumors is large. Possibly some of these tumors may arise from heterotopic or accessory parotid tissue.     

Perineurioma with ossification: a case report with immunohistochemical and ultrastructural studies

We evaluated the elbow flexion test in 216 elbows without compression of the ulnar nerve at the cubital tunnel and without other neuropathies. We used Rayan's four positions as our test. The percentage of positive tests was only 3.6% at one minute, whereas evaluating the responses at three minutes we saw positive results in 16.2%. Therefore we find that if the test is performed for one minute it may be useful to help in diagnosing ulnar nerve compression at the cubital tunnel.     

Neuroblastoma of parotid gland: report of a case and immunohistochemical characteristics

A case of a parotid mass in a 2-year-old boy, postoperatively diagnosed as neuroblastoma, a rare tumour not previously reported in the parotid gland is presented. The neoplasm developed within the parotid gland as a painless mass without regional lymphadenopathy. Histopathologically, the tumour showed primitive nerve cells-neuroblasts-with round or oval dark basophilic nuclei and scanty cytoplasm. The cells were arranged in circular rosettes around an eosinophilic mass consisting of very fine filaments originating in the tumour cells or papillary configuration and sometimes scattered in the poorly developed stroma. Immunohistochemical evaluation of the tumour showed a positive immunoreactivity for vimentin, alpha and beta subunits of S-100 protein, neurone-specific enolase (NSE), substance P, met-enkephalin and chromogranin but cytokeratins, desmin, actin, myosin, glial fibrillary acidic protein (GFAP) and calcitonin gene related peptide (CGRP) were negative. The histopathological and immunohistochemical findings conclude a diagnosis of neuroblastoma of the parotid gland.     

Solitary fibrous tumour: clinicopathological, immunohistochemical, and ultrastructural analysis of 12 cases arising in soft tissues, nasal cavity and nasopharynx, urinary bladder and prostate

Heart-rate variability (HRV), a measure of fluctuation around the mean heart rate, reflects the sympathetic and parasympathetic balance of the autonomic nervous system, and is an excellent technique to study cardiovascular tone in patients with neurological injuries. The purpose of this study was to determine whether abnormal HRV is present in patients with traumatic brain injury (TBI) during the post-acute recovery phase. Using a prospective, case/control design, we performed 24-h ambulatory ECG monitoring in seven TBI patients and in seven controls (C). There was a significant difference in root mean squared successive difference of RR intervals (C 40.4 +/- 10.3, TBI 23.3 +/- 16.5, p = 0.04) between TBI and C. Four patients with TBI (compared to one control) had abnormal standard deviation of the RR interval. When these four patients were compared to their matched controls, significant differences were found in frequency domain measure (In total power: TBI 4.4 +/- 0.9 ms2, C 7.1 +/- 1.4 ms2, In low frequency: TBI 3.3 +/- 1.1 ms2, C 6.4 +/- 1.4 ms2; In high frequency TBI 2.0 +/- 1.0 ms2, C 4.8 +/- 1.3 ms2, all p < 0.05). Thus, abnormalities in both time and frequency domains of HRV are present in TBI during the post-acute recovery phase.     

A histopathological, ultrastructural and immunohistochemical study of congenital hereditary retinoschisis

OBJECTIVE: To confirm our earlier histopathological and electron microscopic findings in congenital hereditary retinoschisis (CHRS) in two additional globes and to further evaluate the nature and origin of the intraretinal filaments by means of immunohistochemical analysis. PATIENTS: Three white men with CHRS, aged 83 years (patient I) (two globes), 55 years (patient 2) (two globes) and 33 years (patient 3, nephew of patient 2) (one globe). OUTCOME MEASURES: Findings on histopathological study and electron microscopy (patient I) and immunohistochemical analysis (all five globes). RESULTS: Histopathological examination showed extensive extracellular deposition of amorphous material positive for periodic acid-Schiff reagent in the outer schisis layer and focally in the macula. Ultrastructurally, the amorphous material represented filaments measuring 8 to 12 nm in diameter within degenerated Müller cells, with accumulation of these filaments in adjacent extracellular spaces. Similar, less severe changes were seen in the superonasal retina. Immunohistochemical studies showed focal reactivity for glial fibrillary acidic protein (GFAP) in the retina adjacent to the schisis cavity in all five globes, focal reactivity for S-100 protein in four retinas, rare focal staining for vimentin and neurofilaments in two retinas each and no reactivity for type I keratin or actin. CONCLUSIONS: The present study corroborates our previous work and provides pathological evidence that the retinal disorder extends beyond the limits of the schisis. The results of the immunohistochemical analysis are consistent with a glial cell origin of the filaments. We postulate that defective Müller cells produce GFAP and possibly S-100 protein, which accumulate within the retina and secondarily result in degeneration of these cells and schisis formation.     

Nontyrosine crystalloids in fine-needle aspiration specimens of the parotid gland: a report of two cases and review of the literature

Transitional-cell carcinoma is the dominant histological type of malignant tumors of the urinary bladder. There is limited information on risk factors for non-transitional-cell carcinoma (NTCC) of the bladder. We used data from 9 case-control studies on bladder cancer from 6 European countries to examine the association between NTCC, tobacco smoking and occupation. Information on 146 cases diagnosed with NTCC were matched by age, gender and study center to 727 non-cancer population or hospital controls and also with 722 transitional-cell-bladder-cancer controls. Lifetime smoking and occupational history were evaluated. A statistically significant excess risk for NTCC was observed for current smoking [odds ratio (OR) = 3.61, 95% confidence interval (CI) 2.08-6.28]. The risk increased with higher tobacco consumption (OR for highest tertile of pack-years = 7.01, 95% CI 3.60-13.66). The risks were higher for squamous-cell carcinomas than for other types of NTCC. Among major occupational groups, a significant excess risk was seen for field-crop and vegetable-farm workers (OR = 2.06, 95% CI 1.03-4.10). These results indicate that NTCC of the bladder is associated with smoking and specific occupations. The risk pattern seems to differ, in part, from that observed for transitional-cell carcinoma of the bladder.     

Cystadenolymphoma of the parotid gland an immunohistochemical study of the epithelial component of twenty cases

Carcinoembryonic antigen, epithelial membrane antigen, Keratin, Desmin, Vimentin, CD30, lysozyme, alpha 1-antitrypsin, alpha 1-antichymotrypsin, S-100 protein, somatostatin and glucagon were looked for using immunohistochemical methods in the epithelial component of 20 parotid gland cystadenolymphomas and 20 normal parotid glands. Carcino-embryonic antigen, ephithelial membrane antigen, S-100 protein, and somatostatin were found in the epithelial cells of most of the cystadenolymphomas. In normal parotid tissue, carcinoembryonic antigen, epithelial membrane antigen, Keratin, alpha 1-antitrypsin, alpha 1-antichymotrypsin, and S-100 protein were found in all three types of ductal cells, somatostatin only in intercalated and striated ductal cells, and lysozyme only in acinar and intercalated ductal cells. Desmin and CD30 were found in the epithelial component of seven of the 20 tumors versus none of the 20 normal parotid glands. Glucagon and Vimentin were negative both in tumor epithelial cells and in normal parotid ductal cells. Our results support the theory that cystadenolymphomas arise from epithelial cells. The presence of lysozyme in the epithelial tumor cells and in the intercalated ductal cells of normal parotid tissue suggest that cystadenolymphomas may arise from the intercalated ducts. The presence of S-100 and somatostatin may indicate that the tumor derives from neuroendocrine structures, but further studies are needed to clarify this point.     

Cytodifferentiation of atypical adenomatous hyperplasia and bronchioloalveolar lung carcinoma: immunohistochemical and ultrastructural studies

We used immunohistochemistry and electron microscopy to evaluate the differentiation of cells comprising atypical adenomatous hyperplasia (AAH; n = 26), early bronchioloalveolar lung carcinoma (BAC; n = 11), and overt BAC (n = 16), which are assumed to constitute a continuous spectrum of developmental steps of BAC. Surfactant apoprotein (SAP), a marker for type 2 alveolar cells, was expressed in cells from all the lesions of AAH, early BAC, and overt BAC. However, the proportion of SAP-positive cells decreased and their distribution became more heterogeneous with advancing lesion grade. Urine protein 1, which is identical to the Clara cell-specific 10 kDa protein, was expressed in 70% of overt BAC, whereas only 20% of early BAC showed weak reactivity and none of AAH lesions showed any reactivity at all. Ultrastructurally, type 2 alveolar cell differentiation was predominant among cells from AAH and early BAC. Our results suggest that precursor cells of BAC differentiate predominantly towards type 2 alveolar cells. Cells comprising overt BAC retain this differentiation phenotype, but to a reduced extent. In contrast, concomitantly with progression, cells with Clara cell differentiation emerge and their proportion increases. Such phenotypic changes may reflect metaplasia occurring in tumour cells during the development of BAC.     

Adenosquamous carcinoma of the tongue: report of a case with histochemical, immunohistochemical, and ultrastructural study and review of the literature

The histologic examination of dental implants retrieved from humans is important to establish the causal determinants of implant failure, and to compare and validate the results obtained from animal studies. This study presents a retrospective review of the histologic features of 230 implants retrieved in an 8-year period (1989-1996). All the implants were treated to obtain thin (20 to 30 microm) ground sections. The majority of implants were retrieved because of mobility (n=56), peri-implantitis (n=54), or fractures (n=90). Peri-implantitis occurred more frequently before (n=44) than after (n=10) abutment connection. A dense fibrous connective tissue with no inflammatory cells was present at the interface in the implants retrieved for mobility; bone was found only in the most apical part. In many of these implants epithelial cells were present. The main histologic features of peri-implantitis consisted of the presence of a bone sequestrum near the implant, many bacteria present on the implant surface, and an inflammatory infiltrate (macrophages, lymphocytes, and plasma-cells) nearby. Histology showed that in the implants removed for fracture, there was a very high percentage (80 to 100%) of peri-implant bone.     

Melanotic neuroectodermal tumour of infancy: an immunohistochemical and ultrastructural study

Two cases of melanotic neuro-ectodermal tumour of infancy (MNTI)--a rare neoplasm arising in the first year of life--are reported, with the results of immunohistochemical and ultrastructural examination. The tumours consisted of a biphasic cell population in a fibrous stroma. The small, darkly staining cells comprising the first population stained positively for synaptophysin, showing them to be neuroblasts, and the large epithelioid cells comprising the second cell population stained positively with the antibodies HMB-45 and NKI-Beteb, showing them to be melanocytes. Ultrastructural examination of the second case confirmed the biphasic nature of the tumour cells, with secretory granules and neurofilaments in the neuroblastic population, and melanosomes in the epithelioid population. These results add to the evidence supporting the neural crest origin of MNTI and confirm its formation from two distinct cell lines. Both cases have responded to local excision, with no recurrence more than a year after initial treatment.     

Deletion of the p16 gene and microsatellite instability in carcinoma arising in pleomorphic adenoma of the parotid gland

Dogs and cats with cancer have significant alterations in carbohydrate, protein, and fat metabolism, which can result in cancer cachexia and subsequently can decrease quality of life, reduce response to therapy, and shorten survival time. Nutritional modulation may be beneficial in the treatment of cancer patients to reverse these metabolic alterations. There is evidence that foods relatively low in simple carbohydrates with moderate amounts of high-quality protein, fiber, and fat (especially fats of the omega-3 fatty acid series) are beneficial for pets with cancer. In addition, certain supplemental nutrients may have potential to reduce the risk of developing cancer, or the growth and metastases of established malignant disease. Nutritional intervention can be a powerful tool for controlling malignant disease and for reducing toxicity associated with chemotherapy and radiation therapy.     

Mucoepidermoid carcinoma of the pancreas: report of a case

We present herein the case of a 64-year-old man diagnosed as having a mucoepidermoid carcinoma of the pancreas. The tumor originated in the tail of the pancreas and invaded the spleen, left adrenal gland, left kidney, and transverse colon. Liver and peritoneal metastases were also noted. Despite surgical treatment and adjuvant chemotherapy, the disease progressed rapidly and the patient died of cachexia 4 months after his initial diagnosis. Mucoepidermoid carcinoma of the pancreas is a rare entity, and is believed to be a form of adenosquamous carcinoma known as adenoacanthoma. However, in this patient, no differentiated squamous cell component could be detected. In fact, the tumor was composed of mucin-producing cells, epidermoid cells, and intermediate cells. Immunohistochemical staining for the carcinoembryonic antigen, CA19-9, and SPan-1 demonstrated a production of cancerous mucin in the epidermoid cells, suggesting that mucoepidermoid carcinoma may arise from the squamoid metaplasia of an adenocarcinoma.     

Sarcomatoid carcinoma of the small intestine: histologic, immunohistochemical and ultrastructural features of three cases and its differential diagnosis

Three cases of sarcomatoid carcinoma of the small intestine are presented. One of them was found accidentally in the duodenum of a patient with a well differentiated adenocarcinoma and a malignant lymphoma that were limited to the stomach. The other two cases arose from the ileum. All of the tumors were whitish, soft and ulcerated with focal hemorrhage and necrosis and showed expansive growth. Each tumor consisted of a mixture of polygonal and spindle shaped anaplastic neoplastic cells arranged in sheet, short fascicular or haphazard fashion, with no finding suggesting epithelial differentiation. Special stains demonstrated intracellular mucin in only a small number of tumor cells in two cases, but not in the other case. Immunohistochemically, the tumor cells of two cases at both primary and metastatic sites showed a positive immunoreaction for cytokeratin and epithelial membrane antigen. In the other case, only a few tumor cells at the metastatic site, but not at the primary site, showed cytokeratin positivity. Various numbers of tumor cells positive for vimentin, alpha-1-antitrypsin (AAT), alpha-1-antichymotrypsin (ACT) and KP-1 were detected in each case. Ultrastructurally, some populations of tumor cells possessed various amounts of tonofilaments with a few intercellular connections between adjacent tumor cells. These cases should be classified as sarcomatoid carcinoma of the small intestine, despite partial or complete loss of epithelial features, and distinguished from the various sarcomas.     

Malignant rhabdoid tumor of the vulva: case report with cytological, immunohistochemical, ultrastructural and DNA ploidy studies and a review of the literature

A case of malignant rhabdoid tumor of the vulva in a 25-year-old female was examined. The patient presented with a subcutaneous nodule in the left labium majus. Smears of the material obtained by percutaneous fine-needle aspiration demonstrated clusters of atypical cells with prominent nucleoli. The tumor measured 6 x 5 x 5 cm and appeared tan to brown on the cut surface and partly cystic. Pathological findings obtained from intraoperative frozen tissue sections had been originally interpreted as rhabdomyosarcoma. Light microscopic examination revealed that polygonal tumor cells having vesicular nuclei with prominent nucleoli were arranged in sheets and the great majority of the tumor cells contained an eosinophilic globular paranuclear cytoplasmic inclusion. Ultrastructurally, this cytoplasmic inclusion corresponds to whirls of intermediate filaments. Vimentin immunoreactivity was detected in both the cytoplasm and cytoplasmic inclusion of almost all the tumor cells. No cytokeratin and desmin immunoreactivity were detected in the tumor cells. The Ki-67 labeling index was 36% and the DNA content of the tumor cells, which was examined by image cytometry, demonstrated diploidy (DNA index = 0.95).     

Rhabdomyosarcoma mimicking acute leukemia in an adult: report of a case with histologic, flow cytometric, cytogenetic, immunohistochemical, and ultrastructural studies

OBJECTIVES: To measure ground reaction force variables during lameness resulting from impaired tibial nerve function and to determine whether these variables changed significantly as recovery progressed. ANIMALS: 11 healthy Greyhounds of either sex, weighing between 22 and 39 kg. PROCEDURE: On 3 consecutive days before surgery, ground reaction forces were measured by force platform gait analysis at the trot. In dogs under general anesthesia, the left tibial nerve was crushed proximal to innervation of the gastrocnemius muscle. Gait analyses were repeated on days 8 to 10, 28 to 30, 43 to 45, 58 to 60, and 90 to 92 after surgery. Ground reaction force variables and stance time were compared among the 3-day clusters. RESULTS: 10 days after surgery, all dogs had weight-bearing lameness attributed to paralysis of muscles in the caudal compartment of the crus. Nerve regeneration resulted in functional recovery within 3 months. Decreases in vertical force were significant 10 days after surgery; thereafter, changes reflected gradual return of load bearing, with the most marked improvement between 10 and 45 days. At 90 days, vertical force variables were within 3% of presurgical values. Stance time for the left hind limb was significantly longer at 10, 30, and 45 days after surgery and was seen in all dogs, but returned to within 1 % of preoperative stance time at 90 days. The effect of tibial nerve dysfunction on braking or propulsive force was not significant. CONCLUSIONS AND CLINICAL RELEVANCE: The significant changes in vertical ground reaction forces in hind limbs of dogs during lameness that resulted from impaired tibial nerve function are detectable, as is response during recovery, by use of force platform analysis.     

Systemic atherosclerosis in dogs: histopathological and immunohistochemical studies of atherosclerotic lesions

Cytosolic phospholipase A2 (cPLA2) catalyzes the selective release of arachidonic acid from the sn-2 position of phospholipids and is believed to play a key cellular role in the generation of arachidonic acid. When assaying the human recombinant cPLA2 using membranes isolated from [3H]arachidonate-labeled U937 cells as substrate, 3,3-Dimethyl-6-(3-lauroylureido)-7-oxo-4-thia-1-azabicyclo[3,2,0] heptane-2-carboxylic acid (1) was found to inhibit the enzyme in a dose-dependent manner (IC50 = 72 microM). This beta-lactam did not inhibit other phospholipases, including the human nonpancreatic secreted phospholipase A2. The inhibition of cPLA2 was found not to be time-dependent. This, along with the observation that the degradation of the inhibitor was not catalyzed by the enzyme, demonstrates that the inhibition does not result from the formation of an acyl-enzyme intermediate with the active site serine residue. Moreover, the ring-opened form of 1 is also able to inhibit cPLA2 with near-equal potency. To further characterize the mechanism of inhibition, an assay in which the enzyme is bound to vesicles of 1,2-dimyristoyl-sn-glycero-3-phosphomethanol containing 6-10 mole percent of 1-palmitoyl-2-[1-14C]-arachidonoyl-sn-glycero-3-phosphocholine was employed. With this substrate system, the dose-dependent inhibition was defined by kinetic equations describing competitive inhibition at the lipid/water interface. The apparent dissociation constant for the inhibitor bound to the enzyme at the interface (KI*app) was determined to be 0.5 +/- 0.1 mole% versus an apparent dissociation constant for the arachidonate-containing phospholipid of 0.4 +/- 0.1 mole%. Thus, 1 represents a novel structural class of inhibitors of cPLA2 which partitions into the phospholipid bilayer and competes with the phospholipid substrate for the active site.     

Genuine giant-cell tumour of bone; a combined cytological, histopathological and ultrastructural study

Three patients with a giant-cell tumour of bone were studied clinically, roentgenologically and morphologically, using cytological, histopathological and electron microscopic methods. The tumours were composed of giant cells possessing a great number of mitochondria and stromal cells exhibiting prominent endoplasmic reticulum and Golgi complex. Mitotic activity was only found among the stromal cells. Autophagic vacuoles, lysosomal bodies and degenerative changes of varying severity were found mainly or exclusively among the giant cells, which may indicate that these cells represent an involutionary form of tumour cell. The giant-cell tumours of bone are believed to arise from undifferentiated cells of the bone marrow. Fine-needle aspiration biopsy represents a valuable complement to histopathological examination in the identification of giant cell lesions and diagnosis of genuine cell tumours of bone.