Superficial Angiomyxomas Frequently Demonstrate Loss of Protein Kinase A Regulatory Subunit 1 Alpha Expression: Immunohistochemical Analysis of 29 Cases and Cutaneous Myxoid Neoplasms With Histopathologic Overlap

Superficial angiomyxomas (SAMs) are benign cutaneous tumors that arise de novo and in the setting of the Carney complex (CC), an autosomal dominant disease with several cutaneous manifestations including lentigines and pigmented epithelioid melanocytomas. Although most SAM do not pose a diagnostic challenge, a subset can demonstrate histopathologic overlap with other myxoid tumors that arise in the skin and subcutis. Traditional immunohistochemical markers are of limited utility when discriminating SAM from histopathologic mimics. Since protein kinase A regulatory subunit 1 alpha (PRKAR1A) genetic alterations underlie most CC cases, we investigated whether SAM demonstrate loss of PRKAR1A protein expression by immunohistochemistry. In our series, 29 SAM, 26 myxofibrosarcoma, 5 myxoid dermatofibrosarcoma protuberans, 11 superficial acral fibromyxomas, and 18 digital mucous cysts were characterized. Of the 29 SAM examined in this study, 1 was associated with documented CC in a 5-year-old girl. SAM tended to arise in adults (mean 49.7 y; range: 5 to 87 y). Loss of PRKAR1A was seen in 55.2% of cases (16/29) and had a male predilection (87.5%, 12/16). PRKAR1A-inactivated SAM demonstrated significant nuclear enlargement (100%, 16/16 vs. 23.1%, 3/13), multinucleation (81.3%, 13/16 vs. 23.1%, 3/13), and presence of neutrophils (43.8%, 7/16 vs. 0%, 0/13). In contrast, PRKAR1A was retained in all cases of myxofibrosarcoma (100%, 26/26), myxoid dermatofibrosarcoma protuberans (100%, 5/5), superficial acral fibromyxomas (100%, 11/11), and digital mucous cyst (100%, 18/18). Taken together, PRKAR1A loss by immunohistochemistry can be used as an adjunctive assay to support the diagnosis of SAM given the high specificity of this staining pattern compared with histopathologic mimics.

Increasing expression of serine protease matriptase in ovarian tumors: tissue microarray analysis of immunostaining score with clinicopathological parameters

Matriptase is a type II transmembrane serine protease expressed by cells of surface epithelial origin, including epithelial ovarian tumor cells. Matriptase cleaves and activates proteins implicated in the progression of cancer and represents a potential prognostic and therapeutic target. The aim of this study was to examine the expression of matriptase in ovarian tumors and to assign clinicopathological correlations. Immunohistochemical analysis of matriptase was performed in tissue microarrays of 164 ovarian neoplasms including 84 serous adenocarcinomas, 23 mucinous adenocarcinomas, 10 endometrioid adenocarcinomas, six yolk sac tumors, 12 clear cell carcinomas, six dysgerminomas, eight granulosa cell tumors, four transitional cell carcinomas, five fibromas, and six Brenner tumors. All ovarian tumors except the fibromas and Brenner tumors showed significant expression of matriptase. The matriptase scores were significantly higher in the tumors than in their nontumor counterparts (304+/-26 for serous adenocarcinoma; 361+/-28 for mucinous adenocarcinoma; 254+/-17 for endometrioid adenocarcinoma; 205+/-19 for yolk sac tumor; 162+/-16 for clear cell carcinoma; 109+/-11 for dysgerminoma; 105+/-9 for granulosa cell tumor; and 226+/-18 for transitional cell carcinoma). Matriptase scores in serous adenocarcinoma were correlated with TNM stage and FIGO stage. Our findings demonstrate for the first time that matriptase is overexpressed in many malignant ovarian tumors. It may be a novel biomarker for diagnosis and treatment of malignant ovarian tumors.

Matrix metalloproteinase expression is related to angiogenesis and histologic grade in spindle cell soft tissue neoplasms of the extremities

We defined the immunocytochemical expression of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) in benign soft tissue neoplasms, fibromatoses, and sarcomas, together with the activity of gelatinase MMPs and TIMPs measured by zymography and reverse zymography in a subset of cases. The most strongly expressed MMP in all tumors was MMP-1, with weaker expression of MMP-10, MMP-11, and MMP-14 in most tumors. Nuclear expression of MMP-1, MMP-8, and MMP-13 was an unusual feature. TIMP-2 was expressed in all tumors, with stronger expression in fibromatoses than in sarcomas. Fibromatoses and high-grade sarcomas showed greater MMP-1 expression than other groups, and endothelial MMP-2 expression was more extensive in sarcomas. Differences in MMP and TIMP expression might be linked to the biologic behavior of soft tissue neoplasms. The activation of endothelial MMP-2 linked to widespread MMP-14 expression provides a mechanism for sarcomas to modulate their matrix and facilitate angiogenesis.

Matrix Metalloproteinase Activity Modulates Tumor Size, Cell Motility, and Cell Invasiveness in Murine Aggressive Fibromatosis

Matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) regulate the degradation of extracellular matrix components and play important roles in the progression of select neoplastic processes. The locally invasive soft tissue tumor, aggressive fibromatosis (also called desmoid tumor), is caused by mutations resulting in beta-catenin-mediated T-cell factor (tcf)-dependent transcriptional activity. Because beta-catenin can regulate MMP expression, we investigated the expression of several MMPs and TIMPs in aggressive fibromatosis tumors that develop in Apc+/Apc1638N mice. Mmp-3 and Timp-1 were differentially regulated (5-fold and 0.5-fold, respectively) in tumors compared with normal fibrous tissue. Conditioned media from tumor cells showed an increased ability to degrade collagen, and inhibition of MMPs using GM6001 decreased the ability of the tumor cells to invade through Matrigel. Both the treatment of Apc/Apc1638N mice with GM6001 or crossing with a transgenic mouse that overexpresses Timp-1 resulted in a significant reduction in tumor volume. Surprisingly, overexpression of Timp-1 also resulted in a 50% increase in tumor number. Although TIMP-1 can induce growth stimulatory effects in some cell types, we found no difference in proliferation or apoptosis rate in cells from tumors that developed in the Timp-1-transgenic mice compared with mice that did not express the Timp-1 transgene, suggesting that TIMP-1 promotes aggressive fibromatosis tumor formation through an alternate mechanism. These data suggest that MMPs play a crucial role in regulating the invasiveness of mesenchymal cells and in modulating aggressive fibromatosis tumor progression. Because this is a locally invasive tumor, MMP inhibition could slow tumor growth and may prove to be an effective adjuvant therapy.

Immunohistochemical analysis of anaplastic lymphoma kinase expression in deep soft tissue calcifying fibrous pseudotumor: evidence of a late sclerosing stage of inflammatory myofibroblastic tumor?

Calcifying fibrous pseudotumor (CFT) is a rare benign soft tissue lesion composed of dense hyalinized fibrous tissue containing bland spindle-shaped cells admixed with a lymphoplasmacytic infiltrate and foci of dystrophic and often psammomatous calcifications. It has been suggested that CFT represents a late sclerosing stage of inflammatory myofibroblastic tumor (IMT). Recently, clonal cytogenetic abnormalities involving the anaplastic lymphoma kinase (ALK) gene on chromosome 2p have been identified in IMT, particularly those arising in deep soft tissue sites. We evaluated seven cases of deep soft tissue CFT diagnosed at the Cleveland Clinic Foundation and the University of Florida with available paraffin-embedded blocks using a monoclonal antibody to ALK (Dako, Carpenteria, CA) and a modified avidin-biotin complex method. The cohort included six women and one man with a median age at diagnosis of 43 years (range, 26 to 67 years). Sites of CFT included mesentery (3), peritoneum (1), omentum (1), serosa of small bowel (1), and anterior mediastinum (1). Immunohistochemically, only one case showed focal staining for ALK. The remaining six cases were negative, with appropriate positive and negative control staining. In conclusion, unlike IMT, CFT in deep soft tissue locations rarely expresses ALK by immunohistochemistry, suggesting that CFT is a different clinicopathologic entity than IMT, as opposed to representing a "burned out" IMT. Ann Diagn Pathol 5:10-14, 2001.

Differential telomerase activity, expression of the telomerase catalytic sub-unit and telomerase-RNA in ovarian tumors

Telomerase activity has been found in a variety of malignant tumors but only rarely in benign tumors or normal tissues. In this study, we investigated telomerase activation in 37 ovarian tumors, including benign, borderline and malignant neoplasms. Telomerase activity was detected using the telomeric repeat amplification protocol (TRAP) in 13/16 ovarian carcinomas, 9/10 borderline tumors and 3/11 cystadenomas/fibromas. mRNA expression of the putative human telomerase catalytic sub-unit gene (hTERT) was detected by RT-PCR in 14/15 ovarian carcinomas, 8/10 borderline tumors and 4/11 cystadenomas/fibromas. In situ hybridization was performed to evaluate telomerase-RNA (hTR) expression in the corresponding paraffin-embedded tumors. Variable expression levels of hTR were found over neoplastic tumor cells. The highest levels of hTR expression were found predominantly in ovarian carcinomas. Although the amount of telomerase activity varied, significantly high levels of telomerase activity were found predominantly in ovarian carcinomas. hTERT mRNA expression was closely associated with telomerase activity. These findings suggest that up-regulation of hTERT and hTR is important for telomerase activation during malignant-tumor progression. Telomerase activation might therefore be a valuable diagnostic parameter that could help to identify potentially progressive lesions. However, the diagnostic and therapeutic implications of telomerase activation need to be clarified in clinical trials. Int. J. Cancer (Pred. Oncol.) 84:426-431, 1999.

"Aberrant elastic" in elastofibroma: an immunohistochemical and ultrastructural study

Elastofibroma is a rare lesion characterized by the presence of abundant abnormal elastic fibers with a unique morphology, fibroblastic proliferation, and collagen deposition. Whether the altered morphology of the elastic fibers is a degenerative phenomenon or is due to abnormal elastogenesis is controversial. We studied fetal skin and three cases of elastofibroma by light microscopy and immunohistochemistry using an antibody to lysozyme, and one case of elastofibroma by electron microscopy (EM). Our previous studies have shown that normal elastic fibers in adult skin do not stain for lysozyme whereas abnormal elastic fibers in solar elastosis and pseudoxanthoma elasticum react positively for lysozyme. In the fetal skin and all three cases of elastofibroma the elastic fibers were negative for lysozyme. EM showed the abnormal flowerlike configuration of the elastic fibers, which consisted of a central core of normal or degenerating elastin surrounded by radiating spokes of granular and filamentous material of variable electron densities, suggesting that the structure and organization of the microfibrils is abnormal. The absence of lysozyme in the aberrant elastic did not differentiate whether there was excessive production of fetal or adult elastic. However, the excessive amount of microfibrils seen at the ultrastructural level suggests that there may be excessive fetal elastic production. The elastic fibers were intimately related to the fibroblasts and were often present within their caveolae, suggesting that the abnormal elastic fibers are produced by the fibroblast. Our study suggests that abnormal elastogenesis with subsequent degeneration plays a role in the production of the abnormal elastic fibers in elastofibroma.

Expression of 72 kilodalton type IV collagenase (gelatinase A) in benign and malignant ovarian tumors

BACKGROUND

72 Kilodalton (kd) type IV collagenase is a matrix metalloproteinase that specifically cleaves type IV collagen molecules. The enzyme has been postulated to have an important role in the invasion and spread of malignant tumors.

EXPERIMENTAL DESIGN

In situ hybridization was used to study the expression of the 72 kd type IV collagenase mRNA in 24 benign, 2 semimalignant, and 15 malignant ovarian tumors and in 5 metastases of ovarian serous adenocarcinomas. The results were correlated with the expression of the mRNA for the alpha 1(IV) chain of type IV collagen and with the corresponding immunohistochemical distribution of the enzyme.

RESULTS

The results showed that the more malignant an ovarian tumor was, the more clearly mRNA expressions for both 72 kd type IV collagenase and the alpha 1(IV) chain could be detected in tumor cells. The expression of both types of mRNAs was localized within the cells of tumor stroma and occurred mainly in fibroblasts and vascular endothelial cells. Epithelial tumor cells only rarely expressed these mRNAs. Immunohistochemical stainings localized the 72 kd collagenase as well to the stromal cells as to the epithelial cells of both benign and malignant tumors.

CONCLUSIONS

The findings indicate that genes for the 72 kd type IV collagenase and for its substrate are simultaneously active in the same cells of the tumor stroma. The difference in the in situ hybridization and immunohistochemical findings could be explained by a possible variation in the metabolic balance between synthesis and accumulation of the protein in different cell types. It can also be proposed that the activity of the 72 kd type IV collagenase would be mediated through a receptor-like mechanism present on epithelial cells which could bind the 72 kd type IV collagenase synthesized elsewhere. There is also a possibility that the gelatinolytic activity of the mesenchymally synthesized 72 kd type IV collagenase would be consumed to degrade extracellular matrix proteins other than basement membranes.

Expression of 72 kilodalton and 92 kilodalton type IV collagenase in malignant fibrous histiocytomas and dermatofibromas

BACKGROUND

In previous studies, it has been shown that the stromal cells of epithelial tumors are capable of synthesizing 72 and 92 kilodalton (kd) type IV collagenase mRNA. The mRNA synthesis of these collagenases in mesenchymal tumors has not been extensively studied, however. This study was undertaken to explore the synthesis of 72 and 92 kd type IV collagenase mRNAs in malignant and benign fibrous histiocytomas and its correlation with the known biologic behavior of these tumors.

EXPERIMENTAL DESIGN

The synthesis of 72 kd and 92 kd type IV collagenase mRNA was studied in 10 malignant fibrous histiocytomas (MFHs) and 7 dermatofibromas using in situ hybridization methods. The tumors were also studied with a commercial monoclonal antibody to the 72 kd type IV collagenase. Additionally, three dermatofibromas were studied with an antibody to the 92 kd type IV collagenase. The media of three cell lines (MFH, dermatofibroma and skin fibroblast cell line) were also analyzed by zymography assay.

RESULTS

The results revealed mRNA for the 72 kd and 92 kd collagenases in tumor cells of both MFHs and dermatofibromas. Also intracytoplasmic immunoreactivity for the 72 kd type IV collagenase could be seen in all the tumors. In the zymography assay, 72 kd type IV collagenase activity was detected in the culture media of all the cell lines tested, but activity for the 92 kd enzyme was only seen in the MFH. However, immunoreactivity for the antibody to the 92 kd type IV collagenase was also seen in dermatofibromas.

CONCLUSIONS

The findings indicate that MFHs and dermatofibromas produce type IV collagenases. The synthesis of the mRNAs for both 72 kd and 92 kd type IV collagenase was quantitatively similar in MFHs and dermatofibromas indicating that there is no correlation between the biologic behavior of the tumors and the synthesis of these substances. Therefore, additional factors other than synthesis of type IV collagenases by tumor cells, must be involved in the process of spread and invasion of tumor cells into the neighbouring tissues.

Phosphoamino acid phosphatases in normal and cancerous tissues of the human uterus, cervix and ovary

The activities of phosphoamino acid phosphatases were measured in human myometrium and fibroma and normal and cancerous tissues of the cervix and ovary. Phosphoserine and phosphothreonine phosphatases were detected only in myometrium and fibroma and the values were relatively low. Phosphotyrosine phosphatase activities in myometrium and fibroma fell within a similar range; this was also the case for ovary and ovarian carcinoma, whereas values for cervical tumours were significantly higher than for normal cervix. Activities of phosphotyrosine phosphatase in serum from patients with cervical or other tumours were, in most cases, within the range of values obtained for normal serum.

Matrix vesicles in bone tumors. Ultrastructural analysis and their significance in neoplastic bone formation

Bone tumors were categorized into alkaline phosphatase (ALPase)-positive (2 ossifying fibromas, 1 benign osteoblastoma and 16 osteosarcomas) and negative (2 chondromas, 2 chondrosarcomas, 3 non-ossifying fibromas, 2 malignant fibrous histiocytomas and 6 giant cell tumors of bone) groups. Production and distribution of matrix vesicles (MVs) in the tumor tissues were examined to clarify their role in neoplastic bone formation. Four distinct types of MV were isolated primarily in ALPase positive bone tumors: empty, amorphous, crystalline and ruptured MVs. They were formed by budding off from the cytoplasmic projections of the osteoblastic tumor cells. The significance of differences in the production rate of MVs between ALPase-positive and negative bone tumors was investigated in view of the predominantly high production of MVs in ALPase-positive bone tumors. Many more mature MVs (crystalline and ruptured) were observed in the osteoblastic lesions of osteosarcoma than in the fibroblastic and MFH-like lesions, suggesting an intimate relationship with maturation and differentiation of the osteoblastic tumor cells. The above findings indicate that production of MVs is one of the diagnostic parameters for osteoblast-derived bone tumors, as well as ALPase activity, and that vesicle-induced mineralization is a major mineralization mechanism in neoplastic bone formation.

Pyruvate kinase activity and isozyme composition in normal fibrous tissue and fibroblastic proliferations

Pyruvate kinase (PK) was studied in 57 fibroblastic and fibrohistiocytic proliferations and normal fibrous tissue (n = 10). The specific activity was significantly increased in malignant tumors (1.67 +/- 0.25) compared with normal tissue (0.26 +/- 0.04; P less than 0.001) and benign proliferations (0.52 +/- 0.05; P less than 0.005). Although an overlap exists between aggressive fibromatosis and the benign group, high values of PK activity are indicative of Grade 2 and 3 malignancy. Significant shifts in isozyme pattern, favoring the expression of K-type subunits were found in tumors with a metastasizing potential and aggressive fibromatosis. These changes in the isozyme pattern of PK in aggressive fibromatosis may act as another argument to place them in the category of malignant fibroblastic tumors.

Immunohistochemical study of 3 beta-hydroxysteroid dehydrogenase in sex cord-stromal tumors of the ovary

3 beta-Hydroxysteroid dehydrogenase (3 beta-HSD), which converts pregnenolone to progesterone, was localized immunohistochemically in 18 thecomas, 23 fibromas, 5 granulosa-cell tumors, 5 sclerosing stromal tumors, and 2 steroid-cell tumors. Immunohistochemical study of estrogen, progesterone, and testosterone was also performed in serial sections of thecomas and fibromas. In thecomas, immunoreactivity of 3 beta-HSD was observed only in luteinized theca cells and thecomatous tumor cells with abundant pale to vacuolated cytoplasm but not in spindled tumor cells and thecomatous tumor cells with small to moderate amounts of pale to vacuolated cytoplasm. Immunoreactivity of steroids was not observed in thecomas except for testosterone immunoreactivity in one case. No immunoreactivity of steroids or the enzyme was present in fibromas. No tumor cells were positive for 3 beta-HSD in any of the cases of granulosa-cell tumor examined. Immunoreactivity of 3 beta-HSD was present in cells in steroid-cell tumors and polygonal tumor cells with prominent cytoplasmic vacuoles in two cases of sclerosing stromal tumor. Thus, 3 beta-HSD can be a good immunohistochemical marker of steroidogenesis in functioning ovarian neoplasms.

Immunohistochemical studies of steroidogenic enzymes (aromatase, 17 alpha-hydroxylase and cholesterol side-chain cleavage cytochromes P-450) in sex cord-stromal tumors of the ovary

Aromatase, 17 alpha-hydroxylase, and cholesterol side-chain cleavage P-450 cytochromes (P-450AROM, P-450(17 alpha,) and P-450SCC, respectively) were immunohistochemically localized in nine granulosa cell tumors, 15 thecomas, ten Sertoli-Leydig cell tumors, two steroid cell tumors, five fibromas, and five sclerosing stromal tumors. In the thecomas, P-450SCC and P-450(17 alpha) were positive in luteinized theca cells and in cells with vacuolated cytoplasm, while P-450AROM was not observed. In the steroid cell tumors, all the P-450 cytochromes were intensely stained. P-450SCC and P-450(17 alpha) were present in cells with vacuolated cytoplasm in two cases of sclerosing stromal tumor. P-450AROM was weakly demonstrated in one of the granulosa cell tumors. P-450(17 alpha,) P-450SCC, and P-450AROM were all faintly stained in the Sertoli-Leydig cell tumors. No P-450 cytochrome immunoreactivity was observed in any fibroma.

Enzyme histochemical observation of fibrohistiocytic tumors

The reactivity of lysosomal enzymes in 17 fibrohistiocytic tumors were examined histochemically to evaluate the histiocytic nature of the tumors. The lysosomal enzymes examined were acid phosphatase (Ac-P), non-specific esterase (NS-E), beta-glucuronidase (beta-GL), and N-acetyl-beta-glucosaminidase (N-GA). The tumors examined were eight malignant fibrous histiocytomas (MFH) (i.e., five common types, two myxoid types, and one inflammatory type), one atypical fibroxanthoma of the skin (AFX), one dermatofibrosarcoma protuberans (DFSP), two giant cell tumors of the tendon sheath (GCT), and five dermatofibromas (DF). Seven of 8 MFH showed strong reactivity for all enzymes examined. Positive reactions were seen as evenly distributed granules in the cytoplasm of fibroblastic, histiocytic and giant cells in all types of the tumors. Almost all AFX, GCT, and DF showed moderate to strong reactivity. These findings suggest that these tumors were composed of cells with the enzymatic character of histiocytes. However, DFSP contained no cells giving a positive reaction, and thus its histiocytic nature could not demonstrated.

A quantitative histochemical study of glucose-6-phosphate dehydrogenase activity in premalignant and malignant lesions of human oral mucosa

The levels of glucose-6-phosphate dehydrogenase activity have been assayed by quantitative histochemistry in normal, benign, potentially malignant and carcinomatous lesions of human oral mucosa. Dysplastic epithelium showed a higher activity of this enzyme than did morphologically normal, benign hyperplastic and neoplastic lesions and this may be an aid to early diagnosis. The increases in glucose-6-phosphate dehydrogenase activity in dysplastic human oral epithelium are sufficient to warrant a longitudinal study to evaluate further the significance of these changes in the process of malignant transformation.

Immunohistochemical observation of intracytoplasmic lysozyme in proliferative and neoplastic fibrohistiocytic lesions

Distribution of intracytoplasmic lysozyme in proliferative and neoplastic fibrohistiocytic lesions and non fibrohistiocytic tumors was studied by immunoperoxidase technique on formalin fixed, paraffin-embedded sections. The cases examined were 161 fibrohistiocytic lesions and 86 non-fibrohistiocytic tumors. Contrary to our expectation, the lysozyme positive cells were found only in the minority of cases with fibrohistiocytic lesions. Cells positive for lysozyme were found only in 13 out of 100 cases of dermatofibroma, one out of 4 cases of xanthogranuloma and 8 out of 33 cases of malignant fibrous histiocytoma. Dermatofibrosarcoma protuberans and non-fibrohistiocytic tumors were negative for lysozyme. It is suggested that in proliferative fibrohistiocytic lesions, induction of lysozyme synthesis is weak or absent. Some malignant fibrous histiocytomas showed scattered lysozyme positive neoplastic cells, indicating their probable histiocytic origin or differentiation. On the other hand, evidence of histiocytic differentiation of dermatofibrosarcoma protuberans was not obtained using lysozyme immunohistiochemistry.

Immunohistochemical identification of lysozyme in cutaneous lesions of alleged histiocytic nature

Histiocytosis X, multicentric reticulohistiocytosis, juvenile xanthogranuloma, the "fibrous" type of dermatofibroma, dermatofibrosarcoma protuberans, and malignant fibrous histiocytoma are all characterized by dermal and/or subcutaneous infiltrates composed at least partially of cells having morphologic features suggestive of histiocytes. Paraffin-embedded tissues representing these conditions were stained for lysozyme (muramidase) with a peroxidase-antiperoxidase technic. The cells of juvenile xanthogranuloma were rich in lysozyme. Some of the cells of histiocytosis X showed a positive pattern, and the cells of the other three conditions were essentially negative. This study confirmed the histiocytic nature of juvenile xanthogranuloma and multicentric reticulohistiocytosis, supported the interpretation that there is a histiocytic component in the lesions of histiocytosis X, and cast some doubt on the alleged histiocytic nature of "fibrous" dermatofibroma, dermatofibrosarcoma protuberans, and malignant fibrous histiocytoma.

[Enzyme and histochemical studies of eye neoplasms in cattle. I. Enzyme and histochemical findings in papilloma and fibroma]

The activity of succinic dehydrogenase, adenosine triphosphatase, acid and alkaline phosphatase, lipase and nonspecific esterases in 12 tumors of the orbital region of cattle was studied.

The succinic dehydrogenase activity was not significantly different in papillomas and fibromas, as compared with that of the normal tissues of origin of the tumors. Topographical distribution of adenosine triphosphatase was directly correlated with the cell multiplication process, and thus with the tissues' needs for an energetic basis. The activity of adenosine triphosphatase and alkaline phosphatase was enhanced in the region of proliferating capillaries, and this was interpreted to indicate the tendency of these tumors to malignancy. The activity of lipase and the nonspecific esterases showed nonspecific oscillations in papillomas and fibromas as compared with that in the normal tissues.

Elastofibroma dorsi

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