Clear cell tumor of the lung. A clinicopathologic, immunohistochemical, and ultrastructural study of eight cases

We studied eight clear cell tumors of the lung (CCTL) to better define their clinical, immunohistochemical, and ultrastructural features, and to clarify their distinction from other neoplasms, particularly metastatic renal cell carcinoma. Patients ranged in age from 31 to 67 years (mean, 51 years). Seven patients had clinically benign, asymptomatic lesions measuring less than 2 cm in diameter that were devoid of necrosis. The eighth patient had a symptomatic, partially necrotic CCTL 4.5 cm in diameter that metastasized to the liver and peritoneum; the patient died of tumor 17 years after diagnosis. Ultrastructural study of seven CCTL showed interdigitating cell processes (all cases), primitive cell junctions (five of seven cases), intracytoplasmic glycogen (all cases), and rare dense core granules (two of seven cases). Immunohistochemically, paraffin-embedded sections from all eight CCTL were negative for cytokeratin (CK), epithelial membrane antigen (EMA), chromogranin, and vimentin. Focal staining was seen for S-100 protein (three of eight cases), neuron-specific enolase (three cases), synaptophysin (one case), and Leu 7 (one case). Although these findings suggest that at least some CCTL exhibit neuroendocrine differentiation, the tumor's histogenesis remains uncertain. Of more practical importance, the combined absence of CK, EMA, and vimentin in formalin-fixed, paraffin-embedded CCTL virtually precludes confusion with renal cell carcinoma. Although traditionally considered benign, CCTL larger than 2 cm that are symptomatic, and focally necrotic should be regarded as potentially malignant neoplasms.

Unusual sinonasal small-cell neoplasms following radiotherapy for bilateral retinoblastomas

Two patients developed sinonasal small-cell neoplasms that arose 22 years and 37 years, respectively, following radiotherapy for bilateral retinoblastomas. The tumors were composed of small cells with scant cytoplasm and had a few scattered Homer-Wright rosettes. Immunohistochemically, one tumor was positive for keratin (CAM 5.2 and AE1/AE3), epithelial membrane antigen, and neuron-specific enolase. The other neoplasm was immunoreactive for keratin (CAM 5.2 only) and neuron-specific enolase; it also had focal immunopositivity for S-100 protein, desmin, and muscle-specific actin. Both were negative for CEA, vimentin, melanocyte-specific antigen (HMB45), chromogranin A, synaptophysin, Leu-7, 200 kd neurofilament, and retinal S-antigen. Despite aggressive multimodal therapy, the patients died of metastatic tumor 7 months and 10 months following their initial diagnosis, respectively. Although osteosarcoma is the most frequent second cancer following bilateral retinoblastomas, some patients develop clinically aggressive sinonasal small-cell tumors that are difficult to place into conventional classifications. Both of our cases showed evidence of multidirectional differentiation; one tumor labeled with epithelial and neural markers, and the other expressed epithelial, neural, and myogenous antigens.

Fatal acute pontocerebellar hemorrhage due to an unsuspected spheno-occipital chordoma

Patients with cranial chordomas typically present with a several-month history of progressive cranial nerve palsies. We report the first case (to our knowledge) of a clinically unsuspected sphenooccipital chordoma evolving into an acute pontocerebellar hemorrhage.

Gliomatosis peritonei associated with a ventriculoperitoneal shunt

The authors describe a seven-month-old male patient with non-teratomatous gliomatosis peritonei secondary to the placement of a ventriculoperitoneal shunt. The glial nodules were discovered during microscopic examination of bilateral herniorrhaphy specimens. The glial nature of the implants was confirmed immunohistochemically. The pathogenesis and implications of this finding are discussed, and shunt-related tumor transplantations are briefly reviewed.

Lack of histopathological correlation of malignant ependymomas with postoperative survival

It is widely believed that an important determinant of clinical behavior and prognosis in patients harboring an ependymoma is the histological grade of malignancy of the tumor. Excluding from the present analysis examples of ependymoblastoma (a highly cellular, embryonal tumor occurring in children, with a notably poor prognosis and a tendency to subarachnoid spread), an attempt was made to correlate 15 cases of histologically malignant ependymoma with clinical recurrence and postoperative patient survival times. Ten patients (67%) were alive from 15 months to 14 years after surgery (median survival time 8.8 years); one patient had a histologically benign recurrence 11 years after surgical resection. Five patients (33%) died from a local recurrence of their tumor; their postoperative survival times ranged from 13 months to 6 years (median 2.5 years). The prognosis of malignant ependymomas is therefore highly variable. No correlation was possible between the tumor's histological features, site, or likelihood of recurrence. This lack of clinicohistopathological concordance contrasts with the known correlations that exist in astrocytomas.

Immunohistochemical differences between intracranial germinomas and their gonadal equivalents. An immunoperoxidase study of germ cell tumors with epithelial membrane antigen, cytokeratin, and vimentin

Twenty-six intracranial germ cell tumours (11 germinomas, 10 teratomas, 2 endodermal sinus tumours, 1 teratocarcinoma, and 2 undifferentiated embryonal carcinomas) and 26 gonadal germ cell tumours (13 testicular seminomas, 2 ovarian dysgerminomas, 9 ovarian teratomas, and 2 myometrial choriocarcinomas) were studied by immunoperoxidase with monoclonal antibodies (MAbs) against epithelial membrane antigen (EMA), cytokeratin, and vimentin. Typical tumour cells in three of the 11 germinomas (two of the latter being situated in the posterior fossa) expressed both EMA and cytokeratin, whereas those in the seminomas and dysgerminomas did not. In one seminoma, a few multinucleated giant cells expressed cytokeratin. In three of seven germinomas, vimentin-positive tumour cells were found, but all seminomas and dysgerminomas were negative. In the other forms of intracranial and gonadal germ cell tumours, epithelial and mesenchymal elements displayed the expected patterns of immunoreactivity to the respective determinants. The immunoperoxidase differences between the intracranial germinomas and their gonadal equivalents indicate that, in the former, early epithelial or mesenchymal differentiation of the primordial germ cells may be present. The findings draw attention to the heterogeneous cellular composition of these otherwise morphologically homogeneous-appearing tumours and, especially in the posterior fossa, to their transitional links to the immature teratomas.

Ectopic midline spinal ganglion in diastematomyelia: a study of its connections

The connections of an ectopic midline spinal ganglion associated with an asymptomatic sacral diastematomyelia were studied. The ganglion was intercalated in the ventral root of one hemicord and sent its efferents to the dorsal root of the other hemicord. The afferents joined the anterior root to form a midline intradural spinal nerve in the cauda equina. Islands of ectopic glia were present in both roots and the spinal nerve. Both the midline position of the ganglion and the glial heterotopias can be tentatively explained by the failure of incorporation of the dorsal cell wedge ("Zwischenstrang") into the divided neural tube.

Expression of epithelial membrane antigen in perineurial cells and their derivatives. An immunohistochemical study with multiple markers

Paraffin-embedded surgical pathology specimens from skin (5) and muscle (2) biopsies, from Morton's neuromas (3), traumatic neuromas (8), schwannomas (21), neurofibromas (12), and from one perineurioma and one neurothekeoma were studied by immunoperoxidase histochemistry and antibodies against epithelial membrane antigen (EMA), Leu 7 epitopes (Leu 7), S-100 protein (S-100) and cytokeratins. Normal, reactive and neoplastic perineurial cells stain consistently for EMA, whereas Schwann cells express Leu 7 and/or S-100 positivity. None of the immunoreactive cells stained for cytokeratin. Our findings indicate that perineurial and Schwann cells can easily be distinguished by their different patterns of immunoreactivity with the above markers.

Isoelectric focusing studies on Mycobacterium chelonei

Analytical IEF has been used to give a direct visual comparison of beta-lactamases, down to extremely low levels, from very crude intracellular preparations. Identity and non-identity of strains could be proved by the pattern of bands produced by their beta-lactamases. Mycobacterial species gave a variety of beta-lactamase patterns. Identity was established between some strains of M. chelonei. IEF distinguished between enzymes within both the chelonei and abscessus sub-species that could not be differentiated by other methods. This technique could provide a means of identifying the source of a M. chelonei infection.

Affinities of penicillins and cephalosporins for the penicillin-binding proteins of Escherichia coli K-12 and their antibacterial activity

The affinities of a range of penicillins and cephalosporins for ther penicillin-binding proteins of Escherichia coli K-12 have been studied, and the results were compared with the antibacterial activity of the compounds against E. coli K-12 and an isogenic permeability mutant. Different penicillins and cephalosporins exhibited different affinities for the "essential" penicillin-binding proteins of E. coli K-12, in a manner which directly correlated with their observed effects upon bacterial morphology. Furthermore, the affinities of the compounds for their "primary" lethal penicillin-binding protein targets showed close agreement with their antibacterial activities against the permeability mutant.

Competition of beta-lactam antibiotics for the penicillin-binding proteins of Pseudomonas aeruginosa, Enterobacter cloacae, Klebsiella aerogenes, Proteus rettgeri, and Escherichia coli: comparison with antibacterial activity and effects upon bacterial morphology

The competition of a number of beta-lactam morphogenic probes for the penicillin-binding proteins (PBPs) of Pseudomonas aeruginosa, Enterobacter cloacae, Klebsiella aerogenes, Proteus rettgeri, and Escherichia coli has been studied. The results indicate that the various gram-negative bacteria have similar, but not identical, PBP patterns and that the individual proteins probably perform similar morphogenic functions as in E. coli K-12. Comparison of the 50% binding concentrations of the compounds for the various PBPs of the five strains with their antibacterial activity indicates that the different antibiotics are excluded to a greater or lesser degree by the outer membrane permeability barrier and that the exclusion is most pronounced in P. aeruginosa.

Inhibition of peptidoglycan cross-linking in growing cells of Escherichia coli by penicillins and cephalosporins, and its prevention by R factor-mediated beta-lactamase

The degree of peptidoglycan cross-linking has been studied in growing cells of a Dap(-) Lys(-) auxotroph of Escherichia coli K-12 by following the incorporation of [(3)H]diaminopimelic acid into the lysozyme digestion products of crude, isolated peptidoglycan. The percentage of inhibition of cross-linking increases with increasing concentrations of penicillin G, cephaloridine, and cefuroxime. When the R factor R1drd 19 was introduced into the strain by conjugation, it was found that the type IIIa, beta-lactamase specified by the plasmid was able to protect the cross-linking target against inhibition by penicillin G but not against cephaloridine, even though the beta-lactamase hydrolyzes this substrate 50% faster than penicillin G. Cefuroxime, which is completely resistant to hydrolysis by the type IIIa beta-lactamase, inhibited the peptidoglycan cross-linking target in both the R(+) and R(-) variants of the assay strain. A mutant plasmid, R1drd19amp2, which specified no type IIIa beta-lactamase synthesis, could not provide protection of the cross-linking target against penicillin G. The significance of these results, in relation to the ability of the antibiotics to pass the permeability barrier of the bacterial envelope, is discussed.

The use of analytical isoelectric focusing for detection and identification of beta-lactamases

BETA-Lactamases (EC. 3.5.2.6) from strains of Gram-negative bacteria have been studied using analytical isoelectric focusing. This permits a visual comparison of the patterns of beta-lactamase bands produced by enzymes from different organisms. Purification of crude intracellular preparations is unnecessary and the technique is sufficiently sensitive to demonstrate beta-lactamase in mutants previously reported to lack the enzyme. R that have not been distinguished from one another biochemically or immunologically can be differentiated by isoelectric focusing. Conversely, the enzymes specified by the R factors RTEM, R1 and RGN14, with identical isoelectric focusing patterns have the same biochemical properties. Chromosomal and R-factor-mediated beta-lactamases from single strains have been separated and their identities confirmed by immunoisoelectric focusing. R factor-mediated enzymes gave identical isoelectric focusing patterns irrespective of the host strain. Isoelectric focusing can therefore be used to observe the transfer of beta-lactamases carried by R factors.