An Adult Atypical Fibromyxoid Tumor of the Urinary Bladder

A case of atypical fibromyxoid tumor of the urinary bladder in a 32-year-old woman is reported. The patient had never complained of urinary symptoms, and bladder tumefaction was revealed fortuitously at pelvic ultrasound. Cystoscopy revealed a peanut-sized mass. Microscopically, the lesion was composed of strap- and tadpole-shaped cells resembling rhabdo-myoblasts. For this reason, the tumor was initially diagnosed as embryonal rhabdomyosarcoma. However, immunohistochemical study was negative for muscle origin, and the tumor has subsequently proved benign. The reported case illustrates the value of immunohistochemical study in the evaluation of the true type of bizarre stroma cells in this pseudo-sarco-matous lesion. Their recognition is important, because the therapeutic consequences of misinterpreting this tumor as a sarcoma are great.

Ossifying fibromyxoid tumor of soft parts. A clinicopathological analysis of 59 cases

We describe 59 cases of a microscopically unique neoplasm that has not been previously reported. The tumor almost exclusively affected adults (range 14-79 years) and had a male predominance (38 men and 21 women). It presented in most cases as a small, painless, well-circumscribed mass (median, 4 cm) in subcutis or muscle. It occurred chiefly in the upper and lower extremities (40 cases) and less frequently in the trunk (11 cases) and the head and neck region (eight cases). Microscopically, the tumor was partly lobulated and composed of small, round cells that had vesicular nuclei and indistinct cytoplasm. Typically, the cells were arranged in a cord- or nestlike pattern within a myxoid matrix that frequently showed transitions toward hyaline fibrosis and focal osteoid formation. In about two-thirds of the cases, the cells contained immunoreactive S-100 protein. An additional typical feature, seen in 48 (81%) of the 59 cases, was the presence of an incomplete shell of mature bone in the capsular region of the tumor. Follow-up information, available in 41 cases, revealed that 11 patients (27%) experienced one or more recurrences. One patient with three recurrences developed a second tumor in the opposite thigh, presumably a metastasis. None of the patients died of the tumor, but three died of causes unrelated to the disease. Although the histogenesis is uncertain, cartilaginous or neural origin seem to be most likely. Until this issue is resolved, we prefer the descriptive and less committal designation of "ossifying fibromyxoid tumor of soft parts."

[Desmoid fibromatosis in absorption infrared spectroscopy, emission spectral analysis and roentgen diffraction recording]

The authors present results of serial quality and quantity microanalyses of bone patterns and dental tissue patterns in patient with desmoid fibromatosis. Methods of absorption spectroscopy, emission spectral analysis and X-ray diffraction analysis with follow-up to x-ray examination are tested. The above mentioned methods function in a on-line system by means of specially adjusted monitor unit which is controlled centrally by the computer processor system. The whole process of measurement is fully automated and the data obtained are recorded processed in the unit data structure classified into index sequence blocks of data. Serial microanalyses offer exact data for the study of structural changes of dental and bone tissues which manifest themselves in order of crystal grid shifts. They prove the fact that microanalyses give new possibilities in detection and interpretation of chemical and structural changes of apatite cell.

Pleomorphic fibroma of the skin: a benign neoplasm with cytologic atypia. A clinicopathologic study of eight cases

A clinicopathologic study of eight examples of polypoid and dome-shaped cutaneous fibrous lesions with sparse cellularity but striking nuclear atypia and rare mitotic figures is presented. Positive immunohistochemical staining for vimentin and actin supported the fibroblastic nature of these lesions. All eight cases were adults whose ages ranged from 33 to 67 years (mean 52 years). Five were women and three were men. Five lesions were located on extremities, two on the trunk, and one on the face and they measured from 4 to 16 mm in greatest dimension. The lesions were clinically followed from 4 months to 5 years. They all showed benign clinical behavior, with only one local recurrence in a lesion that had been incompletely removed. The nuclear atypia seen in these fibrous lesions may be similar to that which occurs in other benign mesenchymal neoplasms, such as pleomorphic lipoma, pleomorphic leiomyoma, ancient schwannoma, and variants of dermatofibroma with atypical cells. We suggest that "pleomorphic fibroma" is an appropriate term for this lesion based on its histologic differentiation, cytologic atypia, and benign clinical course.

Myofibroblasts from diverse pathologic settings are heterogeneous in their content of actin isoforms and intermediate filament proteins

We examined by immunofluorescence the distribution of vimentin, desmin, alpha-smooth muscle actin and alpha-sarcomeric actin in normal human soft tissues and in pathologic tissues containing myofibroblasts, including normally healing granulation tissue, hypertrophic scar, and fibromatosis. The pattern of actin isoforms was also documented biochemically by two-dimensional gel electrophoresis. Fibroblastic and/or myofibroblastic cells in each setting always expressed vimentin and never alpha-sarcomeric actin. Moreover, these cells showed an heterogeneous cytoskeletal composition which defined four phenotypes: (a) cells expressing only vimentin; (b) cells expressing vimentin, alpha-smooth muscle actin and desmin; (c) cells expressing vimentin and alpha-smooth muscle actin; and (d) cells expressing vimentin and desmin. Given this, two groups of lesions are distinguished: the first contains only vimentin cells and consists of normally healing granulation tissue, eschars and normally healed scars; the second contains vimentin cells admixed with variable proportions of vimentin, alpha-smooth muscle actin and desmin, vimentin and alpha-smooth muscle actin, and vimentin and desmin cells and consists of hypertrophic scars and fibromatoses. Immunogold electron microscopy showed that alpha-smooth muscle actin was present in a proportion of cells with ultrastructural features of myofibroblasts. Our findings suggest that contrary to myofibroblasts of normally healing granulation tissue and normally healed scars, myofibroblasts of pathologic conditions characterized by chronic retraction express always immunochemical features indicative of smooth muscle differentiation.

Immunostaining in atypical fibroxanthoma of the skin

We have studied 12 cases of cutaneous atypical fibroxanthoma using immunohistochemistry to demonstrate lysozyme, alpha-1-antitrypsin, S-100-protein, receptors for peanut agglutinin, and intermediate filaments. Results were compared with immunostaining in 24 cases of other so-called fibrohistiocytic tumours. In addition 2 cases of atypical fibroxanthoma and 6 cases of fibrohistiocytic tumours were stained by monoclonal antibodies specific for the monocyte cell lineage (Ki-M1, Ki-M2, Ki-M6, Ki-M7, Ki-M8, OKM-1 and Leu-M1) and double-stained by monocyte-markers and Ki-67. The immunophenotype of atypical fibroxanthoma was rather similar to the marker profile found in malignant fibrous histiocytoma. All atypical fibroxanthomas were positive for vimentin and negative for epithelial markers. Monocyte lineage-specific determinants could be demonstrated in varying amounts in cells suggestive of being reactive. In contrast proliferating--Ki-67 positive--cells did not express monocyte/macrophage related antigens in atypical fibroxanthoma and malignant fibrous histiocytoma both. As to the histogenesis of these tumours our findings speak in favour of a derivation from primitive mesenchymal cells rather than from histiocytes.

Production and characterization of monoclonal antibody to dermatan sulfate proteoglycan

We purified dermatan sulfate proteoglycan (PG) from the capsule of human ovarian fibroma for use as an immunogen. A monoclonal antibody, designated 6B6, was produced which reacts to the intact molecule of dermatan sulfate PG and the chondroitinase AC-treated core molecule on Western-blotted nitrocellulose membrane. Localization of materials showing crossreactivity to this antibody was studied in human tissues by indirect immunohistochemistry. The interstitial elements of almost all tissues examined were positive for the antibody: dermis, submucosal layer of digestive tract, perichondral layer, perivascular connective tissue, perineurium, adventitia of aorta, vessel wall of vein, pleura, and fibrous capsule of kidney and liver. Positive staining was also observed in fibrous elements at post-necrotic foci of cardiac muscle and pancreas, and at atherosclerotic lesions of aorta. The distribution of the antigen, core protein of the dermatan sulfate PG, revealed with 6B6 was compared to that of the dermatan sulfate side chain, which was demonstrated with antibody 9A-2 (Couchman et al.: Nature 307:650, 1984) after treatment with chondroitin sulfate B-lyase. The distribution of both antigens, core protein, and dermatan sulfate side chains showed the same pattern, with minor exceptions. The antibody 6B6 will be a useful tool to study the immunohistochemical localization of dermatan sulfate PG.

Spindle-cell and pleomorphic neoplasms of the skin. A clinicopathologic and immunohistochemical study of 30 cases, with emphasis on "atypical fibroxanthomas"

Atypical fibroxanthoma belongs to the family of spindle-cell and pleomorphic neoplasms of the skin. The lineage of differentiation of this tumor and the means whereby it can be diagnostically separated from other similar morphologic entities have been controversial. In order to address these issues, the authors studied 30 spindle-cell and/or pleomorphic cutaneous tumors, including atypical fibroxanthomas (AFXs), superficial malignant fibrous histiocytomas (MFHs), dermatofibrosarcoma protuberans (DFSPs), sarcomatoid squamous-cell carcinomas (SCCs), spindle-cell malignant melanomas (MMs), and leiomyosarcomas, (LMSs). These cases were analyzed using a panel of eight antibodies and the immunoperoxidase technique. AFXs were reactive for vimentin, alpha-1-antichymotrypsin (AACT), alpha-1-antitrypsin (AAT), and cathepsin-B (CB) but failed to display cytokeratin (CK), epithelial membrane antigen (EMA), S-100 protein, and desmin. MFHs and DFSPs exhibited immunophenotypic profiles that were nearly identical to that just described. In contrast, SCCs were typified by positivity for CK and EMA; MMs exhibited uniform reactivity for S-100 protein; and LMSs contained desmin in four of five cases. A surprising result was the expression of S-100 by LMSs. Also, all tumors displayed at least one of the three proteolytic enzymes assessed in this study (AAT, AACT, and CB), demonstrating the relative diagnostic nonspecificity of these determinants. It is concluded that AFXs are "fibrohistiocytic" neoplasms, with substantial morphologic and immunohistochemical similarity to MFHs. The immunohistochemical classification of spindle-cell and pleomorphic tumors of the skin necessitates the use of antibody panels to assess the presence of markers that are characteristic of each diagnostic group.

Flow cytometric DNA analysis of malignant fibrous histiocytoma and related fibrohistiocytic tumors

Fibrohistiocytic neoplasms with similar histologic characteristics may have vastly different biologic behaviors. We studied 23 fibrohistiocytic tumors to determine if cellular DNA content was correlated with clinical outcome. Archival paraffin blocks of 9 malignant fibrous histiocytomas (MFH), 3 dermatofibrosarcoma protuberans, 9 dermatofibromas, 1 juvenile xanthogranuloma, and 1 nodular fasciitis were processed, stained with propidium iodide, and analyzed by flow cytometry. Five of 9 (56%) MFH and 1 of 3 (33%) dermatofibrosarcoma protuberans were aneuploid. All 11 benign fibrohistiocytic tumors were diploid. Local recurrence occurred in 3 of 5 (60%) cases of aneuploid MFH, but in none with a diploid MFH tumor. No cases of dermatofibrosarcoma protuberans or benign tumors recurred. Aneuploidy was associated with decreased survival, as 2 of 5 patients with aneuploid MFH died within 1 year of diagnosis whereas all 4 patients with diploid MFH tumors are alive after an average follow-up of 4 years (range, 1 to 11). The diploid and aneuploid groups did not differ in clinical stage at the time of diagnosis. Our results indicate that retrospective DNA analysis can detect aneuploidy in both MFH as well as other fibrohistiocytic tumors, and that aneuploidy in MFH may place the patient at increased risk for local recurrence and mortality.

Diagnostic immunohistochemistry of canine round cell tumors

Sixty-five canine skin neoplasms studied using immunocytochemistry, included 22 histiocytomas, 18 amelanotic melanomas, 14 cutaneous lymphosarcomas, six mast cell tumors, and five transmissible venereal tumors. Formalin-fixed, paraffin-embedded sections were stained using the avidin-biotin-peroxidase complex (ABC) immunoperoxidase technique for reactivity with S-100 protein, kappa and lambda immunoglobulin light chains, alpha-1-antitrypsin, alpha-1-antichymotrypsin, leukocyte common antigen (LCA), neuron-specific enolase, keratin, cytokeratin, muramidase, and vimentin. Detection of S-100, kappa and lambda light chains, neuron-specific enolase, and vimentin were most useful for screening these neoplasms. None of the markers examined was consistent in staining histiocytomas. While reactivity of S-100 (ten cases) and neuron-specific enolase (ten cases) was detected in some amelanotic melanomas, lambda light chain immunoglobulin (eight cases) was relatively consistent in cutaneous lymphomas. Mast cell neoplasms reacted with avidin and, therefore, were positive, even on negative control sections. Vimentin reacted strongly on all amelanotic melanomas and transmissible venereal tumors examined. These antibodies are helpful adjuncts in the differential diagnosis of canine skin tumors.

Estradiol and progesterone receptors in a case of fibromatosis of the breast

A case of fibromatosis of the breast with positive cytosol assays for estradiol and progesterone receptors is described. Estrogen and progesterone receptors in fibromatosis have been only rarely reported in the English literature, and never, to our knowledge, in fibromatosis of the breast. We discuss the implications of these findings and review the literature.

Spindle cell squamous carcinoma of the lung. Immunocytochemical and ultrastructural study of a case

A case of squamous cell carcinoma of the lung showing extensive spindle transformation is presented. On light microscopy, the tumour showed sheets and fascicles of elongated fusiform cells resulting in a growth pattern which closely resembled a sarcoma. Immunocytochemistry using tissue-specific antibodies against intermediate filaments demonstrated exclusive labelling of the tumour cells with prekeratin antibodies. Electron microscopy showed well-formed intercellular junctions and thick bundles of tonofilaments within the cytoplasm of the cells further confirming the squamous epithelial nature of the neoplasm. The findings in the present case point to the existence of a non-metaplastic spindle cell variant of squamous carcinoma of the lung. The possible mechanisms which may account for the spindle shape of the cells are reviewed.

Intermediate filaments cytokeratin and vimentin in ovarian sex cord-stromal tumours with correlative studies in adult and fetal ovaries

The expression of the intermediate filaments cytokeratin and vimentin were studied immunohistochemically in a series of ovarian sex cord-stromal tumours (26 adult and juvenile granulosa cell tumours, 11 thecomas, six fibromas, three Sertoli-Leydig cell tumours and 1 sex cord tumour with annular tubules). Contrary to previous reports, granulosa cell tumours expressed cytokeratins as well as vimentin. Thecomas and fibromas expressed vimentin only. In Sertoli-Leydig cell tumours and the sex cord tumour with annular tubules, both cytokeratins and vimentin were detected. Correlative studies in adult ovaries showed that patterns of expression in non-neoplastic granulosa, thecal and stromal cells correspond to their neoplastic counterparts. Investigation of fetal ovaries demonstrated that these patterns of intermediate filament expression exist from relatively early stages of development. Ovarian surface epithelium and rete ovarii, like granulosa cells, co-expressed cytokeratin and vimentin. The demonstration of cytokeratins in granulosa cells and the reported presence of desmosomes and tonofilaments, suggests the epithelial nature of these cells although not clarifying their histogenesis. The presence of both these intermediate filaments in granulosa and Sertoli-Leydig cell tumours as well as in some ovarian carcinomas which may mimic them, limits their value in differential diagnosis between these tumour groups.

Metastatic atypical fibroxanthoma of skin

Metastases from an atypical fibroxanthoma of skin have been reported but are very few in the literature. We had a personal case which, originally localized on the nostril, gave metastases to the cervical regional lymph node with no local recurrence. We examined both the primary and metastatic tumor by conventional histological stains and by immunoperoxidase technique to localize lysozyme, alpha-1-antitrypsin, ferritin and factor VIII antigens. The results show a clear correspondence between the primary and metastatic tumor.

Immunoprofile of benign and malignant fibrohistiocytic tumors

Formalin-fixed, paraffin-embedded tissue sections from 26 malignant fibrous histiocytomas (MFH) and 61 benign fibrohistiocytic proliferations (BFHP) were evaluated immunohistochemically. An avidinbiotin-peroxidase technique was used to determine immunoreactivity for alpha-1 antichymotrypsin, muramidase, HLA-DR, leucocyte common antigen, S-100 protein, vimentin, desmin, and keratin. MFHs were consistently positive for ACT and vimentin and inconsistently reactive for the other antigens. MFHs were negative for LCA suggesting a mesenchymal origin for these lesions. In the MFH histologic subtypes, antigen expression was not significantly different to be useful in their classification. Also no distinctive pattern emerged relative to immunoreactivity and tumor location. The benign lesions, giant cell tumor of tendon sheath, dermatofibroma, and oral benign fibrous histiocytoma differed from the MFHs in that they were often LCA positive, suggesting origin from hematopoetic mononuclear-macrophages. The immunoprofiles of peripheral fibromas and "giant cell" fibromas were felt to be consistent with origin from mesenchymal cells. Several of the antigens studied could be used to differentiate the benign lesions studied from other benign neoplasms. The antigens were, however, of little value in separation of benign and malignant lesions.

Histogenesis of unique elastinophilic fibers of elastofibroma: ultrastructural and immunohistochemical studies

Electron microscopy and both light and electron microscopic immunohistochemical tests for elastin were employed to study the morphogenesis of the unique elastinophilic fibers of an elastofibroma removed from the subscapular region of a 62-year-old woman. Ultrastructurally, as shown by tannic acid stain, elastinophilic fibers of the elastofibroma consisted of central cores and outer zones. The latter were composed of various sizes of vaguely demarcated, irregularly shaped amorphous components and compactly and randomly arranged large amounts of microfibrils. The electron microscopic immunohistochemical results showed that the small-sized amorphous components and microfibrils in the outer zones of the elastinophilic fibers were stained evenly and of granular texture, but the vaguely outlined large amorphous components were not stained. These findings were interpreted as indicating that the amorphous components of the outer zones of elastinophilic fibers were less compact and allowed the penetration of antielastin antibody. The unique elastinophilic fibers of elastofibromas appear not to be formed by the degeneration of the fibers but by abnormal elastogenesis, including an abnormal arrangement of microfibrils.

[A biochemical study on neurofilament proteins in soft tissue tumors]

Since the diagnosis of soft tissue tumors is often difficult, neurofilament proteins were analyzed to contribute to the diagnosis for neurogenic tumors. Neurofilaments are composed of three polypeptides which generally are in the range of 200,000, 160,000 and 68,000 daltons; these are components of the axonal flow. Materials of the neurogenic tumors were neurinoma, neurofibroma and malignant schwannoma. Control materials were human sciatic nerve, human blood, desmoid tumor, leiomyoma and lipoma. For biochemical analysis, 10% sodium dodecyl sulfate polyacrylamide gel electrophoresis (PAGE) and two dimensional electrophoresis (sodium dodecyl sulfate PAGE and isoelectric focusing) were used. For the morphological study, H.E. stain, Bodian stain, luxol fast blue stain and electron microscope were employed. In this study, observation of bands of neurofilaments in the neurogenic tumors, the concentrated band of collagen in desmoid tumor and the band of actin in leiomyoma were possible. This method of analysis thus can be used as supplements for differential diagnosis of soft tissue tumors.

Distinctive immunohistochemical labeling of epithelial and mesenchymal elements in laryngeal pseudosarcoma

A laryngeal squamous cell carcinoma in situ with an underlying spindle cell nodule (pseudosarcoma) was immunohistochemically labeled with antibodies to tissue-specific intermediate filament proteins, including desmin, vimentin, and cytokeratin. Two distinct populations of cells were found within the lesion: cytokeratin-positive cells, corresponding to the carcinomatous component of the tumor, and vimentin-positive spindle cells in the subepithelial nodule. In view of the strict specificity of antivimentin and anticytokeratin for cells of mesenchymal and epithelial origin, respectively, it is proposed that the two components of the pseudosarcoma in our case are not morphologic variants of the same tumor, and that the subepithelial nodule represents a mesenchymal lesion. These results can, however, not be extrapolated to other cases since in some the spindle cell component may represent metaplastic epithelial cells. In view of the difficulties encountered in reaching a correct diagnosis in these lesions, it is recommended to use intermediate filament typing to elucidate the nature of the spindle cells in this controversial tumor.

Elastase digestion and biochemical analysis of the elastin from an elastofibroma

Elastin from both elastofibroma and control skin samples was analyzed by means of pancreatic elastase digestion and subsequent biochemical studies, such as for elastin content and amino acid composition. Elastin of elastofibroma was more resistant to elastase digestion than that of controls. Elastin content was increased almost twice (wet weight) or three times (dry weight) in elastofibroma. The amino acid composition had the characteristics of elastin; however, the cross-linking amino acids such as desmosine, isodesmosine, and lysinonorleucine were increased in elastofibroma when compared with controls. An electron microscopic study showed that the interspersed cells had prominent intermediate filaments without any periodicity, pinocytotic vesicles, rough endoplasmic reticulum, and other organelles. These cells were considered to be fibroblasts not myofibroblasts. Therefore, it could be supposed that fibroblasts newly form an elastin that has a slightly different amino acid composition from that of controls.

Giant cell fibroblastoma: an immunohistochemical study

Giant cell fibroblastoma is a rare, benign soft tissue tumor occurring in childhood. A 34-year-old woman presented with a giant cell fibroblastoma involving the chest wall. Histologic features include an infiltrating spindle-cell tumor involving the dermis and subcutaneous fat containing characteristic sinusoidal spaces rimmed by spindle cells and multinucleate giant cells. Immunohistochemical studies support a fibrohistiocytic differentiation.

DNA flow cytometry of ovarian tumors with correlation to histopathology

Tissue samples from 49 women with seven benign and 42 malignant ovarian tumors were examined by means of DNA flow cytometry (FCM). The FCM data (DNA-ploidy and the number of S-phase fractions) were compared with the International Federation of Gynecology and Obstetrics (FIGO) stage, the histologic grade of differentiation and in some cases with the clinical outcome. The benign ovarian tumors were all diploid with a mean of 2.1% (+/- 1.66) S-phase fractions. Adenocarcinomas with the histologic grade 1 were diploid and had a mean of 2.1% (+/- 1.17) S-phase fractions. Grade 2 adenocarcinomas were aneuploid in eight of nine cases and revealed an increased proliferative activity (7.7% +/- 2.67 S-phase fractions). A high number of aneuploid cases (nine of 13) and an increased DNA synthesis were found in grade 3 adenocarcinomas (12.0% +/- 5.72 S-phase fractions). Four of six malignant nonepithelial tumors also had high numbers of S-phase fractions (9.7-14.5%). A significant correlation between the histologic grade and the DNA synthesis, FIGO stage, and DNA-ploidy was found. DNA-FCM may be used as an additional diagnostic tool supplementing routine histopathologic examination of ovarian tumors for better biological characterization, especially for those with uncertain grading, for grade 2 neoplasms, and for malignant nonepithelial tumors.

Staining patterns of human pre-malignant oral epithelium and squamous cell carcinomas by monoclonal anti-keratin antibodies

Formalin-fixed, paraffin-embedded biopsies of metaplastic keratinized oral mucosa (fibromas and leukoplakias), oral mucosa with epithelial dysplasia and oral squamous cell carcinomas were stained with two monoclonal anti-keratin antibodies (AE1 and AE2). Intense suprabasal staining was seen with AE1 in metaplastic keratinized epithelium, whereas staining of adjacent normal unkeratinized epithelium generally was restricted to basal cells. In dysplastic epithelium and squamous cell carcinomas, staining with AE1 revealed a highly disturbed anti-keratin staining pattern. AE2 stained metaplastic keratinized epithelium in a suprabasal pattern but adjacent unkeratinized epithelium did not stain. In dysplastic epithelium and squamous cell carcinomas, AE2 staining was variable and sometimes absent. Further studies are indicated to clarify whether changes in anti-keratin staining patterns can be used for diagnostic and prognostic purposes.

Atypical fibroxanthoma. A study with antibody to S-100 protein

Fourteen biopsy specimens from ten patients with atypical fibroxanthoma were studied with the peroxidase-antiperoxidase method for binding of S-100 antibody. Six specimens from four patients were minimally positive. The S-100-positive cells were observed in greatest concentrations at the periphery of the lesions and were associated with perivascular inflammatory cells. By this method, it appears that there is not a Langerhans' cell type of atypical fibroxanthoma. The S-100 antibody can help differentiate desmoplastic juvenile melanoma and malignant melanoma from atypical fibroxanthoma.

The cutaneous pathology of Cowden's disease: new findings

Histological, histochemical and immunohistochemical findings were studied in 40 cutaneous biopsies from 7 patients with Cowden's disease. Most facial biopsies showed a spectrum of trichilemmomas and related follicular malformations, including cylindrical trichilemmomas, lobulate trichilemmomas (14 lesions), and a keratinizing type sharing features with inverted follicular keratosis. One facial growth showed trichilemmomal changes without apparent follicular origin. Studies for common papilloma virus structural antigens were negative, apart from a typical common wart in one patient. Immunohistochemical studies in 6 facial trichilemmomas and acral keratoses, using a panel of anti-keratin antibodies, disclosed only abnormal differentiation with lack of large keratins in the lobulate trichilemmomas. Nine biopsies revealed a distinctive type of fibroma characterized by an organized pattern of interwoven fascicles of collagen bundles with a laminated or tortuous appearance, embedded in abundant mucin. A number of fibromas showed striking hyalinization; these may represent a second microscopic hallmark of Cowden's disease in addition to facial trichilemmomas.

The pattern of distribution of laminin in neurogenic tumors, granular cell tumors, and nevi of the oral mucosa

Oral tumors of presumably neuroectodermal origin were stained with anti-laminin antibody by a double layered immunofluorescence technique. A marked positive staining for laminin was found in neurofibromas and neurilemmomas although the pattern of laminin distribution was slightly different. Accentuated staining was seen in Verocay bodies. In granular cell myoblastomas (GCM), small groups of tumor cells were encircled by laminin-positive material, whereas individual tumor cells were unstained. In nevi, diffusely spread nevus cells were surrounded by a rim of laminin, whereas when arranged in nests whole groups of cells were encircled by laminin as seen in the GCM. Ordinary oral fibromas included as controls were negative except for the expected positive staining of basement membranes normally occurring in the tissues. Immunohistochemical demonstration of laminin seems to be a valuable aid in differential diagnosis of soft tissue tumors and may provide useful information about the pathogenesis of various lesions.

Spindle cell tumours of the skin of debatable origin. An immunocytochemical study

Twelve cases of malignant spindle-cell and sarcomatoid tumours of the skin of debatable nature were studied by immunocytochemical methods, using four antisera which might help contribute to resolution of the problems. The initial diagnosis made on structural grounds was confirmed by immunocytochemistry in six of eight cases in which a specific diagnosis had been made (one melanoma, three squamous carcinomas and two atypical fibroxanthomas). One case, initially regarded as AFX was reclassified as a squamous carcinoma, while a further case of possible AFX could not be confirmed by immunocytochemical study. Of the four cases in which structural examination was inconclusive, two were identified as squamous carcinomas and one as a melanoma by virtue of tumour markers. The fourth case was an intriguing actin-rich tumour of uncertain nature. Immunocytochemistry, despite certain limitations, has a valuable role to play in the analysis of the problematic spindle-cell malignant and pseudomalignant tumours of the skin.

Nuclear and nucleolar localization of the 72,000-dalton heat shock protein in heat-shocked mammalian cells

The intracellular location of the major induced mammalian heat shock (or stress) protein (Mr = 72,000) has been determined by both biochemical and immunological methods. This protein, shown here to be comprised of at least three structurally related isoforms, is produced at high levels within 30 min to 1 h following heat treatment of cells. Biochemical fractionation of cells grown under heat shock showed that following its synthesis a portion of the 72,000-Da protein (and its isoforms) becomes associated with the nucleus while some remains in the cytoplasm. Indirect immunofluorescence studies using antiserum directed against the major isoforms of the 72,000-Da protein were carried out in normal and heat-shocked cells as well as in cells grown under stress by exposure to either an amino acid analogue or to sodium arsenite. Diffuse cytoplasmic and nuclear staining was observed in cells grown at 37 degrees C. In cells grown under heat shock conditions, both the cytoplasmic staining and the nuclear staining were found to increase with the nuclear staining consisting of both granular and patch-like structures, the latter being coincident with phase-dense nucleoli. In the case of cells exposed to amino acid analogues or to sodium arsenite, only cytoplasmic and to a lesser extent nuclear staining was observed, i.e. no localized nucleolar fluorescence was observed. Following return of heat shock-treated cells to normal growth temperatures, both the synthesis of the 72,000-Dalton stress protein and its nucleolar staining were found to diminish.

[Immunodiffusion of non-histone chromosomal proteins from human skin tumors]

A previously unpublished reaction of precipitation in agarose between histone and non-histone proteins extracted in saline buffer from nuclei of human skin tumors, is reported. Two bands of precipitation similar to those in an immunodiffusion reaction between NHP and specific antisera, were observed. The reaction described is very similar to the affinodiffusion reaction of glycoproteins and lectins in agarose.

Immunohistochemical investigations of tumors of supposed fibroblastic-histiocytic origin

The aim of this study was to localize alpha 1-antitrypsin, ferritin, and lysozyme by means of the indirect immunoperoxidase technique and to evaluate the significance of these antigens as markers of histiocytic differentiation in tumors of a supposed dual fibroblastic-histiocytic origin. The series comprised 31 malignant fibrous histiocytomas (MFH) of the pleomorphic, spindle cell, and myxoid types, four cutaneous fibrous histiocytomas, and four atypical fibroxanthomas, four dermatofibrosarcoma protuberans, and two osteoclastomas of bone. For comparison, 15 soft tissue sarcomas of various other types were examined. Of the MFHs of the pleomorphic type, 18 of 22 (82 per cent) were positively stained for alpha 1-antitrypsin and 12 of 22 (54 per cent) were positively stained for ferritin. Of the five MFHs of the spindle cell type, none was positively stained for alpha 1-antitrypsin, three were positive for ferritin, and one was positive for lysozyme. None of the myxoid variants (corresponding to grade I-II myxofibrosarcoma) was positively stained for either of the antigens. These results and the observations made on the cutaneous fibrous histiocytomas, atypical fibroxanthomas, dermatofibrosarcoma protuberans, and the various soft tissue sarcomas indicated that 1) alpha 1-antitrypsin is a valuable marker of histiocytic differentiation in both benign and malignant fibrous histiocytomas, 2) ferritin can be visualized in more than half of these fibroblastic-histiocytic tumors, and the presence of ferritin distinguishes the spindle cells of these tumors from fibroblasts of connective tissue and most fibrosarcomas, and 3) lysozyme, although a good marker of histiocytic differentiation in ordinary histiocytes and benign fibrous histiocytomas, is a poor marker of neoplastic histiocytes of malignant tumors. The results further support the concept that MFH is a tumor of a dual fibroblastic-histiocytic origin.

Membrane proteins in human skin tumors

The microsomal, mitochondrial, and nuclear fractions of cutaneous tumors have been investigated. Cutaneous tumors were homogenized and microsomal, mitochondrial, and nuclear fractions were purified. The membrane proteins were solubilized with sodium duodecyl sulfate (SDS). The membrane lipids were removed and membrane proteins were solubilized again in a small volume of SDS solution and chromatographed in SDS-acrylamide slab-gel. The plates were stained with Coomassie Brilliant Blue to show protein bands. The preliminary results show that the electrophoretic profiles of microsomal proteins are characteristic of some tumors.

Ultrastructural histochemistry of infantile digital fibromatosis

A case of infantile digital fibromatosis was studied by light and electron microscopy histochemistry. Using two different acidic solutions of phosphotungstic acid at varying pHs, the round inclusions characteristic of this tumor were shown to have a high protein content with little or no carbohydrates. The histochemical reactivity of the inclusions was similar to that of the cytoplasmic microfibrils in the tumors cells and consistent with the idea that both the inclusions and the microfibrils represent actin. There is, however, no definite proof that the tumor cells are myofibroblasts. At the present time, this tumor should be viewed as a peculiar expression of deranged assembly or metabolism of filamentous proteins or both.

Morphological and histochemical studies on the collagen in neurinomas, neurofibromas, and fibromas

The collagen in neurinomas, neurofibromas was studied by optical and electron microscopy. Neurinomas were shown to be composed mainly of thin argyrophilic, weakly birefringent fibers formed by thin collagen fibrils. Fibromas presented only thick, non-argyrophilic, strongly birefringent fibers composed of thick collagen fibrils. Neurofibromas showed populations of the two above-mentioned types of fibers occupying different areas of their parenchyma. These results suggest that the collagen of neurinomas is mainly of type III, while fibromas present collagen type I, and neurofibromas are composed of both types of collagen.

Elastofibroma dorsi: an immunochemical study of collagen content

The types of collagen present in a case of elastofibroma dorsi were determined using type specific, characterized collagen antibodies. The presence of type II collagen (normally present only in articular cartilage and in selected ocular structures) is discussed with regard to the pathogenesis of this lesion, and the use of collagen antibodies is discussed with regard to their potential value in better characterizing and classifying mesenchymal tumors.

Quantitation of bovine papilloma viral DNA in viral-induced tumors

Bovine papilloma virus (BPV) DNA was labeled in vitro under conditions of repair synthesis and subsequently used as a "probe" in DNA-DNA reassociation studies to detect BPV-specific DNA sequences in a viral-induced calf meningioma and hamster fibroma. In vitro labeled BPV DNA had denaturation characteristics expected for duplex DNA and denatured DNA reassociated with apparent second-order kinetics. Analysis of in vitro labeled BPV DNA reassociation rates in the presence of excess tumor DNA revealed that the calf meningioma contained approximately 700 to 800 BPV genome equivalents per diploid cell whereas the hamster fibroma contained about 150 incomplete BPV genome equivalents per diploid cell. Thermal denaturation of in vitro labeled BPV DNA which reassociated in the presence of the two tumor DNA preparations indicated less than 1.5% base pair mismatching.