Pseudopyogenic granuloma: enzyme histochemical and ultrastructural study

Angiolymphoid Hyperplasia with Eosinophilia and Radial Artery Pseudoaneurysm

A case of angiolymphoid hyperplasia with eosinophilia arising from the radial artery is presented. Histologically, there was proliferation of atypical endothelial cells forming vascular spaces and solid cords, with a background infiltrate of inflammatory cells and prominent tissue eosinophilia. Immunohistochemical studies demonstrated vimentin and Factor VIII-related antigen in the endothelial cells. The lymphoid infiltrate was polyclonal. The authors discuss the probable nature of this process, which typically occurs in the dermis and subcutaneous tissue of the head and neck and is known by a variety of different names, reflecting disagreement regarding pathogenesis. This case draws attention to the fact that it can arise not only within the dermis and subcutaneous tissue of the head and neck, but also from major peripheral arteries. Angiolymphoid hyperplasia with eosinophilia should be considered promptly in the doubtful case of a pulsatile mass arising from peripheral arteries as it may lead to an earlier diagnosis and timely treatment with lower morbidity.

Epidemiology and treatment of angiolymphoid hyperplasia with eosinophilia (ALHE): A systematic review

BACKGROUND

Current knowledge of angiolymphoid hyperplasia with eosinophilia (ALHE) derives from retrospective reports and case series, leading to a nonevidence-based treatment approach.

OBJECTIVE

We sought to systematically review the literature relating to cutaneous ALHE to estimate its epidemiology and treatment outcomes.

METHODS

A literature search of PubMed, EMBASE, Web of Science, and Google Scholar was conducted. Articles detailing cases of histologically confirmed cutaneous ALHE were included.

RESULTS

In all, 416 studies were included in the review, representing 908 patients. There was no sex predominance among patients with ALHE. Mean age at presentation was 37.6 years. There was a significant association between presence of multiple lesions and pruritus, along with bleeding. Surgical excision was the most commonly reported treatment for ALHE. Treatment failure was lowest for excision and pulsed dye laser. Mean disease-free survival after excision was 4.2 years. There were higher rates of recurrence postexcision with earlier age of onset, longer duration of disease, multiple lesions, bilateral lesions, pruritus, pain, and bleeding.

LIMITATIONS

Potential for publication bias is a limitation.

CONCLUSIONS

Surgical excision appears to be the most effective treatment for ALHE, albeit suboptimal. Pulsed dye and other lasers may be effective treatment options. More studies are needed to improve the treatment of ALHE.

Angiolymphoid Hyperplasia with Eosinophilia of the Orbit and Adnexa

PURPOSE

Angiolymphoid hyperplasia with eosinophilia (ALHE) is a rare disorder presenting with solitary or multiple nodules in the dermis or subcutaneous tissues. ALHE shares clinical as well as histopathological characteristics with Kimura disease (KD), but they have been considered to be two distinct entities based on their histological features. Orbital and adnexal involvement in ALHE is rare. The published literature is limited to few case reports featuring single cases.

METHODS

We report a series of 5 cases of ALHE presenting with diverse clinical features seen at a tertiary referral care centre in India. We also review the published literature with a special emphasis on the treatment modalities for orbital and adnexal ALHE.

RESULTS

Three patients of this series presented with orbital involvement, while the remaining 2 had involvement of the eyelid. Three patients underwent incisional and/or excisional biopsy, whereas 2 were managed conservatively. There were no recurrences seen on follow-up.

CONCLUSIONS

ALHE can rarely involve the orbit and adnexa. There is no consensus on the best modality of management of this rare entity. ALHE and KD have often been considered variations of the same disease, but it is important to differentiate between the two entities for optimal patient management.

PSEUDOPYOGENIC GRANULOMA

Papular lesions of pseudopyogenic granuloma were examined before and during treatment with systemic corticosteroid using both light and electron microscopy. Before treatment, these lesions showed a proliferation of vessels lined with plump endothelial cells and heavy lymphohistiocytic infiltrates with numerous eosinophils in the dermis. During treatment, flattened papules showed a dilatation of vessels lined with flattened endothelial cells, extravasation of red cells, discontinuity of endothelial basal lamina, and, ultimately, discontinuity of the endothelial cells themselves. Eosinophils were rarely found. From these findings, it can be said that the morphological effects of corticosteroid on microvasculature have in part been elucidated.

Angiolymphoid Hyperplasia with Eosinophilia in Association with a Vascular Malformation

A unique case is presented in which a lesion of angiolymphoid hyperplasia occurs in association with a vascular malformation. The skin and the intravascular lesion showed, on microscopic examination, angiolymphoid hyperplasia, which to my understanding, is a reactive process. The nodule represents, in my view, satellite lesions of the A-V malformation--in other words a skin manifestation of the intravascular process. The same phenomenon has been reported in some pyogenic granulomas and hemangiomas.

Epithelioid Lesions

Epithelioid variants have been described for most mesenchymal tumors, including leiomyosarcoma, pleomorphic liposarcoma, epithelioid fibrous histiocytoma, and myxofibrosarcoma. Soft tissue tumors that commonly show epithelioid morphology include epithelioid vascular lesions, epithelioid sarcoma, sclerosing epithelioid fibrosarcoma, and epithelioid malignant peripheral nerve sheath tumor. Many of the entities described in this review were originally described as "simulating carcinoma" or "often mistaken for carcinoma" and this pitfall should be considered when evaluating epithelioid lesions in soft tissue. Many epithelioid soft tissue tumors express epithelial antigens to a varying degree and an immunohistochemical panel is essential for correct classification.

Epithelioid hemangioma of the penis: a clinicopathologic and immunohistochemical analysis of 19 cases, with special reference to exuberant examples often confused with epithelioid hemangioendothelioma and epithelioid angiosarcoma

Epithelioid hemangiomas of the penis are very rare. To date, less than 10 examples have been reported in the English language literature. In this report, we describe the clinical, histopathologic, and immunohistochemical findings in 19 cases retrieved from our files. The patients ranged in age from 23 to 75 years (median age, 45 years) at the time of initial surgical resection. Seventeen patients presented with a solitary mass, and two presented with two separate, but closely approximated, lesions. The process involved the glans penis (n = 3), shaft (n = 11), base of the penis (n = 2), or penis, not otherwise specified (n = 3). The lesions ranged in size from <0.5 to 2.5 cm (median size, approximately 1.2 cm) in greatest dimension. Eleven examples were specifically noted to be dorsally located, and only one was stated to be ventral. Localized pain or tenderness was the most common complaint, documented in 12 cases. The preoperative duration of the lesions ranged from 5 days to 1 year (median 4.5 months). Microscopically, all examples contained a tumefactive proliferation of epithelioid endothelial cells, often in a nodular or lobular configuration and associated with an inflammatory infiltrate containing lymphocytes and eosinophils. In 14 cases, the vascular proliferation was associated with a small arterial segment, sometimes with mural damage and frequently (n = 13) with intraluminal epithelioid endothelial cells. Based on the growth pattern of the epithelioid endothelial cells, 13 cases were considered "typical," and six were considered exuberant or "atypical." The latter examples had a prominent centrally located zone where nests or sheet-like aggregates of epithelioid endothelial cells did not form discrete vessels. Immunohistochemical data are available for 15 tumors. The epithelioid endothelial cells usually had strong reactivity for CD31, lesser reactivity for factor VIIIrAg, and minimal reactivity for CD34. In 9 of 12 cases, a small number of epithelioid endothelial cells expressed keratins. In all cases tested, at least focal muscle-specific actin-positive myopericytic cells were present bordering the endothelial cells, and this was especially notable peripherally. Initial surgical intervention consisted of either a shave biopsy (n = 1), excisional biopsy (n = 2), or local excision (n = 16). A complete follow-up history is available for 12 patients, and incomplete follow-up information is available for an additional four patients. One patient developed a new epithelioid hemangioma at a site within the penis separate from the initial lesion, but no patient is known to have experienced a true metastasis or to have died of complications of this process. Optimal management appears to be complete local excision with periodic follow-up visits to monitor for local recurrence.

Angiolymphoid hyperplasia with eosinophilia (epithelioid hemangioma) of the breast: report of a case

We report herein the unusual case of a 35-year-old woman found to have angiolymphoid hyperplasia with eosinophilia (ALHE) of the breast. The patient was initially referred to our hospital for investigation of a well-circumscribed breast lump, 2.5 cm in diameter, and a clinical diagnosis of fibroadenoma was made. However, fine-needle aspiration cytology of the lump revealed an admixture of lymphocytes and eosinophils. Therefore, the lump was excised and microscopic examination showed features of ALHE. No evidence of recurrence of the lump has been seen in the 2 years since this excision. To the best of our knowledge, this is the first case to be documented of ALHE arising in the breast.

Angiolymphoid hyperplasia with eosinophilia successfully treated with a long-pulsed tunable dye laser

BACKGROUND

To date, both surgical excision and laser treatments for angiolymphoid hyperplasia with eosinophilia (ALHE) have resulted in scarring.

OBJECTIVE

Based on the principle of selective photothermolysis, we considered employing the newer long-pulsed tunable dye laser in the treatment of ALHE, as less scarring would be expected and deeper blood vessels could be ablated.

METHODS

After punch biopsy specimens confirmed the diagnosis, the patient was treated on two separate occasions, 2 months apart with a long-pulsed tunable dye laser.

RESULTS

The lesions flattened after the initial treatment and resolved after a second treatment. No scarring was detectable and no recurrence was noted in follow-up after 1 year.

CONCLUSION

We conclude that the long-pulsed tunable dye laser can be employed successfully to treat superficial lesions of ALHE, particularly in cosmetically sensitive areas.

Kimura disease of the orbit and ocular adnexa

Kimura disease (KD) is a distinct clinicopathologic entity that has been the subject of considerable confusion and debate. Although common in Asia, KD rarely occurs in non-Asian patients. Kimura disease shares both clinical and histopathologic features with angiolymphoid hyperplasia with eosinophilia (ALHE). Because of this overlap and the rarity of KD in Europe and the United States, KD and ALHE have been used synonymously in the Western medical literature, as they were thought to represent variations of the same disease. Some pathologic reports have called for distinguishing KD and ALHE as two separate entities, based on their histologic features. Kimura disease occurs most commonly in the head and neck region and has been described in the orbit, eyelids, and lacrimal gland more frequently than ALHE. Because both diseases can cause proptosis, lid swelling, ocular dysmotility, or a palpable mass, they should be considered in the differential diagnosis of orbital lesions occurring in adults. We report two cases of KD involving the orbit and ocular adnexa, and review additional cases reported in the literature. The ophthalmic literature does not clearly reflect the current understanding that KD and ALHE are best considered two separate clinicopathologic entities.

Angiolymphoid hyperplasia with eosinophilia presenting multinucleated cells in histology: an ultrastructural study

A case of angiolymphoid hyperplasia with eosinophilia arising on the face of a woman is reported. Histologically, the uniqueness of this case is the presence of multinucleated cells (MNCs), besides the conventional dermal changes. Electron microscopy showed that some of the apparent MNCs are clusters of endothelial cells forming immature vascular lumens with numerous microvilli, and the other MNCs displayed the recognized features of fibrohistiocytic or myofibroblastic cells. Immunohistochemically, some MNCs were positive for Ulex europaeus agglutinin and Factor VIII-related antigen. From these findings, some of the MNCs are histologically endothelial sprouts, and the others are fibrohistiocytic cells in the present case.

Cutaneous vascular proliferation. Part II. Hyperplasias and benign neoplasms

This second part of our review about vascular proliferations summarizes the clinicopathologic features of the cutaneous vascular hyperplasias and benign neoplasms. Hyperplasias comprise a heterogeneous group of vascular proliferations that eventually show a tendency to regression. Angiolymphoid hyperplasia with eosinophilia is included within the group of hyperplasias because of its historical denomination and its reactive nature, probably as a consequence of an arteriovenous shunt, although usually the lesions do not regress. Pyogenic granuloma, bacillary angiomatosis, intravascular papillary endothelial hyperplasia, and pseudo-Kaposi's sarcoma qualify as vascular hyperplasias because they regress when the stimulus that initiated them is removed. Benign neoplasms form a large group of hemangiomas with distinctive clinicopathologic characteristics, although some of them are of recent description and may produce diagnostic difficulties. We classified cutaneous benign vascular neoplasms according to their cell lineage of differentiation, for example, endothelial, glomus cell, and pericytic differentiation. Subsequent categories are established according to the size of the involved vessels (capillaries, venules and arterioles, or veins and arteries) or the nature of the proliferating vessels (blood or lymphatic vessels). Capillary and cavernous hemangiomas have been the terms classically used to name the most common variants of benign vascular neoplasms (i.e., infantile hemangiomas), but they are not the most appropriate denominations for these lesions. First, these names are not contrasting terms. Furthermore, most of the socalled "cavernous" hemangiomas are not hemangiomas (neoplasms) at all, but venous malformations. The most important conceptual issue is that, at any point in time, a particular hemangioma has its own histopathologic pattern throughout the depth of the lesion. For these reasons, we classified hemangiomas into superficial and deep categories. Some of the lesions reviewed have been recently described in the literature, and they may histopathologically mimic lesions of Kaposi's sarcoma; these include targetoid hemosiderotic hemangioma, microvenular hemangioma, tufted hemangioma, glomeruloid hemangioma, kaposiform hemangioendothelioma, spindle-cell hemangioendothelioma, and benign lymphangioendothelioma. In each of these lesions, we update and emphasize those clinical and histopathologic features that are helpful for differential diagnosis with lesions of authentic Kaposi's sarcoma in any of its three stages of development (patch, plaque, or nodule).

Hepatic epithelioid hemangioendothelioma: biological questions based on pattern of recurrence in an allograft and tumor immunophenotype

Epithelioid hemangioendothelioma (EHE) is best considered a vascular neoplasm of intermediate malignancy. Although usually progressive, the clinical course is highly unpredictable. The present communication describes a case of extensive recurrent hepatic EHE, limited to the liver allograft and initially manifest as an insidious seeding of individual tumor cells in areas of perivenular inflammation associated with rejection. A detailed immunophenotypic characterization of this and a small series of EHE was carried out in an effort to highlight subtle disease recurrence and to gain possible insights into tumor biology associated with this intriguing disease. In a series of five cases of hepatic EHE, CD34 (QB-END/10) was found to be more sensitive than Factor VIII (F-VIII) for recognition of the disease, similar to previous reports. The former diffusely and distinctly stained both epithelioid and dendritic tumor cells, whereas staining for the latter was focal, indistinct, and showed a high background. Although the tumor cells were negative for some markers of dendritic or macrophage maturation, such as CD1a, S100 protein, Mac 387, CD68, and LN3, there was marked infiltration of hepatic EHE by factor XIIIa + (F-XIIIa), Mac 387+, CD68+, and LN3+ macrophages and dendrocytes, most of which were interpreted as reactive. The "reactive" macrophage and dendrocyte populations were present throughout the fibrotic stroma and intermingled with the epithelioid clusters of EHE. Interestingly, a small subset of tumor cells coexpressed CD34 or F-VIII and F-XIIIa, the last of which is normally restricted to cells of the monocyte/macrophage lineage and cytokine activated microvascular endothelium in vitro. The known association of F-XIIIa+ dendrocytes with granulation tissue, repair and fibrogenesis, and the modulation of F-XIIIa and F-VIII expression by inflammatory cytokines led us to speculate that EHE lesions may derive from primitive "reticuloenothelial" cells that can differentiate along endothelial and dendritic pathways. The EHE lesions may represent a neoplastic analogue of wound healing. Thus, the variability in F-VIII staining, the strong expression of CD34, the infiltration of EHE lesions with F-XIIIa+ dendrocytes, and the coexpression of CD34 and F-XIIIa on a subset of tumor cells may have an important biological basis.

Angiolymphoid hyperplasia with eosinophilia and vascular tumors of the head and neck

PURPOSE

The clinicopathologic distinctions between angiolymphoid hyperplasia with eosinophilia (AHE) and vascular tumors are controversial. Some investigators believe that AHE is a variant of hemangioma, whereas others state that it is an inflammatory phenomenon. To better delineate the clinicopathologic entity of AHE and investigate the efficacy of various treatment regimens, we undertook a retrospective analysis of AHE and compared it with other angiomatous lesions treated at a tertiary referral center.

MATERIALS AND METHODS

We reviewed the histopathologic features of hemangioma, AHE, and angiosarcoma of the head and neck seen in 46 cases at University of California Los Angeles (UCLA) Medical Center between 1950 and 1992. Lesions were evaluated for presence of lymphoid and eosinophilic infiltration, type of endothelial cell, and pattern of vascular proliferation. Patient charts were also reviewed for clinical history and outcome.

RESULTS

The typical findings of AHE were present in 13 cases of conventional hemangioma and angiosarcoma. The clinical data of 8 AHE patients were also reviewed and a benign outcome was observed.

CONCLUSION

We propose that AHE represents an angiomatous neoplasm similar to the hemangioma but characterized by a marked reactive appearance. AHE may comprise part of a spectrum of vascular tumors with differences between lesions depending in part on host-mediated inflammatory and immune responses.

Microvenular hemangioma

Ten examples of a distinctive vascular tumor are reported. These benign acquired lesions typically occur as small, enlarging lesions that favor the extremities, particularly the forearms, of young to middle-aged adults. Clinically, they are purple to red lesions generally thought to be hemangiomas. Histologically, there is a pattern of irregular, branching venules with inconspicuous lumina and lack of cellular atypia. Because the lesions do not conform to existing classifications of vascular tumors, they have been designated with the histologically descriptive name of microvenular hemangioma. Although speculative, they are felt to represent a form of acquired venous hemangioma.

Epithelioid haemangioma (angiolymphoid hyperplasia with eosinophilia) and Kimura's disease in Chinese

Although Kimura's disease has often been considered to be identical to angiolymphoid hyperplasia with eosinophilia (epithelioid haemangioma), recent studies suggest that they are different clinicopathological entities. In this study, we have made a detailed morphological comparison of 10 cases of epithelioid haemangioma and 40 cases of Kimura's disease occurring in the Chinese population. The epithelioid haemangiomas occurred in the subcutaneous tissue, skin and maxillary antrum, whereas Kimura's disease affected the subcutaneous tissue, major salivary glands and lymph nodes. Distinctive features of epithelioid haemangiomas were exuberant proliferation of vessels lined by cuboidal to hobnail endothelial cells with irregular nuclei and cytoplasmic vacuoles, fibromyxoid matrix, involvement of muscular coat of blood vessels and zonation of inflammatory infiltrate towards the peripheral portion of the lesion. Distinctive features of Kimura's disease were florid lymphoid infiltrate with prominent lymphoid follicles, vascularization of germinal centres, germinal centre necrosis, marked eosinophilia with or without eosinophil abscess formation, proliferation of high endothelial venules, and sclerosis. The histological features suggest that epithelioid haemangioma is a proliferation of atypical endothelial cells, possibly neoplastic, that is associated with a variable inflammatory infiltrate, whereas Kimura's disease is primarily an inflammatory condition in which high endothelial venules are usually found.

Angiolymphoid hyperplasia with tissue eosinophilia

Angiolymphoid hyperplasia with eosinophilia is a rare but distinctive clinicopathologic entity. A study of seven cases and review of the literature strongly suggests that both conditions represent a single disease spectrum. The relation of this condition to Kimura's disease is controversial. The descriptive term angiolymphoid hyperplasia with tissue eosinophilia is proposed.

Targetoid hemosiderotic hemangioma

We describe a vascular lesion with characteristic clinical and histologic features. The patients when first seen have a small, single, annular, targetoid-appearing lesion. Histologically it is a noncircumscribed vascular proliferation that may extend into the subcutaneous tissue. The earliest finding appears to be a superficial proliferation of ectatic dermal vascular lumina with intraluminal papillary projections. The endothelial cells are flat or conspicuously epithelioid with solid intraluminal projections. The deeper component is composed of angular, lymphatic-like lumina that concentrate around sweat gland coils, often making small hemangiomatous nodules. Extensive red cell extravasation, inflammatory aggregates, and fibrin thrombi are present. In later stages there is extensive stromal hemosiderin deposition. The endothelial cells are weakly positive for factor VIII-related antigen and strongly positive for Ulex europaeus 1 lectin. The lesion appears to be persistent but self-limited. While appearing clinically benign, it exhibits worrisome histologic features. The nosologic designation of this lesion is uncertain, but it shares certain morphologic features with epithelioid (histiocytoid) hemangioma and progressive lymphangioma. It also poses serious differential diagnostic problems with the early phases of Kaposi's sarcoma.

Angiolymphoid hyperplasia with eosinophilia-acquired port-wine-stain-like lesions: attempt at treatment with the argon laser

An unusual case of angiolymphoid hyperplasia with eosinophilia (ALHE) simulating port-wine stain in a 50-year-old woman is reported. The lesions of ALHE are typically papules or subcutaneous masses that range from light pink to red-brown in color. In addition to the usual histologic findings of ALHE, the biopsy in our patient showed some fibrin-like material and fibrous long-spacing collagen on ultrastructural examination. This unusual lesion necessitates biopsy because the differential diagnosis includes port-wine stain, sarcoidosis, lupus erythematosus, and non-Hodgkin lymphoma (mycosis fungoides). Many different forms of treatment have been attempted for ALHE including radiotherapy, cytotoxic chemotherapy, corticosteroids, and antibiotics. The lesions in our patient responded to argon laser therapy and surgical excision, though there has been recurrence on the border of the treated area. Because laser energy is noncumulative in the tissues and effective in removing the lesions, we recommend it as the treatment of choice for these lesions.

Epitheloid hemangiomatosis mistaken for carcinomatosis

We present a unique case of intra and extra-peritoneal epitheloid hemangioma which was mistaken for diffused carcinomatosis, representing a clinical-pathological problem, and emphasizing the unpredictable behaviour of this tumour. We are dealing with epitheloid vascular tumours, and briefly touch on the differential diagnosis, the principle of biological, pathological and clinical behaviour. Knowledge of this entity would provide an accurate diagnosis and would hence improve dealing with the problem. The conclusion is that this group of Histiocytoid-epitheloid vascular lesions have varying biological potential and this unusual functional state represents a large spectrum of cells, from normal to neoplastic endothelium.

Multiple angiomatous proliferations of ileal stoma following Campylobacter enteritis. Effect of laser photocoagulation

Multiple polypoid sessile tumors arose at the tip of the ileal stoma of a 37-year-old man, who previously underwent proctocolectomy for ulcerative colitis. The lesions developed shortly after a well-established gastrointestinal infection with Campylobacter jejuni with mucosal ulceration. The histological and ultrastructural examination showed angiomatous proliferations, reminiscent of pyogenic granuloma. The destruction of the tumors by laser photocoagulation was followed by superficial ulcerations of the mucosa, which healed without scarring. Small recurrences, however, could not be prevented.

Oral angiolymphoid hyperplasia with eosinophilia

Angiolymphoid hyperplasia with eosinophilia (ALHE) is an unusual and controversial lesion that occurs primarily in the head and neck area; oral involvement is rare. A case involving the labial mucosa, in which immunoglobulin deposits were found in association with a damaged centrally located artery, is described. The clinical and pathologic concepts presented in the literature are discussed. Suggestions that these lesions should be reclassified as epithelioid or histiocytoid hemangiomas may not apply to all of the cases that are acceptable as ALHE by current criteria. Different entities, which include vascular neoplasms, Kimura's disease, and possibly other reactive conditions, may be encompassed in the Western literature as ALHE. Involvement of a small artery and occasionally a vein, often with evidence of vascular damage, was reported in 24% of the cases of ALHE that were reviewed. Single nonrecurrent lesions were seldom found in association with blood eosinophilia, although in the absence of eosinophilia, single and multiple or current lesions occurred in 60% and 40% of the cases, respectively.

Angiolymphoid hyperplasia with eosinophilia. A clinicopathologic study of 116 patients

The clinicopathologic spectrum of angiolymphoid hyperplasia with eosinophilia (ALHE) is reported through a study of 116 cases (67 male and 49 female) submitted to the Armed Forces Institute of Pathology. The lesions are most common in the head-neck region and are characterized by single or multiple smooth-top papules or plaques of varying color. Microscopically, ALHE consists of anomalous vascular proliferations and varying degrees of nodular and diffuse lymphocytic infiltrates with eosinophils at all levels of the corium and subcutaneous tissue. In fifty-three cases an arterial structure, confirmed by the presence of an internal elastic lamina, was observed in close association with venular structures or was the site of endothelial cell proliferation. ALHE comprises a spectrum of unusual vascular proliferation with inflammation, encompassing such entities as inflammatory angiomatous nodules, pseudo or atypical pyogenic granuloma, histiocytoid hemangioma, epithelioid hemangioma, and Kimura's disease. The existence of arterial structures among venules and endothelial cell proliferations suggests the presence of arteriovenous (AV) shunts, which may help explain the pathogenesis and biologic behavior of this condition.

Hemangioendothelioma of bone. A case report with massive tissular necrosis

Hemangioendothelioma or histiocytoid hemangioma of bone is a low grade tumor, which may be a quite indolent and controlable lesion, even in the rare case it develops distant metastasis. Our case presents features of such lesion by light microscopy and with a peroxidase-antiperoxidase technique for Factor VIII related antigen, but it exhibits an unusual extensive tissular necrosis. Necrosis does not seems to make worse the usual course, after six years and ten months of conservative surgical treatment and radiation therapy.

Ultrastructure of cerebellar capillary hemangioblastoma. II. Mast cells and angiogenesis

The topographic distribution, population density, and ultrastructural features of mast cells were studied in six cases of cerebellar capillary hemangioblastoma. The vascular area of tumor tissue contained large numbers of mast cells (6.3 cells/high power field, X 400) in comparison with hyalinized area (0.3 cell) and adjacent cerebellar tissue (less than 0.1 cell). Close association of mast cells with endothelial cells and stromal cells was found. The morphology of mast cell granules and their degranulation through dissolution of granule contents and exocytosis were illustrated. The findings suggest that an increased number of mast cells may represent one of the characteristic histological features of capillary hemangioblastoma, and continuous degranulation of mast cell granules with release of heparin may play an important pathophysiologic role in the vascular proliferation and expansion of the tumor.

Histiocytoid hemangioma of the skin and scapula. A case report with electron microscopy and immunohistochemistry

This report presents the interesting case of a 50-year-old white man with an unusual benign tumor composed predominantly of a proliferation of atypical endothelial cells combined with a variable inflammatory response. This case represents an instance of the recently renamed entity "histiocytoid hemangioma" in which two organ systems are involved. Both skin and bone showed typical lesions. No physical connection jointed the separate lesions. The results of examination by light microscopy, electron microscopy, and immunoperoxidase examination for lysozyme and Factor VIII are reported. The significance of this case is that it supports the concept of classifying similar vascular lesions, despite varied organ system origin, into a single entity, the histiocytoid hemangioma.

Angiokines, angiogenesis and angiolymphoproliferative syndromes (ALPS)

In earlier experiments we had noted that transformed and leukemic leukocytes produced an RNA-rich angiogenic lymphokine. The formation of capillaries is a stepwise process in which reticulum cells first become detached and attracted to a site (mobilization and migration along a reticulin network). This is followed by local proliferation and finally by elongation and alignment against a basal membrane in tubular geometry. Coincidental with the last step is a biochemical and immunochemical differentiation of the endothelial cells manifested by the appearance of alkaline phosphatase, angiotensin-converting enzyme, factor VIII and the generation of receptors for thrombin as well as the capacities to produce prostacyclin and fibronectin on demand. It is postulated that there may be not one but several angiogenic lymphokines (angiokines) for each step of capillary development. Angiokine 1 (AK1) for the mobilization-chemotactic-migration, AK2 for the local proliferative, and AK3 for differentiating-morphogenic events. The above postulate aids in the classification and understanding of a number of angiolymphoproliferative syndromes since these reflect different disorders of the stepwise vessel formation. The association and the simultaneous proliferation of vascular and lymphoid elements is a feature that a number of lymphoproliferative disorders, of otherwise differing nature, have in common. To this effect they have been grouped in this study as angiolymphoproliferative syndromes (ALPS). These are a group of prelymphomatous or prelymphomogenic clinicopathologic entities in which proliferation of a lymphoid element (cell) is coupled with the accelerated development of blood capillaries and postcapillary venules.

Neoplastic angioendotheliomatosis. Histologic, immunohistochemical, and ultrastructural findings in two cases

Two cases of neoplastic angioendotheliomatosis are described. Both patients presented with subacute development of dementia punctuated by focal neurologic signs. Postmortem examination in both cases disclosed a vasculocentric distribution of neoplastic cells in many organs. Two characteristic histologic patterns were seen: (1) distension of vascular spaces by free-floating, intraluminal cells and (2) asymmetric, subendothelial tumor growth. Intravascular tumor and secondary vascular changes were associated with microinfarcts in involved organs. Immunohistochemical localization of factor VIII-related antigen in the neoplastic cells of one case provides evidence for their endothelial origin. The neoplastic cells in both cases exhibited similar but nonspecific ultrastructural features. In addition, dramatic fine structural changes including the acquisition of numerous pinocytotic vesicles and bundles of fine filaments with periodic densities were found in the non-neoplastic endothelial cells.

Ultrastructure of mast cells in growing and involuting stages of hemangiomas

Mast cells from 11 patients with growing strawberry (capillary) hemangiomas and cellular hemangiomas and from ten patients with involuting stages of strawberry hemangiomas were investigated electron microscopically. Two types of mast cells were evident: numerous elongated, fibroblastic cells and a few round, classic cells. The mast cells in growing hemangiomas contained many small, simple-type granules in various stages of development. It is possible that, owing to the immaturity of these granules, mast cells have different, probably weaker, functional activities. Mast cells in involuting stages of hemangiomas were filled primarily with compound-type granules, showing typical parallel, concentric lamellae or crystalloid structures, which were similar to the mature mast cells in normal skin.

Epithelioid hemangioendothelioma: a vascular tumor often mistaken for a carcinoma

Epithelioid hemangioendothelioma is a unique tumor of adult life which is characterized by an "epithelioid" or "histiocytoid" endothelial cell. Forty-one cases of this rare tumor have been recognized at the Armed Forces Institute of Pathology. They may occur in either superficial or deep soft tissue, and in 26 cases appeared to arise from a vessel, usually a medium-sized or large vein. They are composed of rounded or slightly spindled eosinophilic endothelial cells with rounded nuclei and prominent cytoplasmic vacuolization. The latter feature probably represents primitive lumen formation by a single cell. The cells grown in small nests or cords and only focally line well-formed vascular channels. The pattern of solid growth and the epithelioid appearance of the endothelium frequently leads to the mistaken diagnosis of metastatic carcinoma. The tumor can be distinguished from a carcinoma by the lack of pleomorphism and mitotic activity in most instances and by the presence of focal vascular channels. Ultrastructural study in four cases confirmed the endothelial nature of the tumor in demonstrating cells surrounded by basal lamina, dotted with surface pinocytotic vesicles, and occasionally containing Weibel-Palade bodies. Follow-up information in 31 cases indicated that 20 patients were alive and well following therapy; three developed local recurrences and six metastases. It is suggested the term epithelioid hemangioendothelioma be used to designate these biologically "borderline" neoplasms. The significance of the epithelioid endothelial cell is not entirely clear. Since it may be observed in both benign and malignant vascular lesions, its presence alone does not define a clinicopathologic entity.

Epithelioid hemangioendothelioma: a vascular tumor often mistaken for a carcinoma

Epithelioid hemangioendothelioma is a unique tumor of adult life which is characterized by an "epithelioid" or "histiocytoid" endothelial cell. Forty-one cases of this rare tumor have been recognized at the Armed Forces Institute of Pathology. They may occur in either superficial or deep soft tissue, and in 26 cases appeared to arise from a vessel, usually a medium-sized or large vein. They are composed of rounded or slightly spindled eosinophilic endothelial cells with rounded nuclei and prominent cytoplasmic vacuolization. The latter feature probably represents primitive lumen formation by a single cell. The cells grown in small nests or cords and only focally line well-formed vascular channels. The pattern of solid growth and the epithelioid appearance of the endothelium frequently leads to the mistaken diagnosis of metastatic carcinoma. The tumor can be distinguished from a carcinoma by the lack of pleomorphism and mitotic activity in most instances and by the presence of focal vascular channels. Ultrastructural study in four cases confirmed the endothelial nature of the tumor in demonstrating cells surrounded by basal lamina, dotted with surface pinocytotic vesicles, and occasionally containing Weibel-Palade bodies. Follow-up information in 31 cases indicated that 20 patients were alive and well following therapy; three developed local recurrences and six metastases. It is suggested the term epithelioid hemangioendothelioma be used to designate these biologically "borderline" neoplasms. The significance of the epithelioid endothelial cell is not entirely clear. Since it may be observed in both benign and malignant vascular lesions, its presence alone does not define a clinicopathologic entity.

Regressing atypical histiocytosis: a cutaneous proliferation of atypical neoplastic histiocytes with unexpectedly indolent biologic behavior

Regressing atypical histiocytosis (RAH) of skin is a cutaneous noduloulcerative proliferation of atypical neoplastic histiocytes with concomitant polymorphous inflammation, frequently pronounced epidermal hyperplasia, and an unexpectedly indolent biologic course. Spontaneous regression and recurrence without systemic spread were the course in follow-up periods of over six years. Histopathologically, characteristic-appearing atypical mononuclear and multinucleated "RAH" cells showed erythrophagocytosis as well as ultrastructural, surface marker, and enzyme cytochemical features indicating histiocytic differentiation. Cytogenetic analysis showed aneuploidy and several marker chromosomes including 14q+. Its benign biologic course clearly distinguished this entity from malignant histiocytosis, large cell lymphoma, and Hodgkin's disease. The histiocytic atypical cells further distinguished it from the T-cell lesions of the skin, such as mycosis fungoides and lymphomatoid papulosis. This entity is readily confused with malignant lymphoreticular disease, melanoma, or squamous carcinoma.

Human dermal microvasculature: II. Enzyme histochemical and cytochemical study

An enzyme histochemical and cytochemical study of normal dermal microvasculature showed that respiratory enzymes, lipase and non-specific esterase occurred in all vascular segments. Lysosomal enzymes were also widely distributed and acid phosphatase activity was localized in lysosomes, Golgi apparatus and small portions of endoplasmic reticulum of both endothelial cells and pericytes. Alkaline phosphatase activity, however, was confined to the arterial side and tip of the capillary loop where it occurred in vesicles along the luminal surface of the endothelium and in junctions between endothelial cells. The localization of nucleoside phosphatase activity within the endothelium varied according to substrate; with adenosine triphosphate as substrate, the reaction product occurred in vesicles distributed throughout the endothelial cells; with adenosine diphosphate it was limited to vesicles along the luminal surface; and with adenosine monophosphate, activity was mostly localized to the lateral surfaces of endothelial cells. These findings suggest functional variation between different vascular segments and between various components of the endothelium. Attempts to demonstrate a specific Na+K+ adenosine triphosphatase (transport ATPase) within the endothelium were not successful.

Angiolymphoid hyperplasia with eosinophilia: report of a case with penile lesions

A case of angiolymphoid hyperplasia with eosinophilia of the penis is reported. In addition to the proliferation of swollen endothelial cells with features of histiocytes ("histiocytoid endothelial cells"), the lesions also showed a remarkable proliferation of pericytes both in relation to formed vascular channels and away from them. The authors consider that the inflammatory component is associated with even the earliest stages in the development of the lesions and that it not be dismissed as secondary.

Angiolymphoid hyperplasia with eosinophilia simulating lymphadenopathy

A case of angiolymphoid hyperplasia (AHE) with eosinophilia presenting with recurrent inguinal swellings simulating lymphadenopathy is described. Tissue was examined by light microscopic techniques, electron microscopy and immunohistochemistry. Electron microscopy showed large numbers of cytoplasmic filaments and bizarre Weibel-Palade bodies in the atypical endothelial cells that characterize AHE. Factor VIII related antigen was demonstrated in a small proportion of these cells by immunoperoxidase staining. The absence of staining for lysozyme and alpha 1 antitrypsin does not support the concept that these cells are histiocytic in nature. The prominent lymphoid and plasma cell proliferative elements in this case showed a polytypic staining pattern for immunoglobulin. An unusual reticular staining pattern for IgE was observed in the lymphoid follicles. The nature and pathogenesis of AHE is discussed in the light of previous publications and the findings in this case.

Human dermal microvasculature: I. Its segmental differentiation. Light and electron microscopic study

Light microscopic examination of I micrometer thick epoxy resin sections of human skin preserved in fixative normally used for electron microscopy allows division of the microvasculature of the reticular and superficial dermis into several distinct segments. More precise delineation of these components can be achieved by correlative study using electron microscopy. Measurement of vessel diameter in tissue sections is of limited value in vessel classification because there is a wide overlap between different vascular segments and the results are influenced by the type of fixative used for processing the tissue. Detailed observation of the morphological characteristics of the endothelium and its investment, including the elastic and basal laminae, is consider preferable for identifying individual vascular segments. Differences in body region do not appear to have any obvious influence on vessel structure although there are regional differences in vessel density and arrangement. In comparison with earlier studies on animal tissues or human skin, no structures resembling arteriovenous shunts or precapillary sphincters were observed in the present investigation. However, closed fenestrae and other structures thought to be transendothelial channels were often found at the tips of capillary loops adjacent to the epidermis.