Xanthogranulomatous Ureteritis Mimicking Ureteral Involvement by Cancer in a Radical Cystectomy Specimen.

Xanthogranulomatous pyelonephritis is well established as a renal mass-forming inflammatory process. However, a ureteral counterpart is minimally recognized. In this article, we present a case of xanthogranulomatous ureteritis in an 81-year-old woman, mimicking ureteral involvement by cancer in a radical cystectomy specimen for invasive urothelial carcinoma. Similar to the pathogenesis of xanthogranulomatous pyelonephritis, the patient was noted to have ureteral obstruction by calculus and had urine culture positive for Klebsiella pneumoniae. To our knowledge, this is the first report of xanthogranulomatous ureteritis associated with this pathogen and the only report associated with concurrent bladder cancer. Increased pathologist and urologist awareness of xanthogranulomatous ureteritis expands the spectrum of pseudotumoral processes of the ureter.

Lower Urinary Tract Symptoms Due to Xanthoma of the Prostate After Kidney Transplantation: A Case Report.

BACKGROUND: Prostatic xanthoma is a lesion of unknown cause that is often an incidental finding in patients undergoing needle biopsy or transurethral resection. To the best of our knowledge, we report on a unique case of a pure xanthoma without benign prostatic hyperplasia of the prostate in a patient with lower urinary tract symptoms manifested after kidney transplantation. METHODS: A 62-year-old man was submitted for a kidney transplant in April 2018. He had no urinary complaints previous to the transplant. Since July 2019, he had complained of lower urinary tract symptoms. In October 2019, he had acute urinary retention being submitted to a transurethral resection of an estimated 47 g prostate. All measures of cholesterol, high-density lipoproteins (HDL), and low-density lipoproteins (LDL) were within the normal range-except triglycerides, which were mildly elevated in 2 measures. RESULTS: The pathologic examination of the resected prostate showed pure xanthoma without benign prostatic hyperplasia. A similar lesion with a xanthomatous cell component is verruciform xanthoma. It is a rare benign lesion of unknown etiology not associated with underlying disorders of lipid metabolism that has been reported in patients with bone marrow, kidney, and liver transplant. CONCLUSIONS: We report a unique case of prostate enlargement caused by pure xanthoma in a patient with renal transplant. In absence of any apparent infection, normal cholesterol measures, and appearance of symptoms after the transplant and considering the morphologic similarity with verruciform xanthoma, a lesion also reported in transplanted patients, we speculate that the pathogenesis of the lesion in this particular patient may be related to immunosuppression.

Lipid-associated rheumatologic syndromes.

Rheumatologic manifestations of hyperlipidemia and lipid-associated arthritis are rarely seen in the rheumatologist's office. On the other hand, a rheumatologist may be the clinician who identifies and initiates proper therapy for disorders related to hyperlipidemia when the musculoskeletal manifestations of these syndromes are recognized. In this article both the joint and tendon manifestations are reviewed, including the lesser known lipid liquid crystal form of arthritis. The relationship between gout and hyperuricemia is briefly discussed, as are the autoimmune manifestations of lipid-lowering therapy.

Xanthogranuloma of bone: a challenging imitator of malignancy.

Xanthogranulomatous disease of bone is exceptionally uncommon. Clinically, radiologically and pathologically, it is a great imitator of malignancy. While there are few reports on the surgical pathology of this rare entity, there is no published report on its cytopathologic characteristics. We report herein the case of a 44-year-old male who was evaluated at The Johns Hopkins Hospital for a 2.3-cm painful soft tissue mass present within the medullary canal of the distal tibia with destruction of the overlying cortex. A computed tomography-guided fine needle aspiration biopsy revealed abundant histiocytes and occasional giant cells in an inflammatory background. This was interpreted as a 'histiocyte-rich lesion,' and an excisional biopsy was recommended. Subsequent curettage was performed, and the histological material was diagnosed as 'xanthogranuloma of bone.' The rarity of xanthogranuloma of bone and its resemblance to the more common reactive and malignant bone neoplasms may present diagnostic challenges.

[Diffuse plane normolipemic xanthomatosis and necrobiotic xanthogranuloma associated with monoclonal gammopathy--determining the disease stage with PET-CT and treatment experience. Two case studies and literature review]. / Difuzní plosná normolipemická xantomatóza a nekrobiotický xantogranulom, asociované s monoklonální gamapatií--prínos PET-CT pro stanovení rozsahu nemoci a zkusenosti s lécbou. Popis dvou prípadu a prehled literatury.

UNLABELLED: Monoclonal gammopathy may manifest itself through a range of skin disorders, including plane normolipemic xanthoma and necrobiotic xanthogranuloma. The present paper describes two patients with these cutaneous symptoms. The first has extensive areas of skin affected by flat xanthomas, monoclonal gammopathy with > 10% infiltration of bone marrow with clonal plasmocytes and, according to PET-CT, unclear lymphadenopathy in the retroperitoneal area. The size of this lymphadenopathy (histologically no malignant infiltration and no confirmed infectious aetiology) has not changed significantly over a 4-year follow-up. Repeated PET-CT scans showed decrease in SUV value in this infiltration from 7.5 to 3.8. Four cycles of treatment with a combination of bortezomib, cyclophosphamide and dexamethasone brought neither reduction in monoclonal immunoglobulin nor change to skin morphology. We believe that the abdominal lymphadenopathy is associated with xanthomatosis but have been unable to confirm this unequivocally. The second patient is being followed up for more than 10 years, originally for MGUS, later for asymptomatic multiple myeloma. Last year, painful subcutaneous and cutaneous infiltrates, isolated on an upper limb and more frequent on lower limb, started to occur. These infiltrates are palpable. PET-CT imaging provided an excellent depiction of these infiltrates, showing no pathology on the head, chest and abdomen and no osteolytic foci on the skeleton. CT imaging showed clearly numerous infiltrates in the skin and subcutaneous tissue of lower limbs, particularly both shanks, reaching up to 2 cm in depth. The largest infiltrate, measuring 3.5 by 2 by 10 cm, was identified in the distal dorsal part of the right shank. PET imaging of lower limbs showed distinctly pathological accumulation in all infiltrates described above; the accumulation of glucose in the lower part of the right shank reached 10.0 SUV. CT images of lower limbs showed increased density saturated hypodermis even in the areas where there is no increased accumulation of 18 fluoroglucose. Following 40 Gy irradiation, the size of infiltrate in the radiated area decreased and their soreness ceased. CONCLUSION: PET-CT imaging offered information on extra-cutaneous signs of plane normolipemic xanthomas and provided excellent depiction of the areas of the skin and hypodermis affected by necrobiotic xanthogranuloma. Chemotherapy with cyclophosphamide, bortezomib and dexamethasone brought no reduction in monoclonal immunoglobulin concentration, and no reduction in plane normolipemic xanthomas. Radiotherapy targeted at large foci of xanthogranulomas led to partial regression and ceased infiltrate soreness.

Molluscum contagiosum involving an epidermoid cyst with xanthogranuloma-like reaction in an HIV-infected patient.

BACKGROUND: Molluscum contagiosum (MC) causes characteristic cutaneous lesions that occur mainly in children, sexually active adults, and immunocompromised individuals, especially those with human immunodeficiency virus (HIV) infection. Patients infected with HIV, particularly those with advanced disease, have an increased incidence, up to 33.3%, of MC in non-anogenital areas. MC has been rarely found to be associated with epidermoid cysts. CASE REPORT: A 44-year-old male with HIV infection presented with the complaint of a-3-month history of a tender nodule on the left neck. H&E stained sections showed a ruptured cyst, lined with squamous epithelium showing cytopathic changes of MC, and a xanthogranuloma-like inflammatory reaction with characteristic Touton-type giant cells. CONCLUSION: MC infections are common, however MC associated with epidermoid cysts is infrequent. A few cases of MC occurring in epidermoid cysts have previously been reported. We are presenting a case of MC involving an epidermoid cyst in an AIDS patient, with a unique xanthogranuloma-like reaction. Xanthogranulomatous (XG) reactions have been infrequently reported in association with other viral infections, however, poxvirus-associated XG reaction has only been observed in animals. This is the first reported case of MC-associated XG reaction in humans.

Evaluation of CD10 and procollagen 1 expression in atypical fibroxanthoma and dermatofibroma.

Atypical fibroxanthoma (AFX) (dermal pleomorphic sarcoma) remains a somewhat controversial entity. Some authors have averred that AFX is a fiction, suggesting that such lesions merely represent misclassified examples of spindled squamous cell carcinoma. In addition, the immunoperoxidase confirmation of AFX has been less than straightforward and has historically been approached as a diagnosis of exclusion because of the lack of sensitivity and specificity of available "positive" reagents. Procollagen 1 (PC1) and CD10 represent recently developed immunoperoxidase reagents that have been forwarded as useful in this setting, and we sought to characterize our experience, both to confirm the utility of these antibodies and to compare them. Our investigation included 3 separate data sets. Group 1 consisted of a retrospective review of 98 consecutive cases in which PC1 was used in the evaluation of dermatopathology specimens in routine practice during a 13-month interval. Group 2 consisted of a direct comparison of 11 AFX, 11 dermatofibroma (DF), and 7 epithelioid dermatofibroma (EDF) using the CD10 reagent on cases identified by database search. Group 3 consisted of a retrospective review of 47 cases in which CD10 was used in routine practice during a 10-month interval. Group 1 included 47 AFX, 13 carcinomas, and 6 melanomas. PC1 expression was observed in 45 of 47 AFX (96%), with a strong reaction in 78% of cases. Among a comparison group of carcinomas, 13 of 13 displayed strong keratin immunopositivity and 11 of 13 (85%) lacked PC1 expression whereas 2 showed focal weak labeling. Six of six melanomas exhibited avid S100 expression and none labeled with PC1. In group 2, strong CD10 immunoreactivity was present in 11 of 11 AFX. Similarly, 11 of 11 DFs were also positive. In contrast, 6 of 7 cases of EDF lacked CD10 expression. Group 3 included 38 AFX and 9 miscellaneous spindle cell proliferations. Of the 38 AFX, 37 (97%) labeled with CD10 and in 34 (92%) the reaction was strong. PC1 immunostaining was also completed in 34 of 38 AFX from group 3 and 27 (79%) cases showed positive labeling. Our results confirm that both PC1 and CD10 can be used as positive markers of AFX. We believe that CD10 and PC1 immunostaining can be used as a useful adjunct to supplement the diagnosis of AFX, within the context of an immunoperoxidase panel. Not surprisingly, CD10 expression is also common in DF, a benign analog of AFX, with the exception of its epithelioid variant. In direct head-to-head comparison, our experience indicates that the staining of AFX with CD10 is more avid than that observed with PC1. Lastly, out data includes over 80 examples of AFX, <5% of which showed keratin labeling. Given a general lack of keratin expression, it seems unlikely that AFX merely represents poorly differentiated squamous carcinoma.

In vitro characterization of a monoclonal IgG(kappa) from a patient with planar xanthomatosis.

OBJECTIVE: To characterize a monoclonal IgG(kappa) (MAb) from a patient with planar xanthoma that precipitated with serum lipids at reduced temperature. METHODS: The molecular weight (Mr), sensitivity to proteases, and glycosylation of the purified MAb were analyzed. The specificity of the MAb was tested by measuring cryoprecipitation with pure high- (HDL) and low-density (LDL) lipoproteins. The effect of choline, phosphocholine, and glycerol 3-phosphate on the precipitation temperature of LDL by the MAb was studied. RESULTS: The MAb was larger than normal IgG due to hyperglycosylation of the MAb light chain. It formed cryoprecipitates with pure HDL and LDL as well as the lipids extracted from these lipoproteins. Fab fragments of the MAb lowered the temperature of its precipitation with LDL. Choline, phosphocholine, and glycerol 3-phosphate also lower the precipitation temperature. CONCLUSION: This is the first human IgG reported with apparent specificity for phosphocholine antigens. Its precipitation with lipids at reduced temperature suggests that it recognizes conformations of phospholipid head groups that develop below core body temperature.

Adult-onset asthma and periocular xanthogranulomas in a patient with lymphoplasmacytic sclerosing pancreatitis.

The clinical syndrome of adult-onset asthma and periocular xanthogranulomas represents a rare systemic autoimmune disorder that has not been previously associated with autoimmune pancreatitis. Herein, we describe the case report of a 61-year-old man with the unique clinical association of adult-onset asthma, atopy, and periocular xanthogranulomas, who had previously been diagnosed with lymphoplasmacytic sclerosing pancreatitis. We have previously reported the case of a patient with lymphoplasmacytic sclerosing pancreatitis that developed postoperative inflammatory pseudotumor of the orbit. These unique, extrapancreatic, ocular manifestations of this disease add to the published observations that it is a systemic disorder with the potential for multiorgan involvement that may have a spectrum of clinical manifestations that includes adult-onset asthma and periocular xanthogranulomas.

CD99 immunoreactivity in atypical fibroxanthoma and pleomorphic malignant fibrous histiocytoma: a useful diagnostic marker.

Atypical fibroxanthoma (AFX), a benign lesion, and pleomorphic malignant fibrous histiocytoma (MFH) are thought to represent points along the same neoplastic spectrum but with different prognoses and treatments. Diagnosis based on histology and clinical parameters alone is sometimes difficult, and a reliable cost-effective immunohistochemical marker to help distinguish these lesions would be beneficial. The diagnosis of AFX or MFH was based upon published clinical and microscopic criteria. Formalin-fixed, paraffin-embedded tissues of 17 cases of AFX and 26 cases of MFH were immunostained with monoclonal antibody to CD99. For all cases, CD99 expression was scored on a four-tiered scale: negative, weak (1+), moderate (2+), or strong (3+). Two pathologists blinded to tumor diagnoses and type of immunostain evaluated each case independently. The interobserver correlation coefficient was calculated. Seventeen patients with AFX (16 males and one female; mean age = 79) and 26 patients with MFH (16 males and 10 females; mean age = 60) were included. AFX lesions were from the head and the face, mean size = 1.5 cm, and MFH lesions were from the head, the neck, the trunk, and the upper/lower extremities, mean size = 5.2 cm. The 17 cases of AFX demonstrated moderate or strong (2 to 3+) immunoreactivity with CD99, compared to nine of 26 (35%) MFH cases (chi-square = 18.38; p < 0.001; interobserver correlation coefficient = 0.83). Of these, 16 of 17 (94%) AFX cases stained diffusely with CD99, while only four of 26 (15%) MFH cases stained diffusely. Control slides were adequate. Our study demonstrated that CD99 can help distinguish AFX from MFH, in addition to other immunohistochemistry as well as clinical and histologic criteria.

Verruciform xanthoma of the oral cavity: clinicopathological study relating to pathogenesis. Report of three cases.

Verruciform xanthoma is a rare condition that was first reported in the oral cavity in 1971. Its histopathology is distinctive on account of the presence of foamy histiocytes within elongated dermal papillae. Three cases of oral mucosal verruciform xanthoma were studied. Immunohistochemical staining by streptavidin-peroxidase and in situ hybridization to detect human papillomavirus (HPV types 6, 11, 16, 18) DNA and matrix metalloproteinase (MMP-2, -9) RNA were performed to investigate the pathogenesis of verruciform xanthoma. This study showed that the foam cells were strongly positive for CD68 (KP1) and vimentin. Cytokeratin, PCNA and S-100 stained focally negative in foam cells. In situ hybridization failed to detect HPV (types 6, 11, 16, 18) in any of the three cases. Based on our findings we conclude that verruciform xanthoma is most likely not a human papillomavirus-associated lesion; the foam cells, as a histological hallmark of the lesion, are most likely derived from the monocyte-macrophage lineage, and verruciform xanthoma is, at least partly, mediated by an immune mechanism. MMPs degrade basilar membrane that promotes the reciprocal induction between epithelium and mesenchyme. However, as yet unrecognized factors may play a role in the development of epithelium-mesenchyme reciprocal induction.

Necrobiotic xanthogranuloma-rapid progression under treatment with melphalan.

Necrobiotic xanthogranuloma is a systemic disease associated in most cases with monoclonal paraproteinaemia. Although the causative role of the paraproteinaemia is supposed, the pathogenesis of this disease remains unknown. We report a 65-year-old woman with a 28-year history of disseminated indurated plaques involving her face, trunk and extremities. Since 1994 an IgG kappa paraproteinaemia was present. Current biopsies showed typical histological features of necrobiotic xanthogranuloma. We treated this extraordinary widespread condition with melphalan and prednisolone. Although the serum levels of IgG kappa light chains and gamma globulins decreased, the cutaneous plaques extended rapidly in size and number, which casts doubt on the causative significance of the paraproteinaemia in the pathogenesis of necrobiotic xanthogranuloma. The paraproteinaemia in patients with necrobiotic xanthogranuloma may rather reflect a secondary phenomenon than the originating cause. Pathogenetic and therapeutical concepts based thereon that have been proposed so far should be critically reconsidered.

Tendon xanthomas in familial hypercholesterolemia are associated with a differential inflammatory response of macrophages to oxidized LDL.

Tendon xanthomas (TX) are pathognomonic lipid deposits commonly found in familial hypercholesterolemia (FH) patients. The aim of this study was to determine whether macrophages from FH patients with TX (TX+) have higher predisposition to foam cells formation after oxidized LDL (oxLDL) overload than those from FH patients without TX (TX-), and if their differential gene expression profile could explain these different phenotypes. Total RNA pools from macrophages from FH patients TX+ and TX- were analyzed using Affymetrix oligonucleotide arrays to evaluate the gene expression profile in presence and absence of oxLDL. Also, the intracellular lipid content was measured by fluorescence flow cytometry. Results of these studies suggest that macrophages from FH subjects TX+ compared to those TX- have a differential response to oxLDL, since they show higher intracellular cholesterol ester accumulation and a differential gene expression profile. The gene array data were validated by relative quantitative real-time RT-PCR and quantitative ELISA in culture media and plasma samples. FH subjects TX+ showed increased plasma tryptase, TNF-alpha, IL-8 and IL-6 concentrations. We propose that TX formation are associated with higher intracellular lipid content, and higher inflammatory response of macrophages in response to oxLDL.