Histologic evaluation and treatment outcome after sequential radiofrequency ablation and hepatic resection for primary and metastatic tumors.

Operative manipulation during hepatic resection (HR) causes tumor cell shedding which is a factor in disease recurrence. Radiofrequency ablation (RFA) causes coagulative necrosis and was used to destroy the tumor before HR. We evaluated tumor necrosis and recurrence of hepatic malignancies treated by sequential RFA/HR. A retrospective review of patients treated with sequential RFA/HR from April 1999 to January 2002 was performed. A Radionics 500-kW RF generator was used to ablate lesions via H2O-cooled electrodes under ultrasound guidance. Segmental HR was performed after RFA. Resected specimens were reviewed with hematoxylin and eosin staining and for apoptosis. Patient follow-up ranged from 10 to 33 months with evaluation of salient clinical, radiologic, and laboratory parameters. Seven patients (four male and three female) ages 62.1 +/- 10.3 years had sequential RFA/HR. Four patients had hepatocellular carcinoma (HCC) and three had colorectal metastases (CRm). The tumors were unifocal right-lobe lesions measuring 4.1 +/- 0.9 cm with a resection margin of 0.4 to 2.5 cm. Extensive necrosis was noted but intact nests of tumor cells occurred in all specimens with minimal apoptosis. Three of seven patients (two HCC and one CRm) developed pulmonary metastases at 3 to 20 months with one HCC patient developing concurrent liver metastases. Two deaths occurred in the HCC group. Sequential RFA/HR may minimize local recurrence; however, the high incidence of pulmonary metastases raises concern of transvenous migration. The histologic findings demonstrate foci of intact tumor cells after RFA. Controlled study of additional patients with long-term follow-up is necessary to better understand these findings.

Fine needle aspiration diagnosis of lipoblastoma of the parotid region. A case report.

BACKGROUND: Lipoblastomas are rare tumors of embryonal fat that occur in infants and children. They are usually located in the extremities and trunk. Two cases in the parotid region have been described. A diagnosis on fine needle aspiration (FNA) specimens has been reported in six cases. CASE: Lipoblastoma of the parotid region occurred in a 6-year-old boy and was diagnosed by FNA. Cytology showed rare lipoblasts and hibernomalike cells in a myxoid background with spindle and stellate mesenchymal cells, mature adipose cells and plexiform capillaries. A 7.0-cm, well-circumscribed mass with lobulated adipose tissue and delicate fibrous bands was resected. Microscopically, it showed a lobulated myxoid stroma, many capillaries, mesenchymal cells, lipoblasts and mature adipose cells. CONCLUSION: Lipoblastoma has to be differentiated from myxoid and lipomatous soft tissue tumors, especially from myxoid liposarcoma, a malignancy that classically affects older individuals and shows pleomorphism, atypical lipoblasts and chromosome-12 translocation. A lipoblastoma diagnosis must be established only after careful consideration of all available clinical, radiologic, cytogenetic and morphologic data.

Study of the regression process in cardiac rhabdomyomas.

Rhabdomyomas are the most common primary cardiac tumors in children, and have been shown to undergo spontaneous regression. The aim of our study was to investigate morphologically and immunohistochemically some mechanisms that may explain this clinical phenomenon. Eleven tumors from three term newborn girls who had physical and radiographic features pathognomonic of tuberous sclerosis were evaluated. Control specimens were left and right heart sections from five autopsies of age- and sex-matched patients who died of causes unrelated to the cardiovascular system. The tumors had been surgically excised from various regions in the heart, and all had similar "typical" histology. Histomorphologic evaluation with von Kossa and alizarin-red stains and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling (TUNEL) method were performed to evaluate cell calcifications, necrosis, and apoptosis. Ubiquitin immunohistochemical study was also conducted to evaluate intracytoplasmic protein degradation. In cardiac rhabdomyomas (CR), all myocytes with acidophilic cytoplasmic myofibrils showed strong intracytoplasmic ubiquitin immunoreactivity, compared with the occasional weak cytoplasmic and focal nuclear positivity in control heart sections. Calcified myocyte nuclei were commonly seen in CR tumoral and nontumoral rhabdomyocytes, whereas control nontumoral cardiac myocytes did not show any calcification. The incidence of TUNEL reactivity seen in CR (4.8 nuclei per 100 cardiac rhabdomyocyte nuclei) was higher than that seen in control heart sections (1.7 nuclei per 106 cardiac myocytes, P < 0.005). The data led us to conclude that the cytoplasmic contents in CR were degraded via the ubiquitin pathway, and from our observation of increased TUNEL positivity, the rate of cell death in CR appeared increased. These findings may explain, to some extent, the mechanism of tumor regression.

Lipochoristomas (lipomatous tumors) of the acoustic nerve.

CONTEXT: Lipochoristomas (lipomatous choristomas) are rare tumors of the acoustic nerve (cranial nerve VIII/vestibulocochlear nerve) within the internal acoustic canal and sometimes the cerebellopontine angle, and are histogenetically believed to be congenital malformations. Their clinically indolent behavior has recently prompted a more conservative management protocol in a quest for maximal nerve/hearing preservation. This approach contrasts sharply with that for the common internal acoustic canal/cerebellopontine angle tumors, the neuroepithelial neoplasms (acoustic schwannomas and meningiomas), which behave more aggressively and have more prominent clinical manifestations. Owing to their rarity, the clinicopathologic features of cranial nerve VIII lipochoristomas have been obtained mainly through case reports. OBJECTIVE: We present the clinicopathologic features of 11 cases of lipochoristomas of cranial nerve VIII. DESIGN: The 11 cases were documented between 1992 and 2003. We performed complete clinical reviews with histologic, histochemical, and immunohistochemical analyses of formalin-fixed, paraffin-embedded tumor samples. RESULTS: The patients were 8 men and 3 women with hearing loss of the right ear (5 patients) or the left ear (6 patients). No patient had bilateral tumors. All lipochoristomas histologically possessed mature adipose tissue admixed with varied amounts of mature fibrous tissue, tortuous thick-walled vessels, smooth muscle bundles, and skeletal muscle fibers, the latter verified with immunohistochemistry. CONCLUSIONS: The histomorphologic and immunophenotypic evidence showed that these tumors are better characterized as choristomas than as simple "lipomas," as they have been labeled in the past. Their overall nonaggressive clinical nature in addition to the characteristic radiologic and histomorphologic findings are important clinicopathologic features for the pathologist to recognize and differentiate, especially during frozen section evaluations, in order to direct the neurosurgeon to a more appropriate conservative therapeutic intervention.

Coexpression and accumulation of ubiquitin +1 and ZZ proteins in livers of children with alpha(1)-antitrypsin deficiency.

The ZZ variant of alpha(1)-antitrypsin deficiency (AATD) is well known to cause liver damage and cirrhosis in some affected children. Ubiquitin abnormality was recently shown to be significant in AATD in childhood cirrhosis. Molecular misreading (MM), defined as faulty transcription of genomic information from DNA into mRNA, as well as its translation into mutant proteins, has been documented in many pathologic processes where aggregation of abnormal proteins occurs. The misread protein, ubiquitin-B(+1) (UBB(+1)), was recently identified in the hallmarks of various neurological disorders. The objective of this study was to determine whether MM of ubiquitin occurs in AATD. Twelve explanted liver specimens from AATD-affected children with cirrhosis were retrieved from archival sources, along with 10 control liver specimens obtained from autopsies of age-matched children with no clinical, gross anatomic, or histologic evidence of liver disease. Double immunofluorescence studies using rabbit polyclonal antibodies against UBB(+1) and AAT were performed on consecutively sectioned tissue. UBB(+1) immunoreactivity was colocalized with AAT in all cirrhotic AATD livers. The control livers were consistently negative. Ubiquitin MM is prominent in AATD-affected cirrhotic livers. This indicates that for children with AATD and cirrhosis, ubiquitin MM is a necessary cofactor to the aggregation of mutant ZZ isoform of AATD.