Lymphangioma-like variant of Kaposi's sarcoma: clinicopathologic study of seven cases with review of the literature

Surgical Treatment for Benign Lymphangioendothelioma After Two Incomplete Excisions: A Case Report and Literature Review

Benign lymphangioendothelioma (BL) is a rare, poorly identified, slow-growing benign vascular lesion characterized by asymptomatic, solitary, well-demarcated macules, or by mildly infiltrated plaque. We report a case of an atypical BL that arose as a tender, protuberant, flesh-colored mass with cyanotic vesicles, and then progressed to a persistent exudative wound after two incomplete excisions. The patient was also diagnosed with thoracic duct narrowing. Although the stenosis was removed by surgery, the right lower extremity ulceration and exudation did not improve. Thus, we performed a thorough excision and split-thickness skin graft transplant following vacuum sealing drainage, and eventually the patient had a favorable functional and cosmetic outcome. A biopsy revealed irregular, dilated vascular spaces lined with a single layer of flat endothelial cells extending from the superficial dermis to the subcutis that did not reach the striated muscles. Additionally, by reviewing the literature on BL, in this paper we summarize the diverse pathogenic, morphological, and immunohistochemical presentations for this rare disease, as well as the histopathological differential diagnosis of lymphangiomatosis, Kaposi's sarcoma, and angiosarcoma.

Angiosarcoma-like Kaposi Sarcoma: A Distinctive Histomorphologic Variant Representing an Important Diagnostic Pitfall

Kaposi sarcoma (KS) is a rare low-grade angioproliferative neoplasm associated with human herpesvirus 8 (HHV-8) infection with multiple clinical subtypes and varying histopathologic patterns. Histologically, many different variants of KS have been reported, yet all can be difficult to recognize and must be differentiated from other vascular tumors. In this report, we studied fourteen cases of a newly described variant of KS reminiscent of a well-differentiated angiosarcoma (angiosarcoma-like KS). All cases showed a diffuse, ill-defined infiltrative dermal-based lesion composed of numerous anastomosing vascular channels of varying caliber lined by a single layer of endothelium with minimal pleomorphism. The vascular proliferation ramified through the dermis and dissected the collagen bundles along with infiltration into the subcutaneous fat and around skin appendages. All cases showed expression of vascular markers (CD31, CD34, and ERG) and were positive for HHV-8. None showed the classic histopathology associated with KS. Without clinical guidance these tumors can be difficult to recognize as KS, creating significant diagnostic challenges. Our study expands on a rare histologic variant of KS that ought to be considered in the differential diagnosis of any cutaneous well-differentiated angiosarcoma. Awareness of this variant of KS is of important for proper diagnosis and management of these patients; thus, careful attention to the histomorphology and clinical history can help lead the pathologist to the correct diagnosis.

Epithelioid Kaposi Sarcoma: A New Histological Variant

ABSTRACT

Cutaneous Kaposi sarcoma (KS) covers a broad spectrum both clinically and pathologically. Some histological patterns of KS may be difficult to recognize and must be differentiated from other vascular neoplasms. We report on a 56-year-old Peruvian man who had been diagnosed with classical KS on the right foot 2 years before the present episode. He presented in our clinic with new lesions on the left foot. Histopathological findings included areas showing epithelioid cells with moderate pleomorphism, growing in solid sheets. Immunohistochemistry showed strong nuclear staining with a granular nuclear staining pattern for human herpesvirus 8 in the epithelioid cells. A diagnosis of epithelioid Kaposi sarcoma was made, which should be considered a new histological variant.

Head and Neck Kaposi Sarcoma: Clinicopathological Analysis of 11 Cases

Kaposi sarcoma (KS) of the head and neck area is uncommon with limited published case series. Our routine and consultation files were reviewed for histologically and immunohistochemically proven KS affecting any cutaneous or mucosal head and neck site. Ten males and one female aged 42-78 years (median, 51 years; mean, 52 years) were retrieved. Eight patients were HIV-positive and three were HIV-negative. The affected sites were skin (n = 5), oral/oropharyngeal mucosa (n = 5), and lymph nodes (n = 3) in variable combination. The ear (pinna and external auditory canal) was affected in two cases; both were HIV-negative. Multifocal non-head and neck KS was reported in 50% of patients. At last follow-up (12-94 months; median, 46 months), most of patients were either KS-free (n = 8) or had ongoing remission under systemic maintenance therapy (n = 2). One patient was alive with KS (poor compliance). Histopathological evaluation showed classical features of KS. One case was predominantly sarcomatoid with prominent inflammation mimicking undifferentiated sarcoma. Immunohistochemistry showed consistent expression of CD31, CD34, ERG, D2-40 and HHV8 in all cases. This is one of the few series devoted to head and neck KS showing high prevalence of HIV-positivity, but also unusual presentations in HIV-negative patients with primary origin in the skin of the ear and the auditory canal. KS should be included in the differential diagnosis of difficult-to-classify spindle cell lesions at this uncommon location.

Malignant mesenchymal neoplasms of the dermis and subcutis mimicking benign lesions: a case-based review

In this short review, malignant mesenchymal neoplasms of the dermis and subcutis mimicking benign lesions and their differential diagnoses are discussed. These include plaque-like dermatofibrosarcoma protuberans, superficial low-grade fibromyxoid sarcoma, low-grade superficial malignant peripheral nerve sheath tumour, epithelioid sarcoma, pseudomyogenic haemangioendothelioma, Kaposi sarcoma mimicking cavernous haemangioma and benign lymphangioendothelioma, and rare forms of angiosarcoma mimicking a benign vascular lesion.

Allelopathic effects of volatile organic compounds from Eucalyptus grandis rhizosphere soil on Eisenia fetida assessed using avoidance bioassays, enzyme activity, and comet assays

Allelopathy has been identified as an underlying mechanism of detrimental environmental impacts within commercial plantations. Eucalyptus spp. are known to generate huge amounts of volatile organic compounds (VOCs) that can function as phytotoxins and thus inhibit other plants. In the present study, biochemical markers, including activities of acetylcholinesterase (AChE) and oxidative stress enzymes, such as superoxide dismutase (SOD) and glutathione S-transferase (GST), were assayed to assess changes in Eisenia fetida at the physiological level induced by different doses of VOCs as part of an acute toxicity test over 7 and 14-day exposures. In addition, the toxicities of VOCs were investigated using a soil avoidance test and comet assay. The results revealed that E. fetida exhibited significant avoidance behavior towards the highest concentrations of undecane, decane, 2,4-dimethyl heptane, and 2,2,4,6,6-pentametyl heptane. The tail DNA percentages were significantly increased for all experimental treatments relative to control. However, under the treatments of VOCs, Olive tail moment content and comet tail length also display an obvious increase compared to control, except for that of octane, undecane and decane treatments. As VOC concentrations and durations increased in the soil, activities of AChE, SOD, and GST were either stimulated or inhibited. Among the VOCs, decane, 2,4-dimethyl heptane, 2,2,4,6,6-pentamethyl heptane, and 2,4-di tert buyl phenol exerted stronger effects on enzymatic activities. In summary, VOCs in rhizosphere soils of E. grandis might exert a toxic impact on E. fetida, among which 2,4-dimethyl heptane, 2,2,4,6,6-pentamethyl heptane, and 2,4-di tert buyl phenol have the strongest effects.

Histopathology of Spindle Cell Vascular Tumors

Vascular tumors with a spindled morphology represent a diagnostic challenge in soft tissue pathology. It may be difficult to distinguish certain benign entities in this category from spindled vascular tumors of intermediate malignancy or even spindled variants of angiosarcoma. This article focuses on vascular tumors characterized by a predominantly spindled morphology, including spindle cell hemangioma, acquired tufted angioma (angioblastoma of Nakagawa), kaposiform hemangioendothelioma, Kaposi sarcoma, and spindle cell variants of angiosarcoma.

Lymphangioma-like Kaposi Sarcoma in Transplant-Associated Iatrogenic Immunosuppression: A Case Report

Lymphangioma-like Kaposi sarcoma (LLKS) is a rare histologic presentation of Kaposi sarcoma (KS), with only 28 cases reported in the literature. LLKS has been described in acquired immunodeficiency syndrome and in endemic African-type as well as classic indolent KS. We present the 1st reported case of LLKS in a transplant-associated iatrogenic immunosuppressed patient.

Histopathological analysis of vesicular and bullous lesions in Kaposi sarcoma

Background

In this study, the clinical and morphological features of vesiculobullous lesions observed in Kaposi sarcoma are analyzed, and the features of bullous Kaposi sarcoma cases are emphasized.

Methods

A total of 178 biopsy materials of 75 cases diagnosed as classic-type cutaneous Kaposi sarcoma were reviewed. Twenty-five cases showing vesiculobullous features were included in the study. Tumor, epidermis, dermis, and clinical data regarding these cases was evaluated.

Results

Vesicular changes were observed in 21 (12%) out of 178 lesions of the 75 cases, while bullous changes were present in only 4 (2%). In all cases where vesicular and bullous changes were detected, tumor, epidermis, and dermis changes were similar. All cases were nodular stage KS lesions, whereas hyperkeratosis and serum exudation in the epidermis, marked edema in the dermis, and enlarged lymphatic vessels and chronic inflammatory response were observed.

Conclusions

Our findings suggest that changes in vascular resistance occurring during tumor progression are the most important factors comprising vesiculobullous morphology.

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1646397188748474

A unique cause of a rare disorder, unilateral macromastia due to lymphangiomatosis of the breast: a case report

Macromastia and in particular unilateral macromastia is a rare clinical entity. It relates to massive enlargement of the breast in non-obese women. This case report describes an initially mild unilateral asymmetry occurring nine months postpartum in a 33-year-old female. However, following her second pregnancy within 12 months, her left breast became severely enlarged. This did not improve on delivery. No discrete lesion was seen on imaging and no significant abnormalities were seen in her blood chemistry. Surgical treatment was a mammoplasty and 580 g of mammary tissue was removed. Grossly, there was spongiform subcutaneous tissue with diffuse extension. On histology, this consisted of a highly complex and diffuse pattern of infiltration and of cavernous empty channels lined by a delicate attenuated endothelium which was CD34 and D2-40 positive. The appearances were consistent with lymphangiomatosis, more commonly encountered in the limbs, heretofore. Lymphangiomatosis has not been previously described in breast tissue and only a single case report exists for such a lesion in axillary tissue. Treatment of such lesions in the periphery by surgical excision is very difficult and excision without being radical can be impossible. Follow up of our patient, shows no evidence of recurrence in this patient. Our case report describes the clinicopathological features, differential diagnosis to be considered and treatment, in addition to reviewing the relevant literature.

Histological variants of cutaneous Kaposi sarcoma

This review provides a comprehensive overview of the broad clinicopathologic spectrum of cutaneous Kaposi sarcoma (KS) lesions. Variants discussed include: usual KS lesions associated with disease progression (i.e. patch, plaque and nodular stage); morphologic subtypes alluded to in the older literature such as anaplastic and telangiectatic KS, as well as several lymphedematous variants; and numerous recently described variants including hyperkeratotic, keloidal, micronodular, pyogenic granuloma-like, ecchymotic, and intravascular KS. Involuting lesions as a result of treatment related regression are also presented.

Angiosarcomas, a heterogeneous group of sarcomas with specific behavior depending on primary site: a retrospective study of 161 cases

BACKGROUND

Angiosarcomas are rare, heterogeneous and a retrospective study was conducted to describe their natural history.

PATIENTS AND METHODS

We reviewed 161 files of angiosarcoma treated in three institutions of the French Sarcoma Group from 1980 to 2004. Survival and prognostic factors for survival were analyzed.

RESULTS

Median age was 52 years. Primary sites were the breast (35%), skin (20%) and soft tissues (13%). At initial diagnosis, 31 (19%) had metastases. Surgery was the first treatment in 121 (75%) patients combined with chemotherapy or radiotherapy in 34 and 32, respectively. Ninety (74%) of these 121 patients relapsed, mostly locally (50). With an average time since initial diagnosis of 8.1 years, 123 (76%) patients progressed and 76 (47%) died. Median survival was 3.4 years [95% confidence interval (CI) 2.4-5.8], and the 5-year overall survival (OS) rate was 43% (95% CI 33-53). In multivariate analysis, liver primary site [relative risk (RR) = 12.62], performance status (PS) of two or more (RR = 3.83), presence of metastases at diagnosis (RR = 2.50), soft tissue tumor (RR = 0.31) were correlated to OS. PS, liver and soft tissue tumors were identified as independent prognostic factors for progression-free survival.

CONCLUSIONS

Angiosarcomas have an overall poor outcome, but with a clearly distinct prognosis depending on the primary site.

Lymphedematous HIV-associated Kaposi's sarcoma

BACKGROUND

Advanced Kaposi's sarcoma is frequently associated with chronic lymphedema (cLO). The histopathological features of lymphedematous HIV-associated KS (KS) are poorly documented and the co-existence of fibroma-like nodules in lymphedematous KS is under-recognized. The aims of this study were to assess the clinicopathological spectrum and diagnostic difficulties associated with lymphedematous KS and to highlight the clinicopathological profile of fibroma-like nodules. In addition, the pathogenesis of fibroma-like nodules and cLO is revisited.

MATERIALS AND METHODS

Prospective 17-month clinicopathological study of all biopsies from patients with lymphedematous KS.

RESULTS

Seventy-four biopsies, the majority from the lower limbs, from 41 patients were evaluated. Nineteen, 14, five and three patients had one, two, three or four biopsies each, respectively. In 14 biopsies, there was poor clinicopathological correlation of KS stage. Exclusive lesional KS (patch, plaque, nodule or lymphangioma-like) was identified in 29 biopsies; 23 and eight biopsies demonstrated KS or fibroma-like morphology and the adjacent dermis demonstrated cLO. There was variable intratumoral and peritumoral venous compression and lymphatic dilatation. Fourteen biopsies demonstrated cLO exclusively. Smaller fibroma-like nodules lacked KS spindle cells, whereas >5 mm nodules demonstrated focal KS spindle cell proliferation and aggregation on extensive sectioning. The subcutis of 42 biopsies demonstrated variable fibrosis, hemosiderin deposits, lymphocytes, plasma cells, KS, interstitial granular material and pools of lymph fluid. Subcutaneous abscesses were identified in six biopsies. All biopsies had variable epidermal features of cLO.

CONCLUSIONS

cLO influences clinicopathological correlation of KS stage and may also mask the presence of KS and the co-existence of subcutaneous abscesses. Smaller fibroma-like nodules are hypothesized to be a manifestation of cLO that have the potential to acquire the characteristics of KS. Lymphatic and venous obstruction, protein-rich interstitial fluid, tissue hemosiderin and subcutaneous infection are hypothesized to play a combined role in the evolution and perpetuation of cLO.

Angiosarcoma arising in a lymphedematous abdominal pannus with histologic features reminiscent of Kaposi's sarcoma: report of a case and review of the literature

BACKGROUND

Despite common endothelial origins, angiosarcoma and Kaposi's sarcoma are clinically and histologically distinct vascular proliferations. The development of angiosarcoma in a chronically edematous abdominal pannus is extremely uncommon. Similarly, tumors with the combined histologic features of angiosarcoma and Kaposi's sarcoma have rarely been described.

METHODS

We reviewed the literature on angiosarcoma arising in a lymphedematous abdominal pannus and evaluated an 81-year-old morbidly obese woman who had profound, long-standing edema of the lower abdominal wall in which an aggressive vascular tumor developed.

RESULTS

Three clinically similar cases were identified in the literature. All patients were women who generally experienced rapid disease progression. In addition, in our patient, sequential cutaneous sampling from different lesional sites demonstrated disparate histologic changes, ranging from those of classic Kaposi's sarcoma to high-grade angiosarcoma, to areas with combined features of the two tumors. A polymerase chain reaction performed on lesional tissue was negative for human herpesvirus-8 DNA.

CONCLUSION

It is important to note that angiosarcoma may develop in the abdomen in association with chronic lymphedema, as demonstrated by the cases noted in this report. In addition, our case highlights the difficulty in differentiating histologically angiosarcoma from Kaposi's sarcoma in some situations, and demonstrates the value of close clinicopathologic correlation and sequential tissue sampling in evaluating problematic cases.

Lymphangioma-like Kaposi sarcoma

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.

Aggressive Behavior of Classical Kaposi's Sarcoma and Coexistence With Angiosarcoma

An 82-year-old Caucasian man presented with initially asymptomatic livid red plaques on the plantar surface of the feet that become confluent and evolved into invasively growing nodules accompanied by massive edema. Histology allowed a diagnosis of the classical form of Kaposi's sarcoma; the serology test result for HIV was negative, whereas the associated human herpes virus type 8 was detected by polymerase chain reaction on the skin sample. Over the subsequent 6 months, skin lesions become vegetative and partially necrotic, and extended to the hands and eyelids. Chemotherapy with vinblastine appeared to stabilize the cutaneous disease, but the patient developed a massive gastrointestinal hemorrhage secondary to dissemination to the stomach. Twelve months after the onset of the disease, vegetative and easily bleeding lesions progressively occluded the mouth of the patient: histological features were consistent with a low-grade angiosarcoma distinct from that of Kaposi's sarcoma. The patient could not chew and swallow anymore; he was put on an artificial nutrition but died shortly thereafter. This case illustrates that, even in its classical form, Kaposi's sarcoma may be a malignant, rapidly progressing tumor.

LEARNING POINTS

a) The extent and rate of spread of initial skin lesions should be considered to be early signs of aggressive dissemination, even in the absence of other variables (i.e., histological pattern, human herpes virus type 8 positive mononuclear cells) associated with progression of the disease. b) An endoscopy may be useful given the high prevalence of gastrointestinal involvement. c) When classical Kaposi's sarcoma displays aggressive behavior a second, primary malignant tumor arising from the vascular tissue should be investigated.

TAKE-HOME MESSAGE

Even in its classical form, Kaposi's sarcoma may be a malignant, rapidly progressing tumor with visceral involvement; also, a second malignancy may occur in nearly one patient of four. Because localized skin lesions can regress completely with radiotherapy, watchful waiting is probably inappropriate in most cases.

Vascular tumors of the skin: A selective review

Cutaneous vascular proliferations are a vast and complex spectrum. Many appear as hamartomas in infancy; others are acquired neoplasms. Some vascular proliferations are hyperplastic in nature, although they mimic hemangiomas, i.e., neoplasms. The vast majority of the vascular lesions are hemangiomas. Between the hemangiomas and frankly angiosarcomas, there is a group of neoplasms that are angiosarcomas, albeit ones of low grade histologically and, probably, biologically. The term "hemangioendothelioma" has been created to encompass these neoplasms. Vascular proliferations are, fundamentally, composed of endothelial cells. Some hemangiomas, however, contain also abundant pericytic, smooth muscle, or interstitial components, or a combination of them. These heterogeneous cellular components are present usually in hemangiomas. Some of the newly described vascular proliferations, however, are difficult to differentiate from some of the angiosarcomas. Others are markers, occasionally, of serious conditions such as Fabry's Disease (angiokeratoma) and POEM's syndrome (glomeruloid hemangioma). Kaposi's sarcoma continues to be an enigma. The demonstration of Herpes virus 8 in this condition raises doubt about its neoplastic nature. The demonstration of endothelial differentiation of its nodular lesions is tenuous and its true nature remains unresolved. While physicians have known about post-mastectomy angiosarcomas from the origin of the radical mastectomy, a new group of unusual vascular proliferations of the mammary skin are being defined. These lesions arise in the setting of breast-conserving surgical treatment with adjuvant radiation therapy. The incubation period is usually 3 to 5 years, in contrast with the 10, or more, in classical cases of post-mastectomy angiosarcoma. These lesions usually are subtle, both clinically and histologically, in contrast with the "classical," dramatic presentation of mammary angiosarcoma. The spectrum of findings ranges from "simple" lymphangiectasia-like vascular proliferations to unequivocal angiosarcomas. The pathogenesis of these lesions remains a mystery. There are very few clues that allow one to separate hemangiomas from angiosarcomas. The presence of heterologous cellular elements and, particularly, well-developed smooth muscle components tends to favor a hemangioma. Similarly, the presence of thrombosis usually supports hemangioma. Nevertheless, there are no unequivocal or reliable individual diagnostic criteria. A thorough knowledge of the different conditions and their differential diagnoses eventually leads to the proper diagnosis in most cases.

Benign vascular proliferations in irradiated skin

Several types of cutaneous vascular proliferations have been described in areas of irradiated skin, including both benign lesions, such as benign lymphangiomatous papules, atypical vascular lesions, or benign lymphangioendothelioma, and malignant neoplasms such as high-grade angiosarcomas. This report describes the clinicopathologic features of 15 cases of different types of benign cutaneous vascular proliferations arisen within irradiated skin. All patients were female ranging in age from 33 to 72 years, and they had received postoperative external radiotherapy for treatment of breast carcinoma (14 cases) or ovarian carcinoma (one case). In those cases in which the latency interval period between radiotherapy and the development of the vascular lesion was known from the clinical records, the latency interval period elapsed between radiotherapy and diagnosis of the vascular lesion ranged from 3 to 20 years. The most common clinical presentation of the cutaneous lesions consisted of papules, small vesicles, or erythematous plaques on the irradiated field. Histopathologically, most lesions consisted of irregular dilated vascular spaces, with a branching and anastomosing pattern, thin walls, and lymphatic appearance involving the superficial dermis. A discontinuous single layer of endothelial cells with flattened nuclei lined these vascular channels, and numerous small stromal papillary formations also lined by endothelial cells projected into the lumina of the dilated lymphatic vessels. These cases were classified as benign lymphangiomatous papules or plaques. Two cases showed different histopathologic findings because they consisted of poorly circumscribed and focally infiltrating irregular jagged vascular spaces involving the entire dermis and lined by inconspicuous endothelial cells. In some areas these irregular slit-like vascular spaces dissected collagen bundles of the dermis. These cases were classified as atypical vascular proliferations mimicking benign lymphangioendothelioma or patch-stage Kaposi's sarcoma. All cases showed similar immunohistochemical findings and the endothelial cells lining the vascular spaces expressed immunoreactivity for CD31, but they stained only focally positive for CD34 or were negative for this marker. Immunohistochemical investigations for alpha-smooth muscle actin failed to demonstrate a complete peripheral ring of actin-positive pericytes in most of the neoformed vascular structures. This immunohistochemical profile also supported the lymphatic nature of these vascular proliferations developed in irradiated skin. Although some of these lesions may mimic histopathologically patch-stage Kaposi's sarcoma or well-differentiated angiosarcoma, the follow-up of the patients of this series demonstrated that the vascular proliferations arisen in irradiated skin invariably showed a benign biologic behavior.

Benign lymphangioendothelioma (acquired progressive lymphangioma): a lesion not to be confused with well-differentiated angiosarcoma and patch stage Kaposi's sarcoma: clinicopathologic analysis of a series

The clinicopathologic features of 12 cases of benign lymphangioendothelioma (acquired progressive lymphangioma) are reported. There were five male and seven female patients. Age at diagnosis ranged from 17 to 90 years (median age, 54 yrs). Development of a single macular/papular hemangiomatous or pigmented lesion was the main presenting symptom. Symptom duration before diagnosis ranged from 2 months to 20 years (median, 5.5 yrs). Tumor size ranged from 0.3 cm to 10 cm (median. 1.5 cm). Location included skin of the head and neck (n = 5), back (n = 1), breast (n = 1), shoulder (n = 1), forearm (n = 1), plantar aspect of the foot (n = 2), and oral mucosa (n = 1). No patient had any other concomitant vascular anomaly (for example, lymphangiomatosis) or was suspected to have acquired immunodeficiency syndrome. Treatment consisted of excisional biopsy in nine patients, incisional biopsy in two, and wide excision in one. Follow-up information on nine patients (range, 4-40 mos; median, 12 mos) showed two local recurrences in one patient. Microscopically, the lesions consisted of anastomosing, often widely dilated vascular structures developing in the superficial dermis. As the lesion grew within deeper dermis, the vascular spaces collapsed and dissected the dermal collagen in an angiosarcoma-like pattern. The lining endothelium was flat and monolayered, with little or no cytologic atypia and no evident mitoses. Some vascular structures contained stromal papillary projections resembling papillary endothelial hyperplasia, and intravascular red blood cells were present occasionally. Immunohistochemistry performed in eight specimens showed variable endothelial cell reactivity for CD31 (7 of 8), CD34 (7 of 7), and factor VIII-related antigen (4 of 6). A smooth muscle cell layer was observed focally around the vascular spaces in six lesions. Benign lymphangioendothelioma (acquired progressive lymphangioma) is an uncommon benign lesion that, in view of major differences in treatment and prognosis, should be distinguished from well-differentiated angiosarcoma and Kaposi's sarcoma, especially the patch stage and lymphangioma-like variants of the latter.

Lymphangioma-like Kaposi's sarcoma: etiology and literature review

Much confusion surrounds a rare and occasionally described variant of Kaposi's sarcoma (KS) known as lymphangioma-like or bullous KS. We describe the typical clinical and histologic features and elucidate the etiologic cell in lymphangioma-like KS. A computer-based review of the English-language literature was performed. Routine histologic and immunoperoxidase techniques were performed on formalin-fixed tissue. Immunoperoxidase staining for anti-CD31, anti-CD34, and anti-factor VIII-related antigen suggests that the etiologic cell of origin is the vascular endothelial cell. Lymphangioma-like KS has been described for more than a century and given various names. Dilated vascular spaces correlate with the clinically bullous lesions, which are veritable KS and not a secondary reaction to it.