Diagnosis of histological type of early gastric cancer by magnifying narrow-band imaging: A multicenter prospective study.

Objectives: Distinguishing undifferentiated-type from differentiated-type early gastric cancers (EGC) is crucial for determining the indication of endoscopic resection. We aimed to investigate the diagnostic performance of white-light endoscopy (WLE) and magnifying narrow-band imaging (M-NBI) for the histological type of EGC. Methods: In this multicenter prospective study, patients with histologically proven cT1 EGC, macroscopically depressed or flat type, size ≥5 mm, and without erosion/ulcer, were recruited. The diagnostic criterion of WLE for undifferentiated-type EGC was pale color. The M-NBI algorithm was created based on microsurface and microvascular patterns, and lesions with absent microsurface pattern and opened-loop microvascular patterns were diagnosed as undifferentiated-type. The center of the lesion was defined as the evaluation point and was initially evaluated by WLE, then by M-NBI, and a biopsy specimen was taken as a reference standard. The primary and key secondary endpoints were overall diagnostic accuracy and specificity, respectively. Results: In total, 167 lesions (122 differentiated-type and 45 undifferentiated-type EGCs) in 167 patients were analyzed. The overall accuracy, sensitivity, specificity, and positive likelihood ratio of WLE for undifferentiated-type cancer were 80%, 69%, 84%, and 4.4, respectively, and those of M-NBI were 82%, 53%, 93%, and 7.2, respectively. There was no significant difference in overall accuracy (p = 0.755), but specificity was significantly higher in M-NBI (p = 0.041). Conclusions: The use of M-NBI did not improve the accuracy of WLE for the diagnosis of depressed/flat undifferentiated-type EGCs but improved the specificity. It may reduce surgical overtreatment by preventing misdiagnosis of differentiated-type EGC as undifferentiated-type.

Visualization of Absorbed Lipid in the Normal Duodenal Epithelium Using Magnifying Endoscopy with Narrow-Band Imaging.

BACKGROUND: Subepithelial microvascular pattern cannot be visualized on the surface of adenoma and carcinoma by magnifying endoscopy due to a white opaque substance (WOS), which consists of minute lipid droplets accumulated in the neoplastic epithelium. AIMS: We aimed to investigate whether the WOS is visualized in the duodenum after exogenous fat loading (FL) administration in an open-label, randomized, controlled study. METHODS: The patients scheduled to undergo endoscopic therapy for gastric epithelial neoplasms were enrolled in the study. They were randomly assigned to the FL or non-FL group. An initial (before FL administration) and follow-up (after two to three weeks) endoscopic examinations were conducted to observe the duodenal mucosa using magnifying narrow-band imaging. Each patient in the FL group consumed 250 ml of Ensure H® four hours before the follow-up examination. Two experienced endoscopists determined the grade of the WOS. FL test results were judged positive for patients who showed a higher grade at the follow-up examination than at the initial examination. The rate of positive test results was compared between the two groups. RESULTS: Twenty patients (10 in the FL and 10 in the non-FL groups) were included. FL test results were positive for all 10 patients in the FL group, while they were negative for all 10 patients in the non-FL group (P < 0.001 by Fisher's exact test). CONCLUSIONS: Lipids loaded onto normal duodenal epithelium were absorbed, and the absorbed lipid droplets appeared as WOS on magnifying narrow-band imaging.

Histological subtype of gastric adenocarcinoma: two cases of mixed fundic and pyloric mucosa-type adenocarcinoma.

Adenocarcinomas with differentiation towards fundic or pyloric glands are rare histological subtypes. We herein describe two cases of new histological subtypes: mixed fundic and pyloric mucosa-type adenocarcinoma detected in Helicobacter pylori uninfected patients. The first patient was a woman in her 40s. A glossy, reddish, nodular lesion with a flat elevated whitish area was detected at the gastric fundus. When the nodular lesion was visualised with magnifying narrow-band imaging (M-NBI), an absent microvascular pattern plus an irregular microsurface pattern with a demarcation line was observed. The second patient was a woman in her 60s. A glossy, reddish, elevated lesion was detected at the gastric body. M-NBI finding was a regular microvascular pattern plus a regular microsurface pattern with a demarcation line. Histological examination of the resected specimens from both cases showed a very well- to well-differentiated adenocarcinoma which has differentiation towards the mixed fundic and pyloric mucosa. The histological and serological findings of both cases indicated the absence of H. pylori infection. The present two cases demonstrate further evidence of a new histological subtype of gastric adenocarcinoma: mixed fundic and pyloric mucosa-type adenocarcinoma, which has distinct characteristic endoscopic findings.

Antacids may increase the appearance of white opaque substance in Helicobacter pylori -eradicated gastric epithelial neoplasia.

Background and study aims White opaque substance (WOS) in gastric epithelial neoplasia is helpful for qualitative diagnosis of neoplasia. We hypothesized that WOS of neoplasia is strongly influenced by acid recovery after Helicobacter pylori eradication, similar to that of gastric intestinal metaplasia. The aim of this study was to investigate whether antacids increase the appearance of the WOS in H. pylori -eradicated neoplasia. Patients and methods A total of 38 gastric epithelial neoplasias (12 adenomas and 26 adenocarcinomas) detected after H. pylori eradication were retrospectively evaluated. Presence or absence of WOS was evaluated by magnifying endoscopy with narrow band imaging before and after antacid administration. The pH of collected gastric juice was also measured. Study endpoints were (1) prevalence of WOS in the neoplasia before and after antacid administration, and the histological difference (adenoma and adenocarcinoma); and (2) relationship between the prevalence of WOS and gastric juice pH. Results WOS prevalence increased from 0 % (0/38) to 44.8% (17/38) after antacid administration. WOS prevalence in adenomas was more significantly increased compared to that in adenocarcinomas (83.3 % vs 26.9 %, P  = 0.0077). Prevalence of WOS in gastric neoplasias was only observed at neutral levels of gastric juice pH, and WOS was not observed at strong acidic levels. Conclusions Antacid administration may increase the appearance of WOS in gastric epithelial neoplasia (especially adenomas) detected after H. pylori eradication with acid recovery.

White opaque substance visualized by magnifying narrow-band imaging is associated with intragastric acid conditions.

BACKGROUND AND STUDY AIMS: The presence of white opaque substance (WOS) is an endoscopic marker of intestinal metaplasia. Considering that the nature of WOS is absorbed lipid droplets, lipase plays an important role in the lipid absorption process and is inactivated at strong acidity. WOS may only be present in a hypochlorhydria state following Helicobacter pylori infection, and, thus, may not be highly sensitive marker, especially in H. pylori- eradicated patients. We investigated the relationship between WOS and gastric acid conditions. PATIENTS AND METHODS: A total of 501 patients were retrospectively evaluated for the presence of WOS at 2 regions of interest using magnifying narrow-band imaging. The pH level of collected gastric juice was also measured. Study end points were (1) prevalence of WOS and its relationship with gastric juice pH in 3 groups: H. pylori- uninfected , H. pylori- infected, and H. pylori -eradicated; (2) the relationship between prevalence of WOS and gastric juice pH before and after proton pump inhibitor (PPI) administration in 29 H. pylori -eradicated cases. RESULTS: Prevalence of WOS was 0 % (0 /206), 28.4 % (31/109), and 3.2 % (6/186) in the H. pylori -uninfected, H. pylori -infected, and H. pylori -eradicated groups, respectively. Mean gastric juice pH was significantly higher in WOS-positive cases than in WOS-negative cases in the H. pylori -infected and H. pylori -eradicated groups ( P  < 0.0001). Mean gastric juice pH increased from 1.1 to 6.9 after PPI administration and WOS prevalence increased from 0 % (0/29) to 45 % (13/29) of cases. CONCLUSION: The prevalence of WOS is closely associated with the neutralization of intragastric pH.

Delineation of the extent of early gastric cancer by magnifying narrow-band imaging and chromoendoscopy: a multicenter randomized controlled trial.

BACKGROUND: Accurate delineation of tumor margins is necessary for curative resection of early gastric cancer (EGC). The objective of this multicenter, randomized, controlled study was to compare the accuracy with which magnifying narrow-band imaging (M-NBI) and indigo carmine chromoendoscopy delineate EGC margins. METHODS: Patients with EGC ≥ 10 mm undergoing endoscopic or surgical resection were enrolled. The oral-side margins of the lesions were first evaluated with conventional white-light endoscopy in both groups and then delineated by either chromoendoscopy or M-NBI. Biopsies were taken from noncancerous and cancerous mucosa, each at 5 mm from the margin. Accurate delineation was judged to have been achieved when the histological findings in all biopsy samples were consistent with endoscopic diagnoses. The primary end point was the difference in rate of accurate delineation between the two techniques. RESULTS: Data on 343 patients were analyzed. The accurate delineation rate (95 % confidence interval) was 85.7 % (80.4 - 91.0) in the chromoendoscopy group (n = 168), and 88.0 % (83.2 - 92.8) in the M-NBI group (n = 175; P = 0.63). Lower third tumor location (odds ratio [OR] 2.9; P = 0.01), nonflat macroscopic type (OR 4.4; P < 0.01), and high diagnostic confidence (OR 3.6; P < 0.001) were associated with accurate delineation, whereas use of M-NBI was not (OR 1.2; P = 0.39). Even after adjustment for identified confounders, the difference in accurate delineation between the groups was not significant (OR 1.0; P = 0.82). CONCLUSIONS: M-NBI does not offer superior delineation of EGC margins compared with chromoendoscopy; the two methods appear to be clinically equivalent.

Clinical predictors of histologic type of gastric cancer.

BACKGROUND AND AIMS: Gastric cancer is classified into differentiated and undifferentiated types according to the degree of glandular differentiation. Undifferentiated-type early gastric cancer (EGC) carries a higher risk of lymph-node metastasis than differentiated type, and therefore the indication criteria for endoscopic resection differ. This study aimed to clarify the ability of clinical predictors to distinguish between differentiated-type and undifferentiated-type EGCs. METHODS: This was a post hoc study of a multicenter prospective trial carried out in 5 Japanese hospitals, including 343 patients with cT1 EGC of ≥10 mm. According to the protocol, age, sex, and endoscopic findings of cancer (diameter, location, macroscopic type, and invasion depth) were evaluated, and the final diagnosis was confirmed from resected specimens. We evaluated the associations between these clinical factors and the histologic type of cancer and calculated the ability of the factors to diagnose differentiated-type EGC. The diagnostic ability of forceps biopsy was also calculated as a reference. RESULTS: Multivariate analysis identified older age (≥72 years), male sex, larger tumor size (>30 mm), elevated type, and shallower invasion depth (cT1a) as independent significant predictors for differentiated-type EGC, with elevated type showing the highest positive likelihood ratio. The sensitivity, specificity, accuracy, and positive and negative likelihood ratios of elevated type for differentiated-type EGC were 24%, 99%, 38%, 15.7, and 0.77, respectively, compared with 96%, 86%, 95%, 7.0, and 0.04 for forceps biopsy. CONCLUSIONS: Endoscopic elevated type is a significant predictor for differentiated-type EGC and may exclude undifferentiated-type EGC without the need for forceps biopsy.

Evaluation of an e-learning system for diagnosis of gastric lesions using magnifying narrow-band imaging: a multicenter randomized controlled study.

Background and study aim Magnifying narrow-band imaging (M-NBI) is useful for the accurate diagnosis of early gastric cancer (EGC). However, acquiring skill at M-NBI diagnosis takes substantial effort. An Internet-based e-learning system to teach endoscopic diagnosis of EGC using M-NBI has been developed. This study evaluated its effectiveness. Participants and methods This study was designed as a multicenter randomized controlled trial. We recruited endoscopists as participants from all over Japan. After completing Test 1, which consisted of M-NBI images of 40 gastric lesions, participants were randomly assigned to the e-learning or non-e-learning groups. Only the e-learning group was allowed to access the e-learning system. After the e-learning period, both groups received Test 2. The analysis set was participants who scored < 80 % accuracy on Test 1. The primary end point was the difference in accuracy between Test 1 and Test 2 for the two groups. Results A total of 395 participants from 77 institutions completed Test 1 (198 in the e-learning group and 197 in the non-e-learning group). After the e-learning period, all 395 completed Test 2. The analysis sets were e-learning group: n = 184; and non-e-learning group: n = 184. The mean Test 1 score was 59.9 % for the e-learning group and 61.7 % for the non-e-learning group. The change in accuracy in Test 2 was significantly higher in the e-learning group than in the non-e-learning group (7.4 points vs. 0.14 points, respectively; P < 0.001). Conclusion This study clearly demonstrated the efficacy of the e-learning system in improving practitioners' capabilities to diagnose EGC using M-NBI.Trial registered at University Hospital Medical Information Network Clinical Trials Registry (UMIN000008569).

The nature of the white opaque substance within colorectal neoplastic epithelium as visualized by magnifying endoscopy with narrow-band imaging.

Background and study aims: We previously reported our discovery of a white opaque substance (WOS) that is opaque to endoscopic light inside the epithelium while using magnifying endoscopy (ME) to examine gastric epithelial neoplasia. Histopathologic analysis revealed that the WOS comprises minute lipid droplets (LDs) accumulated within the neoplastic epithelium. In addition, the WOS was found in colorectal epithelial neoplasia, although it was unclear whether this WOS corresponded to an accumulation of LDs, as in the stomach. Therefore, the aim of the current study was to elucidate whether the WOS observed in colorectal epithelial tumors comprises LDs. Patients and methods: A consecutive series of 40 WOS-positive and 40 WOS-negative colorectal epithelial tumors was analyzed. One biopsy specimen was taken from each neoplasm. Cryostat sections were stained with oil red O for LD, and sections after formalin-fixation for LD were immunostained with anti-adipophilin antibody. Results: The prevalence of LDs stained with oil red O in WOS-positive vs. WOS-negative lesions was 47.5 % (19/40) vs. 5 % (2/40), respectively (P < 0.001). Furthermore, the WOS coincided with the expression of adipophilin; the prevalence of LDs stained by anti-adipophilin antibody in WOS-positive vs. WOS-negative lesions was 100 % (40/40) vs. 62.5 % (25/40), respectively (P < 0.001). Conclusions: This study elucidated for the first time that endoscopically visualized WOS in colorectal epithelial neoplasia may be composed of LDs accumulated in the neoplastic epithelium.

Two cases of adenocarcinoma occurring in sporadic fundic gland polyps observed by magnifying endoscopy with narrow band imaging.

Gastric fundic gland polyps (FGPs) are common non-adenomatous gastric polyps arising from normal fundic mucosa without Helicobacter pylori (H. pylori) infection. Although systemic FGPs associated with familial adenomatous polyposis (FAP) often have dysplasia, there are few reports of dysplasia occurring in sporadic FGPs, especially when detected by magnifying endoscopy with narrow band imaging (ME-NBI). We experienced two cases of adenocarcinoma occurring in sporadic FGPs, and their ME-NBI findings were very useful for differentiating FGP with cancer from non-dysplastic FGP. A 68-year-old man and a 63-year-old woman were referred to our institution for medical checkup. H. pylori was negative in both patients. Endoscopic examination revealed a small reddish polypoid lesion on the anterior wall of the upper gastric body and several FGPs. ME-NBI showed an irregular microvascular architecture composed of closed loop- or open loop-type vascular components, plus an irregular microsurface structure composed of oval-type surface components which was different from that of FGPs. FAP was denied because of the absence of colon polyps and no familial history of FAP. Pathological diagnosis was adenocarcinoma occurring in sporadic FGP.

Histologic differentiation and mucin phenotype in white opaque substance-positive gastric neoplasias.

BACKGROUND AND STUDY AIMS: The authors previously reported that the white opaque substance (WOS) in gastric epithelial neoplasia was caused by accumulation of lipid droplets by immunohistochemical and immunoelectron microscopic studies of adipophilin, which was recently identified and validated as a marker of lipid droplets. The aim of the current study was to investigate the characteristics of the histologic differentiation and mucin phenotype in WOS-positive gastric epithelial neoplasias. PATIENTS AND METHODS: A total of 130 gastric epithelial neoplasias (45 adenomas and 85 early adenocarcinomas) from 120 patients were retrospectively evaluated. The presence or absence of WOS was evaluated by M-NBI. Lipids were examined by immunohistochemical staining for adipophilin. Tissue phenotypes were immunohistochemically classified as intestinal (I), gastrointestinal (GI), and gastric (G) using antibodies against CD10, MUC2, MUC5AC and MUC6. The histologic differentiation and mucin phenotype of WOS-positive neoplasias were characterized and examined according to adipophilin expression. RESULTS: The presence of WOS by M-NBI was correlated with histologic differences between adenoma or differentiated type adenocarcinoma and mixed type or undifferentiated type adenocarcinoma (P = 0.0153). Adipophilin was only expressed in primary adenoma and well to moderately differentiated adenocarcinoma components but not in undifferentiated components. WOS and adipophilin expression were only observed in neoplasias with I or GI phenotypes, but not in those with the G phenotype (P < 0.0001). CONCLUSIONS: WOS in gastric epithelial neoplasias might indicate differentiation into a mature histological subtype with GI or I mucin phenotype.

[A case of serous cystic neoplasm with atypical imaging results suggestive of a prismatic internal structure].

The patient was a 67-year-old man with a 39-mm unilocular pancreatic tumor detected by computed tomography (CT). Further examinations with contrast-enhanced CT, magnetic resonance imaging, endoscopic ultrasonography, and endoscopic retrograde cholangiopancreatography revealed an internal heterogeneous structure attributed to bleeding or necrosis. Consequently, we expected either a pancreatic neuroendocrine tumor or a solid pseudopapillary neoplasm and performed pancreaticoduodenectomy. Pathological examination showed that the tumor had a denatured structure with evidence of internal bleeding and cubic epithelial cysts of various sizes. The final diagnosis was a macrocystic-type serous cystic neoplasm.

Suspected de novo Hepatitis B in a Patient Receiving Anti-Tumor Necrosis Factor Alpha Therapy for the Treatment of Crohn's Disease.

We report a 45-year-old female patient who developed acute hepatic disorder during anti-tumor necrosis factor α therapy for the treatment of Crohn's disease (CD). She was diagnosed as colonic CD and placed on infliximab (IFX). She was negative for hepatitis B surface antigen at the initiation of IFX therapy, but developed acute hepatitis after the 30th administration of IFX 4 years and 1 month after the first administration. She was suspected to have had occult hepatitis B virus infection before IFX therapy, and de novo hepatitis B was considered the most likely diagnosis. Hepatitis subsided after discontinuation of anti-tumor necrosis factor α therapy and initiation of treatment with entecavir. She started to receive adalimumab to prevent relapse of CD. She has continued maintenance therapy with entecavir and adalimumab and has since been asymptomatic. As de novo hepatitis B may be fatal, virological testing for hepatitis B is essential for patients who are being considered for treatment that may weaken the immune system.

White opaque substance represents an intracytoplasmic accumulation of lipid droplets: immunohistochemical and immunoelectron microscopic investigation of 26 cases.

BACKGROUND AND AIM: White opaque substance (WOS) in gastric neoplasias is a unique finding visualized in magnifying endoscopy (ME) with narrow band imaging (NBI) and it represents intramucosal accumulation of lipid droplets using oil red O staining. METHODS: Subjects were 26 WOS-positive (13 adenomas and 13 well-differentiated adenocarcinomas) and 27 WOS-negative gastric epithelial neoplasias. We carried out immunohistochemical staining using a monoclonal antibody specific for adipophilin as a marker of lipids. Immunoelectron microscopy was used to evaluate morphology of the lipid droplets. RESULTS: Adipophilin was detected in 24 of 25 (96.0%) WOS-positive neoplasias, but it was detected in only two of 27 (7.4%) WOS-negative neoplasias. Lipid droplets were only seen in the surface epithelium in 10 of 11 (91.1%) adenomas, whereas the lipid droplets also existed in the cryptal epithelium in seven of 13 (53.8%) adenocarcinomas. Immunoelectron microscopy revealed numerous lipid droplets mainly existing in the subnuclear cytoplasm of the epithelium. The shape of the lipid droplets in adenomas was round and uniform, whereas that in adenocarcinomas was irregular. CONCLUSIONS: The present study confirmed that the presence of WOS in gastric neoplasias was dependent upon intramucosal accumulation of lipid droplets using anti-adipophilin staining. Intraepithelial distribution and morphology of the lipid droplets differed between adenoma and adenocarcinoma.

A case of splenic artery aneurysm simulating a pancreas tumor.

A 46-year-old man was admitted to our hospital for further evaluation of a hypoechogenic mass in the pancreatic body. He had no history of hypertension, pancreatitis, abdominal trauma, or portal hypertension. He had no abdominal symptoms. A contrast-enhanced CT scan demonstrated a hypodense, round shaped mass. EUS and MRI also showed it to be a pancreatic mass. Because of the tumor size of more than 30mm and the possibility of malignancy, distal pancreatectomy was performed. Microscopic findings showed the mass was the dissection of the proximal splenic artery. The true lumen of the dissecting aneurysm was occluded and the false lumen developed fusiform dilatation. Moreover, microscopic findings revealed the rupture of the false lumen complicated by pseudoaneurysm. We finally diagnosed the lesion simulating a pancreatic tumor as the pseudoaneurysm of the splenic artery.

Coexistence of Epstein-Barr virus-associated gastric carcinoma with malignant lymphoma: report of two cases.

Epstein-Barr virus (EBV)-associated gastric carcinoma (EBV-GC) is not rare, accounting for 5 to 18% of all gastric carcinomas. Recently, we encountered two cases of EBV-GC of ordinary histopathological type coexistent with malignant lymphoma. One patient was a 71-year-old Japanese man who had two lesions, one in the cardia and the other in the antrum of the stomach. The former was EBV-GC without lymphoma, and antral one was EBV-GC with diffuse large B-cell lymphoma (DLBCL). The other patient was a 49-year-old Japanese man who had received chemotherapy for pelvic DLBCL 3 years earlier. He had EBV-GC with follicular lymphoma in the fundus of the stomach. In both cases, gastric carcinomas were positive for EBV-encoded small RNA by in situ hybridization, whereas the lymphoma cells, infiltrating nonneoplastic lymphocytes, and nonneoplastic epithelial cells were negative. The present cases suggest that focal immunosuppression by adjacent gastric lymphomas might be related to the alteration of the microenvironment and development of EBV-GC.

Immunohistochemical analysis of morules in colonic neoplasms: morules are morphologically and qualitatively different from squamous metaplasia.

Morules develop in several neoplasms and have been considered as a type of squamous metaplasia despite the absence of keratinization and intercellular bridges. The objective of this study was to clarify the pathological significance of morules and to distinguish morules from squamous metaplasia in colonic neoplasms. Ten cases of morule-associated colonic neoplasms (4 adenocarcinomas, 1 adenoma with carcinoma in situ, and 5 adenomas), and 3 cases of squamous metaplasia in colonic adenocarcinoma were examined morphologically and immunohistochemically. Morules were well-defined structures composed of small, oval to short-spindled cells with bland nuclei, and frequently associated with intranuclear inclusions that were positive for biotin and biotin-binding enzymes (pyruvic acid carboxylase and propionyl CoA carboxylase). On immunohistochemical examination, morules characteristically showed nuclear overexpression of beta-catenin, cyclin D1 and p63, low Ki-67 labeling index (<1%), cytoplasmic overexpression of CD10, and no expression of cytokeratin 20. These molecules were useful for the differentiation of morules. Furthermore, p63 and 34betaE12 positivities in morules suggested that they have a basal/stem cell phenotype. Thus, morules were morphologically and qualitatively different from squamous metaplasia. We consider that morules in colonic neoplasms are cell clusters with a basal/stem cell phenotype, and have less proliferative and less invasive potential than other cancer cells.

Porocarcinoma arising in pigmented hidroacanthoma simplex.

Hidroacanthoma simplex (HAS) is a rare benign tumor that is also known as intraepidermal poroma. While there have been a few reports of HAS with malignant transformation (porocarcinoma), we report an unusual case of porocarcinoma, arising in a pigmented HAS, the latter also showing secondary amyloid deposits. An 80-year-old Japanese man presented with a cutaneous tumor on his left buttock, which had first been noticed in his childhood. The tumor consisted of flat pigmented plaque and a depigmented papule with erosion. Histologic analysis revealed many pigmented and well-defined nests within the epidermis of the flat pigmented portion. The nests were composed of cuboidal to oval and occasionally elongated, bland, basaloid cells with numerous melanin granules. In addition, there were infrequently ductal structures and small clusters of sebocytes, and abundant amyloid deposits in the upper dermis. These findings were consistent with pigmented HAS with amyloid deposition. In the depigmented portion, markedly atypical cells with occasional ductal structures and intracytoplasmic lumina extended throughout the entire thickness of the epidermis, with minimal invasion of the dermis. We considered this portion of the tumor to be a porocarcinoma. Since the two portions of the tumor were continuous, we made a final diagnosis of porocarcinoma arising in pre-existing pigmented HAS with amyloid deposition.