Utility of immunohistochemical staining with FLI1, D2-40, CD31, and CD34 in the diagnosis of acquired immunodeficiency syndrome-related and non-acquired immunodeficiency syndrome-related Kaposi sarcoma

A Case of Non-cutaneous Kaposi Sarcoma

Kaposi sarcoma is a malignancy common in patients with acquired immune deficiency syndrome (AIDS). It is a proliferative soft-tissue tumor commonly manifesting as pigmented papules and nodules on the skin. Lesions can also appear on the mucosal lining of the oropharynx and other parts of the body such as the lymph nodes. Head and neck involvement in Kaposi sarcoma is not unusual; however, laryngeal involvement is not commonly seen. We report the case of a 31-year-old gentleman, a former smoker with AIDS, who developed a mass in the throat with progressive hoarseness of voice without stridor. An elective tracheostomy was done to protect his airway before performing a direct laryngoscopy with biopsy. Histopathology examination showed neoplastic spindle cells positive for CD31, erythroblast transformation specific-related gene, and human herpesvirus 8, consistent with Kaposi sarcoma. The diagnosis of laryngeal Kaposi sarcoma in immunodeficient patients requires a high index of suspicion, especially when it occurs without classical dermatological manifestation, an interesting feature in this report.

HIV fragments detected in Kaposi sarcoma tumor cells in HIV-infected patients

Kaposi sarcoma (KS) is a malignant vascular neoplasm caused by KS-associated herpesvirus (KSHV) infection. HIV plays a major role in KS pathogenesis. KS in HIV usually produces more malignant features than classic KS. Despite the close KS-HIV relationship, no study has reported the existence of HIV in KS tissue. We used ddPCR to detect HIV and KSHV in HIV+ KS samples and classic KS control. We verified KS cell types through immunohistochemistry and applied hypersensitive in situ hybridization (ISH) to detect HIV and KSHV in tumor cells. Furthermore, we co-stained samples with ISH and immunohistochemistry to identify HIV and KSHV in specific cell types. Regarding pathological stages, the KS were nodular (58.3%), plaque (33.3%), and patch (8.3%) tumors. Moreover, ddPCR revealed HIV in 58.3% of the KS samples. ISH revealed positive Pol/Gag mRNA signals in CD34 + tumor cells from HIV + patients (95.8%). HIV signals were absent in macrophages and other inflammatory cells. Most HIV + KS cells showed scattered reactive particles of HIV and KSHV. We demonstrated that HIV could infect CD34 + tumor cells and coexist with KSHV in KS, constituting a novel finding. We hypothesized that the direct KSHV-HIV interaction at the cellular level contributes to KS oncogenesis.

HIV-Associated Cancer Biomarkers: A Requirement for Early Diagnosis

Globally, HIV/AIDS and cancer are increasingly public health problems and continue to exist as comorbidities. The sub-Saharan African region has the largest number of HIV infections. Malignancies previously associated with HIV/AIDS, also known as the AIDS-defining cancers (ADCs) have been documented to decrease, while the non-AIDS defining cancer (NADCs) are on the rise. On the other hand, cancer is a highly heterogeneous disease and precision oncology as the most effective cancer therapy is gaining attraction. Among HIV-infected individuals, the increased risk for developing cancer is due to the immune system of the patient being suppressed, frequent coinfection with oncogenic viruses and an increase in risky behavior such as poor lifestyle. The core of personalised medicine for cancer depends on the discovery and the development of biomarkers. Biomarkers are specific and highly sensitive markers that reveal information that aid in leading to the diagnosis, prognosis and therapy of the disease. This review focuses mainly on the risk assessment, diagnostic, prognostic and therapeutic role of various cancer biomarkers in HIV-positive patients. A careful selection of sensitive and specific HIV-associated cancer biomarkers is required to identify patients at most risk of tumour development, thus improving the diagnosis and prognosis of the disease.

Clinicopathologic Correlation of Kaposi Sarcoma Involving the Ocular Adnexa: Immunophenotyping of Diagnostic and Therapeutic Targets

PURPOSE

To describe the clinicopathologic characteristics and the expression of diagnostic/treatment targets in ocular adnexal Kaposi Sarcoma.

METHODS

We conducted a clinical-pathologic retrospective case series. Immunohistochemical staining for cluster of differentiation 31 (CD31), human herpesvirus-8 (HHV8), platelet-derived growth factor receptor alpha (PDGFR-A), vascular endothelial growth factor receptor-1 (VEGF), tyrosine-protein kinase Kit (c-Kit), and programmed cell death protein 1 (PD-1) were performed. Percentage of positive tumor cells was recorded for PD-1; staining intensity and distribution (H-score) were determined for the remaining stains. A Friedman non-parametric ANOVA analysis evaluated the staining.

RESULTS

The study cohort included 13 patients (age 25 to 95 years; mean 46): 7 lesions were in the eyelid, 5 in the conjunctiva, and 1 in the cornea. Nine of 11 lesions (82%) were in human immunodeficiency syndrome-positive patients (human immunodeficiency syndrome status was unknown in 2 cases). Staging included 6 plaques and 7 nodules. The mean H-scores of CD31, HHV8, c-Kit, VEGF, and PDGF-A were 8.00, 8.23, 2.77, 11.54, and 10.31, respectively. Mean PD-1 staining was 6.46%. The Friedman non-parametric ANOVA analysis showed VEGF, PDGF-A, CD31, and HHV8 differed significantly, and all differed significantly from c-Kit. Programmed cell death protein 1 staining was not significant with any clinical variable.

CONCLUSIONS

Cluster of differentiation 31 and HHV8 are helpful diagnostic adjuncts for ocular adnexal Kaposi Sarcoma. Platelet-derived growth factor receptor alpha and VEGF are promising treatment targets. Programmed cell death protein 1/PD-L1 and c-Kit are targets that are useful in several tumors; their roles in ocular adnexal Kaposi Sarcoma warrant further studies.

The Management and Prognosis of Facial and Scalp Angiosarcoma: A Retrospective Analysis of 15 Patients

BACKGROUND

Angiosarcomas are extremely aggressive malignant tumors that arise from vascular endothelial cells. The risk factors, etiology, prognostic factors, and optimal management strategies for angiosarcomas are as yet unknown.

METHODS

We retrospectively analyzed data from 15 patients who were treated in Asan Medical Center, Seoul, Republic of Korea, in the past 12 years, to assess the effect of different treatment modalities and reconstructive methods on the locoregional recurrence, metastasis, and overall survival.

RESULTS

A total of 15 patients were identified (median age at diagnosis, 72 years; range, 61-82 years). Median tumor size was 6 cm. Median follow-up was 287 days. The median overall survival was 14.96 months; a total of 13 (87%) patients had died by the end of the study.The median locoregional recurrence, metastasis, and overall survival were 7.3, 6.5, and 16.7 months, respectively. On univariate analysis, the use of adjuvant therapy after surgery (vs surgery without adjuvant therapy) was associated with delayed median time to detection of recurrence (7.9 months vs 3.1 months, respectively; P = 0.825), delayed median time to metastasis (8.7 months vs 3.1 months, respectively; P = 0.191), and better median overall survival (7.3 months vs 3.1 months, respectively; P = 0.078).The use of flap versus skin graft as a reconstructive method was associated with delayed median recurrence (8.75 vs 7.32 months, respectively; P = 0.274) and earlier median metastasis (3.75 vs 6.53 months, respectively; P = 0.365), but the same median overall survival of 16.7 months (P value: 0.945) and tumor smaller or bigger than 5 cm show earlier median time to detection of recurrence (4.17-7.32 months; P = 0.41), earlier median time to metastasis (3.75-6.53 months; P = 0.651), but better median overall survival of 18.21 versus 16.7 months, respectively (P = 0.111).

CONCLUSIONS

Multimodal treatment that combines surgery with adjuvant therapy is the best management strategy that influences survival positively in patients with angiosarcoma. The study shows that the reconstructive method does not affect the prognosis in these patients. So it is better to choose the simplest suitable resection and reconstructive method with the least complications and to avoid unnecessary procedures.

A rare case of intranodal hemorrhagic spindle cell tumor with amianthoid fibers presenting as a suspicious lump in the groin

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Hemorrhagic spindle cell tumor with amianthoid fibers is extremely rare.

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The present case adds to the very limited data available on this entity.

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The tumor in the present case reached a relatively large size and raised clinical suspicion for lymphoma.

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This tumor is a mimicker for many benign and malignant conditions.

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This tumor must be considered to avoid the misinterpretation as primary malignant spindle cell lesion or metastasis.

Introduction

Intranodal hemorrhagic spindle cell tumor with amianthoid fibers is extremely rare.

Presentation of the case

Herein, we present the case of a 58-year-old man with a 2-year history of painless left inguinal swelling. On physical examination, the mass was large, fixed, hard, and non-tender, suggesting a lymph node pathology. The mass had increased slightly in size after a short course of antibiotic treatment. The surgeon decided to perform an excisional biopsy of the left inguinal lymph node. The lesion was intraoperatively hard and suspicious for malignancy. The gross examination revealed a relatively large well-circumscribed mass with a whitish, hard, cut surface. The histomorphological and immunohistochemical findings were consistent with intranodal hemorrhagic spindle cell tumor with amianthoid fibers. There was no evidence of recurrence at 4 years post surgery.

Discussion

The present case adds to the very limited data available on this rare entity.

Conclusion

Intranodal hemorrhagic spindle cell tumor with amianthoid fibers can be a diagnostic pitfall both clinically and histopathologically. It can reach large sizes and be clinically and grossly suspicious for lymphoma. Clinicians must be made aware that such an entity exists.

Total resolution of ocular Kaposi sarcoma with different treatment approaches - a case series and review of literature

Kaposi sarcoma (KS) is an angioproliferative disease that can vary from low-grade to aggressive and lethal multicentric vascular lesions, which can involve various locations, commonly mucocutaneous, lymph nodes, and visceral organs. It can also involve unusual sites such as the eye, central or peripheral nervous system, larynx, and many other anatomical sites. We describe three cases of ocular KS, which resolved completely following different treatment modalities. All three cases were known HIV-positive individuals with low CD4 cell counts. Case 1 received pegylated doxorubicin, case 2 received local radiotherapy, and case 3 received only highly active antiretroviral therapy (HAART). All three cases responded well to their respective therapy. Ocular KS is generally responsive to treatment. Initiation of HAART can achieve a remarkable response. In large or resistant cases, other treatment modalities can be considered to achieve resolution of lesions.

A Series of Patients with Kaposi Sarcoma (Mediterranean/Classical Type): Case Presentations and Short Update on Pathogenesis and Treatment

BACKGROUND:

Kaposi’s sarcoma was first described in 1872 by Moritz Kaposi. To date, it is considered a malignant disease is originating from the endothelial cells of the lymphatic vessels believed to be infected with HHV-8. The current classification defines four major epidemiological forms of Kaposi’s sarcoma: classical, endemic, AIDS-associated, and iatrogenic.

CASE REPORT:

A 90-year-old male is presented with multiple plaques- and tumour-shaped brown-violet formations located on an erythematous-livid base in the area of both feet and both shanks. Two samples were taken from the lesions on the skin of the shanks, with histopathological examination and the subsequent immunohistochemistry showing Kaposi’s sarcoma.

CONCLUSIONS:

Kaposi sarcoma is a disease that causes difficulties both in diagnostic and therapeutic respect. The only sure way to determine the correct diagnosis is immunohistochemical staining with the anti-HHV8 antibody. Despite the wide range of systematic and local treatment options, there is still no unified algorithm and a unified strategy for the treatment of Kaposi’s sarcoma.

Role of Pattern Recognition Receptors in KSHV Infection

Kaposi’s sarcoma-associated herpesvirus or Human herpesvirus-8 (KSHV/HHV-8), an oncogenic human herpesvirus and the leading cause of cancer in HIV-infected individuals, is a major public health concern with recurring reports of epidemics on a global level. The early detection of KSHV virus and subsequent activation of the antiviral immune response by the host’s immune system are crucial to prevent KSHV infection. The host’s immune system is an evolutionary conserved system that provides the most important line of defense against invading microbial pathogens, including viruses. Viruses are initially detected by the cells of the host innate immune system, which evoke concerted antiviral responses via the secretion of interferons (IFNs) and inflammatory cytokines/chemokines for elimination of the invaders. Type I IFN and cytokine gene expression are regulated by multiple intracellular signaling pathways that are activated by germline-encoded host sensors, i.e., pattern recognition receptors (PRRs) that recognize a conserved set of ligands, known as ‘pathogen-associated molecular patterns (PAMPs)’. On the contrary, persistent and dysregulated signaling of PRRs promotes numerous tumor-causing inflammatory events in various human cancers. Being an integral component of the mammalian innate immune response and due to their constitutive activation in tumor cells, targeting PRRs appears to be an effective strategy for tumor prevention and/or treatment. Cellular PRRs are known to respond to KSHV infection, and KSHV has been shown to be armed with an array of strategies to selectively inhibit cellular PRR-based immune sensing to its benefit. In particular, KSHV has acquired specific immunomodulatory genes to effectively subvert PRR responses during the early stages of primary infection, lytic reactivation and latency, for a successful establishment of a life-long persistent infection. The current review aims to comprehensively summarize the latest advances in our knowledge of role of PRRs in KSHV infections.

Mortal allies: human immunodeficiency virus and noncommunicable diseases

PURPOSE OF REVIEW

HIV-infected individuals have improved access to antiretroviral therapy. This has resulted in a shift in causes of mortality from infectious diseases to noncommunicable diseases including cardiovascular disease, chronic kidney disease (CKD) and malignancies. This review will look at the epidemiological shift, risk factors for the development of these diseases and examine some of the supporting laboratory diagnostic testing, which may be required.

RECENT FINDINGS

Risk factors for the development of these diseases in HIV-infected patients include underlying genetic predisposition, lifestyle risk factors, chronic inflammation as a consequence of HIV infection, the presence and persistence of opportunistic infections and in some cases, highly active antiretroviral therapy, itself. Morbidity and mortality from HIV-associated conditions are increasing in low-income and middle-income countries (LMICs) with increased prevalence of HIV-associated cancers, cardiovascular disease and CKD.

SUMMARY

Management of these conditions in LMICs requires an integrated pathology solution that will enable early screening, diagnosis and monitoring.

mTOR, VEGF, PDGFR, and c-kit signaling pathway activation in Kaposi sarcoma

Kaposi sarcoma (KS) is a locally progressive, intermediate-grade vascular neoplasm with no known cure, high recurrence rates, and potential for wide dissemination. Low efficacy and high toxicity limit current therapeutic options for advanced disease. Activation of mammalian target of rapamycin (mTOR), platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), and c-kit signaling pathways has been implicated in KS pathogenesis and may suggest a role for targeted inhibitors. KS cases were retrospectively retrieved (N=274), most (90%) associated with human immunodeficiency virus. Tissue microarray slides were stained with human herpes virus-8, Friend leukemia integration 1 transcription factor, CD117 (c-kit), phospho-S6 (pS6), PDGF receptor-β, VEGF, and phospho-mTOR. Both intensity and extent of staining were scored. Multiplying these scores for each core yielded total staining H-scores. Human herpes virus-8 was positive in 87% and Friend leukemia integration 1 transcription factor in 95.7% of cases. Most were also VEGF+ (97.6%), pS6+ (95.7%), CD117+ (92.5%), and PDGFRB+ (87.4%). Approximately half (55.6%) were phospho-mTOR+. There was no significant difference in staining among patients with low (<500 cells/mm³) or preserved CD4 T-cell counts. Immunohistochemistry confirms upregulation of the mTOR, PDGF, VEGF, and c-kit pathways in a large cohort of KS samples. Of proteins tested, pS6, downstream of mTOR, demonstrated the highest proportion of strong positivity (67.1%). These results support the possibility of using targeted inhibitors in KS. Overexpression was independent of CD4 count, suggesting that even patients with low counts may be targeted therapy candidates.

Human herpesvirus 8-related diseases: Histopathologic diagnosis and disease mechanisms

The emergence of HIV/AIDS more than three decades ago led to an increased incidence of diseases caused by HHV8 co-infection, particularly Kaposi sarcoma, primary effusion lymphoma, and multicentric Castleman disease. Over time, the development of highly effective AIDS therapies has resulted in a decreased incidence of HHV8-associated entities, which are now more commonly found in patients with undiagnosed and/or untreated AIDS. Due to their rarity, some of these diseases may be difficult to recognize without appropriate clinical information. This article provides an overview of HHV8-related disorders, with a focus on their morphologic and phenotypic features, and includes a brief overview of laboratory methods used to detect HHV8. Disease mechanisms by which the HHV8 virion promotes tumorigenesis are also reviewed.

Primary pulmonary angiosarcoma: A case report

Primary sarcoma is uncommon in the lung, and primary angiosarcoma is exceedingly rare. We report a case of primary pulmonary angiosarcoma of the left lung with emphasis on its growth pattern in the lung. A 48-year-old Japanese man was admitted to our hospital because of dyspnea on exertion. He was subsequently found to have left pleural effusion. Computed tomography shows a nodular lesion measuring 7 × 4 cm in his left lung. Obstruction of the left inferior lobar bronchus was observed, and endobronchial biopsy suggested angiosarcoma. Left pneumonectomy was performed. On macroscopic examination of the cut surface, multiple nodular lesions were observed particularly in portions around branches of pulmonary artery along bronchioles. Histological examination revealed vascular channel-like structure with vague lumen formations by atypical polygonal or spindle-shaped neoplastic cells. Immunohistochemically, the neoplastic cells are positive for FLI-1, ERG, CD31 and von Willebrand factor/factor VIII-related antigen, but not CD34. Angiosarcoma is a particularly rare form of primary pulmonary tumors, and this case report describes its unique macroscopic growth pattern in the lung.

Diagnostic Immunohistochemistry in Cutaneous Neoplasia: An Update

Immunohistochemistry (IHC) is an important adjunct in the diagnosis of neoplastic skin diseases. In addition to the many established IHC markers currently in use, new markers continue to emerge, although their general acceptance and routine application requires robust validation. Here, we summarize the most well-established and commonly used biomarkers along with an array of newer ones reported in the past several decades that either demonstrate or hold high clinical promise in the field of cutaneous pathology. We also highlight recent applications of novel IHC markers in melanoma diagnosis including genetic mutation status markers [e.g. BRAF (v-raf murine sarcoma viral oncogene homolog B) and NRAS (neuroblastoma RAS viral oncogene homolog)] and an epigenetic alteration marker (e.g. 5-hydroxymethylcytosine). We specifically focus on the role of IHC in the differential diagnosis of cutaneous lesions that fall under the following categories: melanoma, epidermal tumors with an intraepidermal epitheliomatous pattern, spindle cell lesions of the dermis, small round blue cell tumors of the dermis, and cutaneous adnexal tumors. While IHC is a valuable tool in diagnostic dermatopathology, marker selection and interpretation must be highly informed by clinical context and the histologic differential diagnosis. With rapid progress in our understanding of the genetic and epigenetic mechanisms of tumorigenesis, new IHC markers will continue to emerge in the field of diagnostic dermatopathology.

D2-40 negative pyogenic granuloma-like Kaposi's sarcoma: Diagnostic features and histogenetic hypothesis of an uncommon skin tumor in HIV-negative patients

Pyogenic granuloma-like Kaposi's sarcoma (PGLKS) is a recently described skin tumor showing features both of pyogenic granuloma (PG) and Kaposi's sarcoma (KS). The differential diagnosis is often challenging. We reviewed a series of 50 PG and 23 Ks located on distal extremities with the aid of an immunohistochemical panel comprising CD34, CD31, FVIII, SMA, D2-40, HHV8. After revision, 6/50 PG lesions previously diagnosed as PG, showed positive immunostaining for LNA1-HHV8 and focal positivity for CD31 and FVIII in the endothelial cells of the proliferating vessels, with some SMA positive pericytes. D2-40, a marker of lymphatic endothelium positive in KS, stained negatively. These lesions were renamed PGLKS. Of note, in our series, PGLKS represented the only form of KS localized in the hand; all the patients were HIV-negative, older than PG patients, with a prevalence for male gender. PGLKS and PG need a different management and a follow-up is advisable for PGLKS, as for the other variants of KS. To date, D2-40 negative immunostaining has not yet been reported in PGLKS and should not lead to a misdiagnosis of PG. The morphological similarities with PG and the immunohistochemical findings, showing a defective phenotype of the neoplastic cells, suggest a histogenetic hypothesis in which D2-40 negative PGLKS could represent an early stage of HHV8 infection of a pre-existing PG, whose vessels loose progressively their blood vascular markers but have not still acquired the lymphatic ones.

Biomarkers of HIV-associated Cancer

Cancer biomarkers have provided great opportunities for improving the management of cancer patients by enhancing the efficiency of early detection, diagnosis, and efficacy of treatment. Every cell type has a unique molecular signature, referred to as biomarkers, which are identifiable characteristics such as levels or activities of a myriad of genes, proteins, or other molecular features. Biomarkers can facilitate the molecular definition of cancer, provide information about the course of cancer, and predict response to chemotherapy. They offer the hope of early detection as well as tracking disease progression and recurrence. Current progress in the characterization of molecular genetics of HIV-associated cancers may form the basis for improved patient stratification and future targeted or individualized therapies. Biomarker use for cancer staging and personalization of therapy at the time of diagnosis could improve patient care. This review focuses on the relevance of biomarkers in the most common HIV-associated malignancies, namely, Kaposi sarcoma, non-Hodgkin’s lymphoma, and invasive cervical cancer.

Diagnostic value of endothelial markers and HHV-8 staining in gastrointestinal Kaposi sarcoma and its difference in endoscopic tumor staging

AIM: To clarify the diagnostic values of hematoxylin and eosin (HE), D2-40, CD31, CD34, and HHV-8 immunohistochemical (IHC) staining in gastrointestinal Kaposi’s sarcoma (GI-KS) in relation to endoscopic tumor staging.

METHODS: Biopsy samples (n = 133) from 41 human immunodeficiency virus-infected patients were reviewed. GI-KS was defined as histologically negative for other GI diseases and as a positive clinical response to KS therapy. The receiver operating characteristic area under the curve (ROC-AUC) was compared in relation to lesion size, GI location, and macroscopic appearances on endoscopy.

RESULTS: GI-KS was confirmed in 84 lesions (81.6%). Other endoscopic findings were polyps (n = 9), inflammation (n = 4), malignant lymphoma (n = 4), and condyloma (n = 2), which mimicked GI-KS on endoscopy. ROC-AUC of HE, D2-40, blood vessel markers, and HHV-8 showed results of 0.83, 0.89, 0.80, and 0.82, respectively. For IHC staining, the ROC-AUC of D2-40 was significantly higher (P < 0.05) than that of HE staining only. In the analysis of endoscopic appearance, the ROC-AUC of HE and IHC showed a tendency toward an increase in tumor staging (e.g., small to large, patches, and polypoid to SMT appearance). D2-40 was significantly (P < 0.05) advantageous in the upper GI tract and for polypoid appearance compared with HE staining.

CONCLUSION: The diagnostic value of endothelial markers and HHV-8 staining was found to be high, and its accuracy tended to increase with endoscopic tumor staging. D2-40 will be useful for complementing HE staining in the diagnosis of GI-KS, especially in the upper GI tract and for polypoid appearance.

Predictive clinical factors in the diagnosis of gastrointestinal Kaposi's sarcoma and its endoscopic severity

BACKGROUND

The diagnosis of gastrointestinal (GI) involvement in Kaposi's sarcoma (KS) is important to make because the need for treatment depends on the extent of the disease. Moreover, severe GI lesions can cause serious complications. Endoscopy with biopsy is an extremely useful method to diagnose GI-KS. However, determining the indications for endoscopy is difficult because KS can occur without GI symptoms or cutaneous KS. This study sought to clarify predictive clinical factors for GI-KS and its severity on endoscopy.

METHODOLOGY/PRINCIPAL FINDINGS

A total of 1,027 HIV-infected patients who underwent endoscopy were analyzed. Sexual behavior, CD4 count, HIV RNA, history of highly active antiretroviral therapy (HAART), GI symptoms, and cutaneous KS were assessed. Endoscopic severity including bulky tumor, ulceration, and number of lesions were evaluated. Thirty-three patients had GI-KS and 46 patients cutaneous KS. Among the GI-KS patients, 78.8% (26/33) had no GI symptoms and 24.2% (8/33) had no cutaneous KS. Univariate analysis identified men who have sex with men (MSM), CD4 <100 cells/µL, HIV RNA ≥10,000 copies/mL, no history of HAART, and cutaneous KS were significantly associated with GI-KS. Among these factors, cutaneous KS was closely related to GI-KS on multivariable analysis. Among patients without cutaneous KS, MSM and CD4 count <100 cells/µL were the only independent clinical factors related to GI-KS. Bulky tumor was significantly associated with CD4 <100 cells/µL and large number of lesions was significantly associated with HIV-RNA ≥10,000 copies/mL.

CONCLUSIONS

To diagnose GI-KS, clinical factors need to be considered before endoscopy. The presence of GI symptoms is not useful in predicting GI-KS. MSM and CD4 count <100 cells/µL are predictive factors among patients without cutaneous KS. Caution should be exercised especially in patients with low CD4 counts or high HIV viral loads as they are more likely to develop severe GI-KS lesions.

False-Negative Results of Endoscopic Biopsy in the Diagnosis of Gastrointestinal Kaposi's Sarcoma in HIV-Infected Patients

Kaposi's sarcoma (KS) is a rare endothelial neoplasm mainly involving the skin, but it is often associated with AIDS. Diagnosis of gastrointestinal (GI) tract KS, a common site of visceral involvement in AIDS, is important, but endoscopic biopsy carries a risk of false-negative results (FNRs) due to its submucosal appearance. This study sought to determine the rate and causes of FNR for endoscopic biopsy of GI-KS lesions. Endoscopic biopsy samples of 116 GI-KS lesions were reviewed retrospectively. All GI-KS lesions were confirmed to be resolved following KS therapy. FNRs were yielded for 41 of the lesions (35.3%). Among upper and lower GI sites, the esophagus was the only site significantly associated with FNRs (P < 0.01). Small size (<10 mm) and patches found on endoscopy were significantly associated with FNRs (P < 0.05). Findings of submucosal tumor (SMT) with ulceration were significantly associated with true-positive results (P < 0.05). In conclusion, FNRs were found in 35.3% of GI-KS lesions and were especially related to the site of the esophagus and endoscopic early stage (small size or patch appearance). An SMT with ulceration may be relatively easy to diagnose on endoscopic biopsy. Caution should be exercised when performing endoscopic biopsy of these lesions in AIDS patients and evaluating the histological features.

Immunohistochemical endothelial markers: a review

A relatively large number of new endothelial markers that can assist in the diagnosis and classification of endothelial and vascular neoplasms have become available over the past few years. The expression of these markers, however, differs considerably among the various tumors. A selection of markers that have potential diagnostic utility or are of current interest among pathologists are reviewed and compared with some of the more traditional markers that have been employed in diagnostic pathology.