Tumoración en la pared abdominal / Abdominal wall tumor

El hematoma de la vaina de los rectos es una complicación rara secundaria a la toma de tratamiento anticoagulante y debida a la lesión muscular o rotura de las arterias epigástricas o de sus ramas pudiendo estar asociado a diversos factores. El 'gold standard' para el diagnóstico es la tomografía computarizada. La cirugía es el tratamiento reservado para los casos no resueltos con manejo conservador ni con embolización. A continuación presentamos un caso de una paciente en el postoperatorio de cirugía plástica

The rectus sheath haematoma is a rare complication secondary to taking anticoagulant therapy and due to muscle injury or breakage of the epigastric arteries or their branches may be associated with several factors. The 'gold standard' for the diagnosis is the computed tomography. Surgery is reserved for cases unresolved with conservative management or with embolization treatment. Here is a case of a patient after plastic surgery

The carcinogenic effect of various multi-walled carbon nanotubes (MWCNTs) after intraperitoneal injection in rats.

BACKGROUND: Biological effects of tailor-made multi-walled carbon nanotubes (MWCNTs) without functionalization were investigated in vivo in a two-year carcinogenicity study. In the past, intraperitoneal carcinogenicity studies in rats using biopersistent granular dusts had always been negative, whereas a number of such studies with different asbestos fibers had shown tumor induction. The aim of this study was to identify possible carcinogenic effects of MWCNTs. We compared induced tumors with asbestos-induced mesotheliomas and evaluated their relevance for humans by immunohistochemical methods. METHODS: A total of 500 male Wistar rats (50 per group) were treated once by intraperitoneal injection with 109 or 5 × 109 WHO carbon nanotubes of one of four different MWCNTs suspended in artificial lung medium, which was also used as negative control. Amosite asbestos (108 WHO fibers) served as positive control. Morbid rats were sacrificed and necropsy comprising all organs was performed. Histopathological classification of tumors and, additionally, immunohistochemistry were conducted for podoplanin, pan-cytokeratin, and vimentin to compare induced tumors with malignant mesotheliomas occurring in humans. RESULTS: Treatments induced tumors in all dose groups, but incidences and times to tumor differed between groups. Most tumors were histologically and immunohistochemically classified as malignant mesotheliomas, revealing a predominantly superficial spread on the serosal surface of the abdominal cavity. Furthermore, most tumors showed invasion of peritoneal organs, especially the diaphragm. All tested MWCNT types caused mesotheliomas. We observed highest frequencies and earliest appearances after treatment with the rather straight MWCNT types A and B. In the MWCNT C groups, first appearances of morbid mesothelioma-bearing rats were only slightly later. Later during the two-year study, we found mesotheliomas also in rats treated with MWCNT D - the most curved type of nanotubes. Malignant mesotheliomas induced by intraperitoneal injection of different MWCNTs and of asbestos were histopathologically and immunohistochemically similar, also compared with mesotheliomas in man, suggesting similar pathogenesis. CONCLUSION: We showed a carcinogenic effect for all tested MWCNTs. Besides aspect ratio, curvature seems to be an important parameter influencing the carcinogenicity of MWCNTs.

Haematogenous abdominal wall metastasis of differentiated, alpha-fetoprotein-negative hepatocellular carcinoma after previous antiandrogen therapy within a site of lipoma manifestation since childhood.

BACKGROUND: Cases with subcutaneous metastasis of differentiated hepatocellular carcinoma to the abdominal wall without prior seeding as a consequence of local interventions with a negative or normal alpha-fetoprotein level in the serum are extremely rare. CASE REPORT: This is the first report of a case with AFP-negative, differentiated hepatocellular carcinoma metastasis to the abdominal wall within a pre-existing subcutaneous lipoma since childhood after antiandrogen therapy with leuprorelin and buserelin acetate for prostate cancer without seeding. METHODS: Clinical features including histology, immunohistochemistry, clinical course and surgical approach are presented. RESULTS: Histological examination revealed a hepatocellular carcinoma with a trabecular and pseudoglandular growth pattern with moderately atypical hepatocytes with multifocal bile formation within a lipoma. The postoperative course of abdominal wall reconstruction with a monocryl-prolene mesh and a local flap after potentially curative resection was uncomplicated. DISCUSSION AND CONCLUSION: It may be that previous antiandrogen treatment for prostate carcinoma contributed to the fact that our patient developed alpha-fetoprotein-negative and androgen receptor-negative subcutaneous abdominal wall metastasis within a pre-existing lipoma since childhood.

Desmoplastic small round-cell tumor: an adult with previous exposure to agent orange.

Desmoplastic small round-cell tumor is an uncommon, highly aggressive tumor with a predilection for pediatric age groups and young adults. It is very unusual in the elderly population. Although Agent Orange has been associated with soft-tissue sarcoma, an association with desmoplastic small round-cell tumor has not been reported. A 52-year-old male presented with abdominal distention, dyspnea, and a 9 kg weight loss. Prior history was significant for hepatitis C and diabetes. He was a Vietnam veteran and he admitted being exposed to Agent Orange. On physical examination, the abdomen was distended and tense. Computed tomography scan of the chest, abdomen and pelvis demonstrated extensive mediastinal and retroperitoneal adenopathy, diffuse omental masses and extensive pleural, intra-abdominal and pelvic ascites. Omental core needle biopsy was consistent with desmoplastic small round-cell tumor based on morphology and immunohistochemistry. He responded poorly to chemotherapy with high-dose cyclophosphamide, doxorubicin and vincristine and died 5 months after presentation secondary to neutropenic sepsis despite G-CSF support and antibiotics.

Absence of carcinogenic response to multiwall carbon nanotubes in a 2-year bioassay in the peritoneal cavity of the rat.

Toxicological investigations of carbon nanotubes have shown that they can induce pulmonary toxicity, and similarities with asbestos fibers have been suggested. We previously reported that multiwall carbon nanotubes (MWCNT) induced lung inflammation, granulomas and fibrotic reactions. The same MWCNT also caused mutations in epithelial cells in vitro and in vivo. These inflammatory and genotoxic activities were related to the presence of defects in the structure of the nanotubes. In view of the strong links between inflammation, mutations and cancer, these observations prompted us to explore the carcinogenic potential of these MWCNT in the peritoneal cavity of rats. The incidence of mesothelioma and other tumors was recorded in three groups of 50 male Wistar rats injected intraperitoneally with a single dose of MWCNT with defects (2 or 20 mg/animal) and MWCNT without defects (20 mg/animal). Two additional groups of 26 rats were used as positive (2 mg UICC crocidolite/animal) and vehicle controls. After 24 months, although crocidolite induced a clear carcinogenic response (34.6% animals with mesothelioma vs. 3.8% in vehicle controls), MWCNT with or without structural defects did not induce mesothelioma in this bioassay (4, 0, or 6%, respectively). The incidence of tumors other than mesothelioma was not significantly increased across the groups. The initial hypothesis of a contrasting carcinogenic activity between MWCNT with and without defects could not be verified in this bioassay. We discuss the possible reasons for this absence of carcinogenic response, including the length of the MWCNT tested (< 1 mum on average), the absence of a sustained inflammatory reaction to MWCNT, and the capacity of these MWCNT to quench free radicals.

'Proximal-type' epithelioid sarcoma: is Agent Orange still at large?

BACKGROUND AND AIMS: Proximal-type epithelioid sarcomas of the perineum are extremely rare. The authors provide an overview of this condition in relation to the history of exposure to Agent Orange. PATIENT AND METHODS: A 54-year-old man presented with a rapidly growing perineal subcutaneous mass that was shown to be a proximal-type epithelioid sarcoma. The case is discussed. An Internet Medline search was performed and the current literature reviewed. RESULTS: Only 4 primary perineal sarcomas have been described in the literature. Epithelioid sarcomas are uncommon, aggressive tumours with a propensity for locoregional recurrence. They are recognised by the US Veterans Affairs department as linked to exposure to Agent Orange, an organochlorine defoliant containing the contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). However, the role of Agent Orange in sarcomagenesis is still controversial. CONCLUSION: Unusual soft tissue swellings in a background of chemical exposure should be investigated thoroughly with a view to early, appropriate treatment.

Carcinogenicity studies after intraperitoneal injection of two types of stone wool fibres in rats.

A summary is given of the pathology results after intraperitoneal (i.p.) injection in rats of insulation wool HT, representing the new biosoluble types. The pathology results are compared with a previously conducted i.p. study with traditional stone wool D6 (with similar chemical composition to MMVF21). The HT fibre is characterized by a relatively high content of aluminium and a relatively low content of silica compared to MMVF21. HT has a high in vitro dissolution rate at pH 4.5, a relatively low dissolution rate at pH 7.5 and is less biopersistent than the MMVF21 fibre. Female Wistar rats received a dose of 2 x 10(9) WHO HT fibres by i.p. injection. The fibres had been size-selected to be largely rat respirable. The negative control group was exposed to saline. Following exposure, the animals were maintained until survival in one group fell below 20%. At this time, all animals were killed. All animals were subjected to a necropsy examination; any gross abnormalities observed at necropsy were subjected to histopathological examination. In addition, histopathology was carried out on a predefined list of tissues. The incidences of lesions and survival in the control and fibre dosed animals were compared using appropriate statistical methods to determine whether the dosed animals showed adverse effects on survival or a positive carcinogenic response. The main protocol for the previously conducted study with D6 (MMVF21) was similar, but the animals were maintained as long as they survived, and the WHO fibre dose was lower. The results of the comparative study showed a marked difference in the i.p. pathogenicity of D6 (MMVF21) and HT in terms of their carcinogenic potential. D6 (MMVF21) caused a statistically significant increase of mesotheliomas in the peritoneal cavity compared to the negative control, but the HT fibre did not cause any mesotheliomas or any increase in other tumour types.

Fiber-specific molecular features of tumors induced in rat peritoneum.

Molecular markers such as mutational spectra or mRNA expression patterns may give some indication of the mechanisms of carcinogenesis induced by fibers and other carcinogens. In our study, tumors were induced by application of crocidolite asbestos or benzo[a]pyrene (B[a]P) to rat peritoneum. DNA and RNA of these tumors were subjected to analysis of point mutations and to investigation of mRNA expression patterns. With both assays we found typical features depending on the type of carcinogen applied. The analysis of point mutations in the tumor suppressor gene p53 revealed mutations in the B[a]P-induced tumors. However, in the tumors induced by crocidolite asbestos that were of the same tumor type as those induced by B[a]P, mutations in p53 were not detectable. Every mutation detected on the DNA level causes an amino acid substitution within one of the functional domains of the tumor suppressor protein. Therefore, these mutations seem to be of biological relevance for tumor progression and indicate a difference in the carcinogenesis regarding the type of the carcinogenic substance. An additional specificity of crocidolite-induced tumors was detectable by analyzing the mRNA expression of the tumor suppressor gene WT1, which is known to be expressed in human mesothelial and mesothelioma cells. A relatively high amount of WT1 mRNA was measured by quantitative competitive reverse transcription-polymerase using RNA extracted from crocidolite-induced tumors. However, WT1 seems to be expressed on a rather low level in tumors induced by B[a]P.

T25: a simplified carcinogenic potency index: description of the system and study of correlations between carcinogenic potency and species/site specificity and mutagenicity.

A simplified carcinogenic potency index, the T25, is proposed as a practical method for the inclusion of potency considerations in carcinogen classification systems. The T25 is the chronic daily dose in mg per kg bodyweight which will give 25% of the animals tumours at a specific tissue site, after correction for spontaneous incidence, within the standard life span of that species. Calculated T25 values of a set of 113 US National Cancer Institute/National Toxicology Program (NC/NTP) carcinogens showed excellent correlation (correlation coefficient 0.96, P < 0.0001) with the carcinogenic potency index TD50 of Peto et al. (1984). The mean of T25 values for 51 transspecies, multiple common site NCI/NTP carcinogens were 10-fold lower than those for 62 NCI/NTP single species, single site carcinogens. For these 113 carcinogens, the mean T25 values were approximately 3-fold lower for agents that were also mutagenic in Salmonella compared to the non-mutagenic agents.

Results of current intraperitoneal carcinogenicity studies with mineral and vitreous fibres.

The study includes some 50 groups of male or female Wistar rats tested in three series. Except for one untreated group and 3 vehicle control groups, the animals were injected intraperitoneally (i.p.) once or repeatedly with dust suspensions and then examined, after lifetime observation up to 30 months, for tumours in the abdominal cavity. 1 granular dust (silicon carbide), 2 asbestos dusts (crocidolite, tremolite) and 11 vitreous fibre dust samples were administered. 5 of the vitreous fibre types were fine fibre fractions from 4 commercial insulation wools and 1 experimental wool, the others were prepared by milling glass microfibres, which have, per se, a small diameter range. The dosage per rat differed over a wide range in accordance with experience from earlier studies. The lowest dose was 0.04 x 10(9) crocidolite fibres in 0.5 mg dust, and the highest amounted to 20 x 10(9) glass fibres in 1000 mg divided into 40 weekly injections. Two mesotheliomas were found in a total of 395 rats treated with saline or granular silicon carbide (250 or 1000 mg). Eleven fibre dusts produced dose-dependent mesotheliomas at rates of up to 97 %, but the calculated fibre number > 5 micrometers in length required for inducing a 25 % tumour risk differed between the fibre samples tested in the relation of 1 to about 1000. UICC-like crocidolite heads the ranking order; the glass fibre B-01, which possesses a low durability in the body, ends it together with a rather thin sample of glass fibre type B-09. The stone fibre MMVF-21 takes a high place in the ranking order, similar to the tremolite sample. The results correspond to those of earlier i.p. tests.

Differential diagnosis of malignant tumours in the abdominal cavity of rats after intraperitoneal injection of crocidolite or benzo[a]pyrene.

In our investigation (i.p. test), crocidolite and benzo[a]pyrene, both caused a progression from initially reactive, then autonomously transformed proliferation of myofibroblasts and undifferentiated mesenchymal cells to malignant, multidirectionally differentiated (desmin and ED-1 positive) fibro-histiocytic tumours. Immunohistochemically these tumours showed no morphological characteristics (for example co-expression of vimentin and keratin in spindle-shaped tumour cells) of human asbestos-associated malignant mesotheliomas. On the other hand many tumour cells induced by crocidolite and benzo[a]pyrene had an ultrastructural appearance resembling fibroblasts and myofibroblasts. These have been demonstrated in only a few desmoplastic and sarcomatous mesotheliomas in human beings. None of the tumours revealed the typical ultrastructural features of epitheloid or transitional mesotheliomas. Apparently, both carcinogenic substances induce the transformation of undifferentiated pluripotent mesenchymal cells in rat peritoneum, regardless of their localization in the submesothelial compartment or perivascular connective tissue (preferentially after crocidolite application) or in the connective tissue pseudocapsule of major benzo[a]pyrene containing beeswax/tricaprylin depots in the mesometrium and mesenterial fatty tissue. In this way asbestos fibres in this animal experiment do not seem to induce an arrest in differentiation of intermediate or immature mesothelial cells as supposed formerly, but rather affect undifferentiated mesenchyme cells and myofibroblasts. This is an explanation for the immunohistochemical expression of markers of muscular differentiation in these tumour cells, which is known to occur in human malignant fibro-histiocytic tumours. If supplementary immunohistochemical investigations with different keratin antibodies also fail to confirm the mesothelial differentiation of the tumours induced in our i.p. test, the decision to call them "mesotheliomas" should be reconsidered. Further immuno-transmission-electron microscopical investigations with intermediate filament or macrophage antibodies are needed to clarify whether the term malignant "fibrohistiocytic sarcoma", "mesenchymoma" or "mesothelioblastoma" would be more correct from the morphological point of view.

Phenobarbital promotes the development of adenocarcinomas in the accessory sex glands of MNU-inoculated L-W rats.

Aged Lobund-Wistar (L-W) rats develop: (i) spontaneous and induced metastasizing adenocarcinomas in the prostate and seminal vesicle (P-SV) complex; and (ii) spontaneous hepatomas and hepatocarcinomas. Within the time-frame of 14 months, similar adenocarcinomas were induced in the P-SV complex in 70-90% of younger L-W rats by a single i.v. inoculation of methylnitrosourea (MNU) which was followed by slow release s.c. implants of testosterone propionate (TP). Within the same time-frame, neither MNU nor TP alone induced significant incidences of P-SV tumors; and untreated control L-W rats were disease-free. Methylnitrosourea or TP and combinations thereof did not induce liver tumors. However, when MNU-inoculated L-W rats were fed phenobarbital (PB), they developed (i) metastasizing adenocarcinomas in the P-SV complex and (ii) altered cellular foci and nodules in the livers. Methylnitrosourea induced a high incidence of benign lung adenomas which progressed to lung cancers in numbers which were of marginal significance. Thus, dormant MNU-initiated cells in the P-SV complex were activated by phenobarbital, to produce adenocarcinomas in that complex.

[Acute leukemia as secondary neoplasms in children with advanced lymphomas]. / Leucemias agudas como neoplasias secundárias em crianças portadoras de linfomas avançados.

In 1985 a new treatment regimen for advanced non-Hodgkin's lymphoma was started in the "Instituto da Criança-HC-FMUSP". The final results are remarkably better than those achieved with former programs. Two cases of children who developed a second neoplasm after the therapy was completed are described and discussed.

Fatal abdominal thorotrast granuloma.

We report a case of fatal abdominal thorotrast granuloma seen in a 65-year-old man who had undergone a femoral angiography of thorotrast with some accidental extravasation 49 years previously. As the thorotrast granuloma gradually increased in size, it caused ureteral obstruction, venous thrombosis, and perforation of the urinary bladder and rectum. Symptomatic abdominal thorotrast granuloma is quite rare and this is the first reported case of the granuloma associated with perforation through the urinary bladder and rectum.