[Tumors of the lymphatic vessel of the skin and soft tissue]

Case Report: Multiple Cavernous Pericardial Lymphangioma (Pericardial Lymphangiomatosis) in a Captive Peregrine Falcon (Falco peregrinus brookei)

A 12-year-old female peregrine falcon (Falco peregrinus brookei) from a private raptor breeding facility that presented a good body condition, died suddenly without showing previous symptoms. At necropsy, in the coelomic cavity, multiple cystic structures demarcated by a thin transparent wall and filled with a serous content were observed. They were firmly adhered to the cranial part of the epicardium and adjacent tissues and occupied the entire thoracic area of the coelomic cavity. Microscopically, emerging simultaneously from several areas the epicardium, multiple irregular channels and cystic spaces, lined by a single endothelial cell layer and separated by fibrovascular septa containing smooth muscle tissue, were observed. Immunohistochemical examination revealed that the neoplastic endothelial cells positively immunolabelled for the pan-endothelial marker factor VIII-related antigen but immunostained negative for cytokeratins (PCK26) while strong positivity for sarcomeric α-smooth muscle actin (α-SMA) was detected in the cystic walls. Based on the morphological and immunohistochemical findings, lesions were determined as consistent with a multiple cavernous pericardial lymphangioma, or pericardial lymphangiomatosis, a rare vascular neoplasm. The animal also showed a diffuse chronic perihepatitis, a necrotic area in the liver and foci of cartilaginous metaplasia and calcification in the aorta and vena cava. Literature review, particularly on the epidemiology of lymphangioma, demonstrated the rarity of this tumor in the different animal species and in this location, particularly in birds, being the first report of this type of tumor in a peregrine falcon.

Strong ERG Positivity in Papillary Intralymphatic Angioendothelioma of the Testis of a 24-Year-Old Male: A Case Report

Papillary intralymphatic angioendothelioma is a rare, low-grade neoplasm of lymphatic channels that usually presents intradermally or subcutaneously. We report the case of a 24-year-old male presenting with an isolated intratesticular palpable mass and symptoms of testicular pain. Preoperative ultrasound examination showed an irregular, heterogeneous mass. Subsequent surgery and pathologic assessment revealed a papillary intralymphatic angioendothelioma (PILA), formerly known as Dabska tumor within the lymphatic spaces.

Prox1 transcription factor as a marker for vascular tumors-evaluation of 314 vascular endothelial and 1086 nonvascular tumors

Prox1, a transcription factor important in the regulation and maintenance of the lymphatic endothelial phenotype, is consistently expressed in lymphangiomas and Kaposi sarcoma and has also been reported in Kaposiform hemangioendothelioma. However, information on its distribution in vascular tumors, such as angiosarcoma, is limited. In this study, we examined selected normal tissues and 314 vascular endothelial and 1086 nonvascular tumors to get an insight into the biology of these tumors and on potential diagnostic use of Prox1 as an immunohistochemical marker. In adult tissues, Prox1 was essentially restricted to lymphatic endothelia, with expression in subsets of pancreatic and gastrointestinal epithelia. However, it was also detected in embryonic liver and heart. Prox1 was consistently expressed in lymphangiomas, venous hemangiomas, Kaposi sarcoma, in endothelia of spindle cell hemangioma, Kaposiform hemangioendothelioma, and retiform hemangioendothelioma, and in half of epithelioid hemangioendotheliomas. It was present in most cutaneous angiosarcomas from different sites but was less commonly expressed in deep soft tissue and visceral angiosarcomas. In contrast, Prox1 was generally absent in capillary and cavernous hemangiomas. In positive hemangiomas and angiosarcomas it was coexpressed with podoplanin, another marker of the lymphatic endothelial phenotype. There was an inverse correlation with CD34 expression. The expression in mesenchymal nonendothelial neoplasm was limited. Prox1 was detected in 5 of 27 synovial sarcomas, specifically in the epithelia of biphasic tumors. Four of 16 Ewing sarcomas and 5 of 15 paragangliomas were also positive. All melanomas and undifferentiated sarcomas were negative. Among epithelial neoplasms, Prox1 was detected in 18 of 38 colonic carcinomas and 10 of 15 cholangiocarcinomas and in a minority of pulmonary, prostatic, and endometrial adenocarcinomas. The common Prox1 expression in angiosarcoma and its rare presence in nonvascular mesenchymal tumors make this marker suitable for the diagnosis of angiosarcoma and Kaposi sarcoma. However, the presence of Prox1 in some malignant epithelial tumors necessitates caution in applying Prox1 as a marker for vascular tumors. Common Prox1 expression in angiosarcoma may reflect the lymphatic endothelial phenotype in these tumors. Its patterns of expression in hemangiomas and angiosarcoma may be diagnostically useful and offer a new parameter in the biological classification of vascular tumors.

Pathogenesis of lymphangiomas

Based on various hypotheses concerning lymphangiogenesis published in the literature, different putative mechanisms of lymphangioma development are discussed including failure of the lymphatic system to connect with or separate from the venous system, abnormal budding of the lymphatic system from the cardinal vein, or acquired processes such as traumata, infections, chronic inflammations, and obstructions. Increasingly, the possible influence of lymphangiogenic growth factors on the development of lymphangiomas is discussed. The proved expression of different growth factors in the endothelium of lymphangiomas leads to new hypotheses regarding the pathogenesis of lymphangiomas. Thus, further studies on the lymphangiogenesis and the development of lymphangiomas will have to clarify as to whether lymphangiomas are true malformations or neoplastic in nature.

Acquired cutaneous lymphangiectasia with mesothelial cells reflux in a patient with cirrhotic ascites

A previously undescribed case of acquired cutaneous lymphangiectasias on the abdomen in a patient with cirrhotic ascites where peritoneal mesothelial cells refluxed in the skin is discussed. A 56-year-old man previously submitted to liver transplantation presented with vesiculobullous lesions on the developed as his cirrhotic ascites progressed. Histology showed dilated lymphatic channels in the upper dermis lined by a single, discontinuous layer of flattened, monomorphous endothelial cells with endoluminal papillary projections. In the deep reticular dermis, we observed irregular thin- often jagged-walled vascular channels lined by a single layer of bland endothelial cells, dissecting the collagen bundles. Vessels in the lumen were medium to large bizarre-shaped polygonal cells with abundant eosinophilic cytoplasm and hyperchromatic and irregular nuclei, arranged in small clusters or as solitary units, focally in close contact with the endothelial lining or free floating within vessel cavities. Immunohistochemistry indicated atypical intraluminal cells to be positive for calretinin, a specific marker for mesothelial cells. Pathophysiologic mechanisms and problems of differential diagnosis of this unique clinicopathologic entity are discussed.

Vascular proliferations of the skin after radiation therapy for breast cancer: Clinicopathologic analysis of a series in favor of a benign process

BACKGROUND

Cutaneous vascular proliferations that occur in the field of prior radiotherapy include angiosarcoma and small, cutaneous lesions with a pseudosarcomatous pattern that previously were reported as atypical vascular lesions or benign lymphangiomatous papules.

METHODS

The objective of this study was to investigate the clinicopathologic features and outcomes of 56 radiation-induced vascular proliferations that occurred in 36 patients who received previous treatment for breast carcinoma. Data from all patients were retrieved from the files of the French Sarcoma Group. Immunostaining with D2.40 antibody was performed in 24 lesions.

RESULTS

All patients (median age, 52 years) had received external radiotherapy. Small papules developed within the field of prior radiotherapy (median latency interval, 66 months). Microscopically, the lesions were relatively well circumscribed, and they were located mostly in the superficial/middermis. They were composed of dilated or irregular-jagged vascular channels that were lined by a single layer of bland endothelial cells, and they demonstrated either a predominately lymphangioendothelioma-like or lymphangioma/lymphangioma circumscriptum-like growth pattern. Micropapillary tufts were common findings. Ten lesions showed additional cytologic and/or architectural atypia. Twenty of 24 lesions showed D2.40 positivity. Follow-up information was available for 31 patients (median follow-up, 48 months): Five women developed new cutaneous lesions, and 1 woman had spontaneous regression of her lesions. None of the patients developed cutaneous angiosarcoma. Five patients were lost to follow-up.

CONCLUSIONS

Although vascular proliferations in irradiated skin may mimic angiosarcoma morphologically, the large majority of these lesions showed a benign clinical outcome. Despite relatively limited follow-up, the current results indicate the benign nature of these vascular proliferations.

Vascular low-flow malformations in children: current concepts for classification, diagnosis and therapy

Congenital vascular malformations (CVM) are made of dysplastic vessels with no cellular proliferation. Low- or slow-flow malformations (LFM) consist predominantly of venous and/or lymphatic vessels. Correct terminology is necessary for differentiating vascular malformations from tumours such as haemangiomas, in order to prevent ineffective or even adverse therapy. The role of the radiologist in the management of patients is two-fold: making the diagnosis with the use of ultrasound and magnetic resonance imaging, and performing sclerotherapy, which is the treatment of choice. Prior to sclerotherapy, percutaneous phlebography is necessary to visualize the dynamic situation inside the lesion and the flow into the adjacent vascular system. The double-needle technique is a useful therapy option reducing the risk of embolisation of the sclerosing agent. Large lesions might need subsequent surgical treatment. A multidisciplinary approach is substantial for optimal patient management.

[Risk factors for lymphatic metastasis from pT1 colorectal adenocarcinoma]

During the last 20 years, endoscopic removal of colorectal adenoma has become widely accepted as a replacement for removal by open surgery. Even colorectal adenocarcinomas are not excluded. The key question is when surgical treatment should still be preferred over endoscopic removal as the primary treatment. One good indicator is the frequency of lymph node metastasis, which should be compared with the overall risk involved in the surgical procedure itself. Histological examination allows subdivision of early colorectal adenocarcinomas into low-risk and high-risk groups. Classical parameters for a high-risk situation are lymphatic invasion, poor differentiation, and incomplete removal (R1). Additional risk factors that have recently been discussed are infiltration into the lower third of the submucosal layer (sm3) and dissociation (budding) of the tumour cells at the invasion front. Drawing on the literature and an analysis of our own patients, we demonstrate a positive correlation between these new markers and an elevated risk of the presence of lymph node metastasis.