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Cystic lymphangiomas of the adrenal gland are rare. A 79-year-old female presented in the emergency room with epigastric discomfort, and an immovable mass was palpated in her abdomen upon physical examination. Imaging studies revealed a large cystic lesion in the pancreatic tail. The radiologic impression ruled out the possibility of a mucinous cystic neoplasm, or a pseudocyst in the pancreas. The operative findings demonstrated that the cystic mass originated in the left adrenal gland. A laparoscopic excision of the cystic mass was performed, and immunohistochemistry confirmed that this mass was a lymphangioma of the adrenal gland. Several prior reports have suggested that lymphangioma can mimic renal or splenic cysts. However, lymphangioma cases mimicking pancreatic cysts are very rare.

Vascular lesions are commonly encountered in routine pathologic practice and often pose diagnostic challenges owing to their morphologic diversity. Although WT-1 expression was reported in some vascular tumors, little is known about its staining patterns in a spectrum of vascular lesions from various locations. We examined WT-1 immunostain in 95 cases of vascular lesions including angiosarcomas (AS, 19 cases), hemangioendotheliomas (HE, 5), Kaposi's sarcomas (KS, 4), cavernous hemangiomas (CVH, 12), capillary hemangiomas (CPH, 7), pyogenic granulomas (PG, 4), lymphangiomas (LA, 4), hemangiopericytomas (HP, 5), glomus tumors (GT, 8), vascular malformation (VM, 13) and granulation tissue (GRT, 14). Strong WT-1 cytoplasmic stain was invariably observed in all cases of malignant and borderline vascular tumors including AS (19/19), KS (4/4) and HE (5/5). WT-1 was also consistently expressed in CPH (7/7), PG (4/4), and GRT (14/14), while it became weaker in VM (10/13) and often negative in CVH (2/12) and LA (0/4). WT1 stain was not demonstrated in HP (0/5) and rarely in GT (2/8). We conclude that consistent and diffuse WT-1 cytoplasmic stain in AS, HE and KS can be useful in distinguishing these tumors from poorly differentiated tumors with mimicking features. On the other hand, reliable WT-1 stain in CPH, PG and GRT may help in differential diagnosis with non-endothelial vascular tumors such as GT and HP. Recognizing the WT-1 cytoplasmic stain in a broad spectrum of benign and neoplastic tissues is critical in formulating appropriate immunohistochemical panels and avoiding misinterpretation of results.

Papillary intralymphatic angioendothelioma (PILA) or Dabska tumor is extremely rare, and often affects the skin and subcutaneous tissues of children. Since its first description by Dabska, only a few intraosseous cases have been described in the literature and none of them presents with multifocal osteolytic lesion of bones. We present a case of unusual multifocal intraosseous PILA in facial bones occurring in a 1 year 3 month old male child. Computed tomography (CT) scan revealed multifocal osteolytic lesions were located at the left zygoma, left orbital bone and right maxillary. Histologically, the lesions were ill-defined and composed of multiple delicate interconnecting vascular channels with papillae formation which projected into the lumen lined by atypical plumped endothelial cells. The vascular channels were also lined by plump cuboidal endothelial cells with focal hobnailed or "match-head" appearance. In some areas, endothelial cells formed solid-appearing aggregates with vessel lumens. By immunohistochemistry, the tumor cells were positive for CD31, CD34 and D2-40 at varying intensity. A final diagnosis of intraosseous PILA was made. To the best of our knowledge, this case is the first case of primary multifocal osseous PILA., Virtual Slides: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1919488629100787.

A 52-year-old woman presented with upper abdominal pain. Abdominal ultrasonography showed a 4-cm well-defined mass containing solid and cystic components in segment IV of the liver, and contrast-enhanced T1-weighted magnetic resonance imaging revealed heterogeneous enhancement within the tumor, indicating a solid or fibrous component. There were no cystic lesions in any other organs. A partial hepatectomy was performed, based on a preoperative diagnosis of sclerosing hemangioma and biliary cystadenoma or cystadenocarcinoma. Pathologically, the tumor appeared to be a multilocular and cystic lesion lined by attenuated endothelial- like cells with no atypia. Immunohistochemistry demonstrated the endothelial-like cells to be positive for the lymphatic-specific markers D2-40, LYVE-1, and Prox-1, which proved helpful for confirming the diagnosis as solitary hepatic lymphangioma. This case is presented with details of the pathologic and radiologic findings, because solitary hepatic lymphangioma is an extremely rare tumor and no previous reports have provided details of the immunohistochemical characteristics.

Blue Rubber Bleb Nevus Syndrome is a rare, primarily sporadic condition characterized by vascular lesions principally involving the skin and gastrointestinal tract. Although considered a venous malformation, telangiectatic capillaries, arteriovenous malformations, and lymphangiomas have been reported, but a lymphangiomatosis-like growth pattern has not been described. This case of Blue Rubber Bleb Nevus Syndrome demonstrated a labyrinth of variably sized vascular spaces lined by an attenuated layer of bland endothelial cells, dissecting uterine tissues and sequestering remaining myometrium. Immunohistochemical profile of lesional endothelial cells from the myometrium included strong, diffuse CD31; variable CD34; strong, patchy D2-40; weak, patchy factor VIII-related antigen; focal linear subendothelial collagen type IV; Ki-67 in 1% of cells; and no GLUT-1 or WT1 expression. This report expands the morphological spectrum of vascular lesions in Blue Rubber Bleb Nevus Syndrome to include a lymphangiomatosis-like growth pattern and the immunohistochemistry suggests dual vascular and lymphatic differentiation, supporting the current belief that these lesions are malformations.

Mediastinal lymphangiomatosis in a 70-year-old woman was diagnosed on a medical checkup. The tumor was resistant to sclerotherapy with OK432 or bleomycin. The patient continued on a downhill course and died approximately 3 years after the initial diagnosis. Autopsy revealed a large tumor mass occupying the anterior mediastinum and firmly adhered to the pericardium and the pleura. The tumor consisted of two intermingled lesions: dilated vessels lined with D2-40-positive lymphatic endothelium and CD5-positive atypical cell nests with focal keratinization. The former was diagnosed as lymphangiomatosis and the latter as thymic squamous cell carcinoma. Vascular endothelial growth factor (VEGF)-C, a growth factor for lymphatic endothelial cells, was expressed by the carcinoma, and VEGF-C receptor was expressed by the endothelium of lymphangiomatosis. These findings suggested that VEGF-C derived from the thymic carcinoma induced the lymphangiomatosis lesion in a paracrine manner.

Background: Lymphangioma-like Kaposi's sarcoma (LLKS) is a rare morphologic expression of Kaposi's sarcoma (KS) that occurs in virtually all of the well-recognized clinical subtypes of the disease and has the potential to mimic other pathologic processes. In this study, we present the clinical and pathological features of four patients with LLKS., Methods: Four cases of LLKS were retrieved from the dermatopathology files of our institution. All four tumours were tested immunohistochemically with anti-human herpesvirus-8 (HHV-8) latent nuclear antigen-1 (LNA-1) and anti-CD34 antibodies., Results: Clinically, each patient presented with violaceous patches, papules or plaques; one patient presented with bullous lesions. All of the LLKS biopsy specimens revealed areas with characteristic light microscopic features of KS. Lymphangioma-like foci consisted of ectatic, irregularly shaped vascular spaces lined by mildly atypical endothelial cells. All tumour cells, including those associated with LLKS foci, showed a strong and diffuse reactivity for anti-HHV-8 LNA-1 and anti-CD34. KS progressed slowly in two patients with adequate follow-up., Conclusions: As LLKS can mimic other disease processes, the correct diagnosis relies heavily on the recognition of salient clinical and histological features of conventional KS, including a strong immunohistochemical expression of HHV-8-associated LNA-1 in lesional cells.

Cytological diagnosis of adrenal cysts is becoming more important, with the increase in cases identified due to the widespread use of imaging modalities. Adrenal cysts have been classified into four main groups: endothelial, epithelial, parasitic, and pseudocyst, with endothelial cysts further classified as lymphangiomatous or angiomatous. We report on a case of adrenal lymphangioma with atypical lymphocytes found in the intraoperative aspirate, suggesting an inconclusive diagnosis, although immunohistochemical study led us to suppose their B-cell origin. This case provided important cytological findings that may assist in the prevention of cytological overdiagnosis., (Copyright 2003 Wiley-Liss, Inc.)

A 76-year-old man complained of difficulty breathing. A solitary mass was found in the spleen by ultrasonography and the tumor was excised. Grossly, the tumor was 3.9 x 2.9 cm in size, solid and brownish in color. A stellate scar-like fibrosis was observed in the center of the tumor. Histologically, the tumor consisted of the proliferation of irregular and small lymph vessel-like spaces, with sclerotic change in the center. The lymph vessel-like spaces showed papillary projections of the lining cells. The lumen contained amorphous proteinaceous fluid. Immunohistochemically, the lining cells of lymph vessel-like spaces were positive for endothelial markers (CD31, CD34, factor VIII-related antigen), and bound Ulex europaeus agglutinin-1. The tumor was diagnosed as splenic lymphangioma, but its appearance was rather unusual for a typical splenic lymphangioma because of the presence of papillary endothelial proliferation and scar-like fibrosis. Splenic lymphangioma with papillary endothelial proliferation is uncommon, and there have been only four cases reported.

Detection of lymphatic endothelal cells (LECs) has been problematic because of the lack of specific markers. The homeobox transcription factor Prox1 is expressed in LECs of murine and avian embryos. We have studied expression of Prox1 in human tissues with immunofluorescence. In 19-wk-old human fetuses, Prox1 and vascular endothelial growth factor receptor-3 (VEGFR-3) are coexpressed in LECs of lymphatic trunks and lymphatic capillaries. Prox1 is located in the nucleus, and its expression is mutually exclusive with that of the blood vascular marker PAL-E. Prox1 is a constitutive marker of LECs and is found in tissues of healthy adults and lymphedema patients. Blood vascular endothelial cells (BECs) of hemangiomas express CD31 and CD34, but not Prox1. A subset of these cells is positive for VEGFR-3. Lymphatics in the periphery of hemangiomas express Prox1 and CD31, but not CD34. In lymphangiomas, LECs express Prox1, CD31, and VEGFR-3, but rarely CD34. In the stroma, spindle-shaped CD34-positive cells are present. We show that Prox1 is a reliable marker for LECs in normal and pathologic human tissues, coexpressed with VEGFR-3 and CD31. VEGFR-3 and CD34 are less reliable markers for LECs and BECs, respectively, because exceptions from their normal expression patterns are found in pathologic tissues.

Background: Existence of true orbital lymphangiomas has been questioned in recent years. Therefore an orbital lymphangioma was analyzed with two new specific markers of lymphatic endothelium., Methods: Case-report with clinicopathological, immunohistochemical, and ultrastructural findings. A 25-year-old man presented with recurrent lower lid "hematomas" and a pea-sized tumor palpable in the left lower lid. Magnetic resonance imaging showed an inferonasally located orbital tumor which extended to the posterior pole of the eye. The highly vascularized tumor was excised by medial orbitotomy., Results: Histopathologically, the mass consisted of large, erythrocyte-filled cavernous vessels without evidence of smooth muscle cells or pericytes surrounding them. Numerous lymph follicles and small arterioles were scattered between them. Immunohistochemically, endothelial cells lining the lumina of the cavernous vessels were partly positive for podoplanin and vascular endothelial growth factor receptor 3 (flt-4), two markers of lymphatic endothelium. These markers did not react with endothelial cells lining the arterioles. Ultrastructurally, cavernous vessels displayed features characteristic of lymphatic vessels, and the smaller vessels demonstrated signs of arterioles., Conclusion: Ultrastructural analysis and immunohistochemistry using two new markers of lymphatic endothelium suggest a lymphatic nature of large vessels in an orbital lymphangioma. A greater series of vascular orbital tumors must be studied with these new lymph endothelial markers to confirm the existence of true orbital lymphangiomas and to analyze different profiles of lymph endothelial marker expression.

Primary angiosarcoma of the spleen is a rare neoplasm that has not been well characterized. We describe the clinical, morphologic, and immunophenotypic findings of 28 cases of primary splenic angiosarcoma, including one case that shares features of lymphangioma/lymphangiosarcoma. The patients included 16 men and 12 women, aged 29 to 85 years, with a mean of 59 years and median of 63 years. The majority of patients (75%) complained of abdominal pain, and 25% presented with splenic rupture. The most common physical finding was splenomegaly (71%). Seventeen of 21 patients were reported to have anemia. Macroscopic examination showed splenomegaly in 85% cases. Sectioning revealed discrete lesions in 88% of cases, ranging from well-circumscribed firm nodules to poorly delineated foci of necrosis and hemorrhage associated with cystic spaces. Microscopically, the tumors were heterogenous; however, all cases demonstrated at least a focal vasoformative component lined by atypical endothelial cells. Solid sarcomatous, papillary, and epithelioid growth patterns were observed. The solid sarcomatous component resembled fibrosarcoma in two cases and malignant fibroushistiocytoma in one case. Hemorrhage, necrosis, hemosiderin, extramedullary hematopoiesis, and intracytoplasmic hyaline globules were frequently identified. A panel of immunohistochemical studies revealed that the majority of tumors were immunoreactive for at least two markers of vascular differentiation (CD34, FVIIIRAg, VEGFR3, and CD31) and at least one marker of histiocytic differentiation (CD68 and/or lysozyme). Metastases developed in 100% of patients during the course of their disease. Twenty-six patients died of disease despite aggressive therapy, whereas only two patients are alive at last follow-up, one with disease at 8 years and the other without disease at 10 years. In conclusion, primary splenic angiosarcoma is an extremely aggressive neoplasm that is almost universally fatal. The majority of splenic angiosarcomas coexpress histiocytic and endothelial markers by immunohistochemical analysis, which suggest that some tumors may originate from splenic lining cells.

Benign lymphangioendothelioma (BL) is a rare vascular neoplasm that can histopathologically mimic a low-grade angiosarcoma or the patch stage of Kaposi sarcoma. We report on the case of a 49-year-old man with a benign lymphangioendothelioma on the right thigh that evolved on a vascular birthmark after a trauma. Because of constant pain and the slow but progressive growth of the lesion, we decided to excise the tumor. Three stages of surgery were needed to obtain negative margins. We review the reports of BL to date, with special attention to those that developed after trauma and those that had a preexistent vascular lesion, and expound on the histopathologic differential diagnosis with low-grade angiosarcoma.

Lymphangiomas of the ovary are rare tumors, with only 13 cases reported. The diagnoses of these tumors have been based on histologic findings without immunohistochemical confirmation of endothelial cell origin. It is uncertain if these tumors are true neoplasms or if some represent reactive lesions. In this report, the literature is reviewed, and a 53-year-old woman with bilateral ovarian lymphangiomas is described. The ovarian masses were composed of numerous, thin-walled, cystic spaces containing a proteinaceous fluid, mature lymphocytes, and occasional erythrocytes. The cyst walls were lined by flat, benign-appearing cells that were immunoreactive for factor VIII-related antigen, CD34, and CD31. Further examination of the specimen showed absent fallopian tube fimbriae, tuboovarian adhesions, and chronic follicular salpingitis, suggesting that the lymphatic proliferation in the ovaries was a reactive change secondary to impaired regional lymphatic drainage.

Background: Pancreatic lymphangiomas are rare benign tumors, of which only a few cases have been reported in the literature. In this study, the authors present a series of primary pancreatic lymphangiomas., Methods: Cases of nonepithelial pancreatic cystic tumors (lymphangiomas) diagnosed between 1966 and 1994 were retrieved from the Endocrine Pathology Registry of the Armed Forces Institute of Pathology. Histologic features (in 10 cases) as well as histochemical and immunohistochemical studies (in 6 cases) were reviewed. Long term patient follow-up data were obtained in 9 cases., Results: The patients included 8 females and 2 males ages 2-61 years (mean age, 28.9 years) at initial presentation. The tumors were circumscribed and occurred predominantly (in 6 of 10 cases) in the tail of the pancreas. The multicystic, serous, or chylous fluid-filled cystic tumors ranged from 3 to 20 cm (average, 12.7 cm) in greatest dimension. Histologically, the tumors consisted of multilocular cystic spaces of various sizes, lined by endothelial cells. The stroma contained smooth muscle and mature lymphocytes. Immunohistochemistry determined the endothelial lining cells to be factor VIII-R antigen and CD31 positive (in all cases tested) but usually CD34 negative. All patients for whom follow-up data were obtained (n=9) were alive without evidence of disease an average of 7.2 years after initial diagnosis., Conclusions: Pancreatic lymphangiomas occur predominantly in females within a wide age range. Multilocular, fluid-filled cysts, with endothelial immunoreactivity for factor VIII-R antigen and CD31, are characteristic of these tumors. Complete surgical excision of these benign tumors resulted in excellent long term prognoses for all patients studied.

We report a rare case of epithelioid leiomyoma of the uterus presenting as a multilocular cystic mass containing clear fluid. The histologic basis of cysts was the diffuse intratumoral cystic degeneration. Histologically, the presence of numerous cystic cavities of variable size raised the possibility that vascular abnormalities, such as hemangioma, lymphangioma, and diffuse cavernous angiomatosis, could be associated with epithelioid leiomyoma. An immunohistochemical study using endothelial cell and basement membrane markers, was helpful in excluding the vascular nature of the cystic cavities and revealed an unexpected focal lymphangioma-like pattern as a peculiar component of tumor.

Objective: Intra-abdominal lymphangiomas are rare in children and even more exceptional in adults. Because these lesions occasionally progressively enlarge, we analyzed seven adult and four pediatric cases for evidence of proliferative activity., Design: Immunohistochemical analysis was performed retrospectively on representative tissue sections using antibodies to the following antigens: Ki-67, proliferating cell nuclear antigen, and p53 gene product (eight cases). DNA ploidy was examined in five cases., Patients: The study group consisted of seven adult women (aged 24 to 73 years), a 3.5-year-old girl, and two boys, aged 3.5 and 9 years, the last with a recurrence at age 15. The lymphangiomas ranged from 1.7 to 23 cm in maximum size., Results: Ranges of percentages of cells staining for proliferating cell nuclear antigen, Ki-67, and p53 were similar between the pediatric and adult cases. Antibody to Ki-67 stained from 0.5% to 17% of the stromal and endothelial components of the lymphangiomas. Proliferating cell nuclear antigen activity was noted in 16% to 52% of lesional cells. Reactivity was noted almost exclusively in areas of inflammation and fibroplasia. For comparison, 10% to 50% of intermixed lymphocytes stained for Ki-67 and proliferating cell nuclear antigen. There was no labeling with p53. DNA content was uniformly diploid., Conclusions: The scant staining for Ki-67 in the majority of the lesions, combined with proliferative rates that were only focally elevated, suggests that lymphangiomas in children and adults are quiescent lesions whose enlargement is due to engorgement by chyle and localized secondary inflammation rather than primary tumoral growth.

Lymphangiomas of the spleen may occur as part of lymphangiomatosis or may represent solitary lesions. Solitary splenic lymphangiomas are described traditionally as subcapsular, multicystic proliferations that are often incidental findings. Six cases of splenic tumors with morphologic features similar to those described for solitary lymphangioma were studied using an immunohistochemical panel that included epithelial and vascular markers. None of the patients had evidence of lymphangiomatosis, and all tumors were incidental findings in splenectomy specimens. All cases demonstrated lining cells that were positive for keratin and the mesothelial cell-associated antibody HBME-1 but were negative for the vascular markers Factor VIII-related antigens, CD31, and CD34. The immunohistochemical findings are suggestive of a mesothelial derivation of these multicystic proliferations rather than representing true lymphangiomas.

Six cases of a distinctive but poorly recognized variant of lymphangiomatosis with predominant or exclusive involvement of the soft tissues of the limb/limb girdle are described. The six patients were male and presented with slowly progressive swelling of the involved limb. The age of onset was at birth (three cases), 3 months (one case), 11 years (one case) and 12 years (one case). Five patients had involvement of the lower extremity and one of the right upper extremity. Three patients had concomitant asymptomatic bone involvement either in the affected limb (two cases) or in distant bones (one case). Only one patient had visceral involvement that was limited to the ipsilateral thorax and was associated with chylothorax. Diagnosis was confirmed in all but one patient by lymphangiography. Treatment consisted principally of surgical reduction with significant clinical improvement. No patient later developed systemic involvement and the clinical course was benign. The bone lesions did not progress in any patient. Histologically, each case was characterised by interconnecting, dilated lymphatic spaces, lined by a single, attenuated layer of endothelial cells, involving the dermis, subcutis, and occasionally, underlying fascia and skeletal muscle with characteristic and extensive "dissection" of collagen and surrounding normal adnexal structures. Despite the absence of red blood cells in the vascular spaces, interstitial hemosiderin deposition was prominent in four cases. As opposed to most cases of lymphangiomatosis, which usually have extensive visceral involvement associated with a very poor prognosis, involvement in this variant is limited almost exclusively to soft tissues of the limb and bone and is associated with good prognosis.

Angiomatous lesions of the lung are uncommon and not well characterized. We describe nine cases of a distinct lymphatic vascular lesion that we have termed "diffuse pulmonary lymphangiomatosis." Extrathoracic lymphangiomatous lesions were not identified. The patients comprised seven males and two females with a mean age at presentation of 10 years (age range, 1 month to 33 years). Six patients were younger than 10 years of age. Symptoms included "wheezing" or "asthma" (44%) and dyspnea (22%) present for 3 months to 20 years. Chest radiographs showed bilateral interstitial infiltrates, often greatest in the lower lobes. Pleural or pericardial effusions were present or developed in six patients. Pulmonary function tests showed in two patients and mixed obstruction and restriction in five patients. Open lung biopsies (nine patients) and autopsy (one patient) showed anastomosing endothelial lined spaces along pulmonary lymphatic routes (especially pleural and interlobular septal) accompanied by asymmetrically spaced bundles of spindle cells, which were prominent in six cases. Hemosiderin deposition often was present in the spindle cell areas and in the adjacent lung. The lining cells were positive for factor VIII-related antigen (eight cases) and Ulex europaeus I agglutinin (four cases). The spindle cells were reactive with antibodies to vimentin (nine cases), desmin (six cases), actin (seven cases), progesterone receptor (seven cases), and proliferating cell nuclear antigen (one case); they were negative for estrogen receptor (seven cases), keratin, (eight cases), and HMB-45 (eight cases). Diffuse pulmonary lymphangiomatosis was progressive in eight cases and was most aggressive in the youngest children. Two of the children have died, one of pulmonary hemorrhage and the other after heart-lung transplantation. Diffuse pulmonary lymphangiomatosis is distinct from lymphangiectasis, lymphangioleiomyomatosis, pulmonary capillary hemangiomatosis, Kaposi's sarcoma, and kaposiform hemangioendothelioma. Due to its distribution and histology, a lymphatic origin of the lesion is favored.

We present a 27-year-old woman with non-systemic diffuse lymphangiomatosis of spleen and liver. The tumour consisted of capillary and cavernous lymphatic vessels located in abundant fibrous tissue. The vascular endothelium showed immunoreactivity for factor VIII-related antigen. A basal lamina could be demonstrated immunohistochemically and by electronmicroscopy.

Acquired progressive lymphangioma is rare and can histologically mimic well-differentiated angioendothelioma. In a 9-year-old boy with acquired progressive lymphangioma, we demonstrated that the neoplasm consists of at least a vascular component and a smooth muscle component. The presence of type IV collagen around many vascular channels suggests that an intermediate stage of differentiation between blood vessels and lymphatics may be present. Our findings indicate that acquired progressive lymphangioma is most likely a complex hamartoma composed of vascular channels and smooth muscle.

In the present report we analyzed the presence and distribution of various basement membrane (BM) proteins in normal blood and lymph vessels with special emphasis on BM-associated heparan sulfate proteoglycan (HSPG) when compared to the BM-components collagen IV, laminin and fibronectin. We found that normal lymph capillaries have a BM that contains only collagen IV and small amounts of laminin, but almost no BM-associated HSPG and fibronectin, while blood capillaries showed a BM comprising of all components tested for. Larger lymphatics, however, were indistinguishable from blood vessels on the basis of BM staining. Lymphangiomas showed a BM pattern similar to that of lymph capillaries. Our findings provide evidence that the differential staining of BM-components may represent a reliable method for morphological distinction between blood and lymph capillaries. A comparison of these results with the BM-pattern in other functionally specialized blood vessels (glomerulus, sinusoids) provides evidence that the BM-composition may have some major impact on the functional properties. Thus, it is conceivable that the lack of HSPG in lymph capillaries may be essential for a free influx of fluid and proteins into these capillaries, which may have been extravasated into the interstitium.

Cystic hygromas are large lymphangiomas that are most often found in the posterior triangle of the neck and the axilla in children. They are most frequently found before age 2 and may be massive. After upper respiratory infection, they may become infected and enlarged, causing dysphagia and toxemia. The diagnosis can usually be made by history and physical examination and confirmed by biopsy. Treatment is by surgical excision of small lesions and staged debulking excisions in more severe cases. A patient with a cystic hygroma having many clinical characteristics of a plunging ranula is presented. The cyst fluid was aspirated and analyzed for its amylase, sodium, potassium, chloride, urea nitrogen, glucose, and total protein content. The characteristics of the fluid were also compared with those of lymph and saliva. This report demonstrates the difficulty in determining the diagnosis of a tumor that has the clinical features of a cystic hygroma, as well as a plunging ranula. The necessity of a proper presurgical diagnosis is essential since the form of therapy for each is different and conflicting. A method that distinguishes between the cervical cystic hygroma and a plunging ranula by means of aspirated fluid is discussed.

In this study we have compared the light microscopical, immunohistochemical, and ultrastructural features of five hemangiomata of the dermis with five lymphangiomata of the dermis and subcutaneous tissue. We have attempted to define differentiating features with regard to the ultrastructural appearances and the immunohistochemical staining for the endothelial markers factor VIII-related antigen (FVIII:RAg) and Ulex europaeus agglutinin I (UEA-I). In addition, immunolocalization of FVIII:RAg at the ultrastructural level was performed to compare its distribution within endothelial cells of neoplastic blood vessels and lymphatic vessels. The results show that immunohistochemical staining for FVIII:RAg and UEA-I does not differentiate between blood and lymphatic vessels. However, the presence of a fragmented basal lamina and anchoring filaments does distinguish lymphatic vessels from blood vessels ultrastructurally.

We studied dendritic cells in the dermis of six angiofibromas by the peroxidase-antiperoxidase method in order to determine whether they are endothelial cells. The primary antiserum used was directed to factor VIII, an endothelial cell marker. The dendritic cells were not immunoreactive for factor VIII, suggesting that they are not endothelial cells.