The Pitfall of White Blood Cell Cystine Measurement to Diagnose Juvenile Cystinosis

Cystinosis is an autosomal recessive lysosomal storage disease, caused by mutations in the CTNS gene, resulting in multi-organ cystine accumulation. Three forms of cystinosis are distinguished: infantile and juvenile nephropathic cystinosis affecting kidneys and other organs such as the eyes, endocrine system, muscles, and brain, and adult ocular cystinosis affecting only the eyes. Currently, elevated white blood cell (WBC) cystine content is the gold standard for the diagnosis of cystinosis. We present a patient with proteinuria at adolescent age and corneal cystine crystals, but only slightly elevated WBC cystine levels (1.31 ½ cystine/mg protein), precluding the diagnosis of nephropathic cystinosis. We demonstrate increased levels of cystine in skin fibroblasts and urine-derived kidney cells (proximal tubular epithelial cells and podocytes), that were higher than the values observed in the WBC and healthy control. CTNS gene analysis shows the presence of a homozygous missense mutation (c.590 A > G; p.Asn177Ser), previously described in the Arab population. Our observation underlines that low WBC cystine levels can be observed in patients with juvenile cystinosis, which may delay the diagnosis and timely administration of cysteamine. In such patients, the diagnosis can be confirmed by cystine measurement in slow-dividing cells and by molecular analysis of the CTNS gene.

Mucormycosis and Cryptococcosis with Gastrointestinal Involvement in a Patient with Poorly Managed Diabetes

Mucormycosis and cryptococcosis are invasive fungal infections that mostly infect immunocompromised patients and are associated with high mortality rates. Here, we report a case of a 54-year-old male with poorly controlled diabetes mellitus who was initially admitted with a complaint of right frontal headache and vomiting for 5 days. The patient was found to have paranasal sinuses mucormycosis, and later developed gastrointestinal cryptococcosis. A multidisciplinary approach and early management are important to avoid any delay in managing these life-threatening infections. To the best of the authors' knowledge, this is the first case reporting concurrent invasive fungal infections in a patient.

Brunner's glands hamartoma with pylorus obstruction: a case report and review of literature

Proliferative lesions of the Brunner’s glands are uncommonly encountered lesions of the small intestine, originating from the deeply seated mucosal and submucosal Brunner’s glands, mainly in the duodenum. The vast majorities of these lesions are benign and include Brunner’s glands hyperplasia (adenomas/nodules) and hamartomas. The etiology and pathogenesis of these lesions are not fully understood, and the diagnosis can sometimes be challenging. We report a case of Brunner’s gland hamartoma in a 57-year-old man who presented with chronic dyspepsia, hematemesis and weight loss. Endoscopic and radiological investigations show a submucosal polypoid lesion at the first part of the duodenum. Routine endoscopic biopsies demonstrated normal duodenal mucosa. The lesion considered endoscopically unresectable and was surgically resected. Frozen section examination and intraoperative consultation showed unremarkable duodenal mucosa and histologically bland Brunner’s glands.

Alport's syndrome with focal segmental glomerulosclerosis lesion - Pattern to recognize

The association between Alport's syndrome (AS) and focal segmental glomerulosclerosis (FSGS) in the same patient is complex and rarely reported. We report a case of a 42-year-old male presenting with proteinuria, microscopic hematuria, elevated serum creatinine and hypertension with unremarkable physical examination apart from obesity. The renal biopsy showed well-established FSGS pattern of injury with mild interstitial fibrosis and tubular atrophy, while the electron microscopic examination demonstrated glomerular basement membranes (GBM) changes compatible with AS. AS can be complicated by segmental glomerular scarring, which can mimic primary FSGS, while familial FSGS can result from mutations in collagen IV network of the GBM. This overlap can complicate histopathological interpretation of renal biopsy, which should be accompanied by mutational analysis for accurate diagnosis and proper therapeutic intervention.

Atypical antiglomerular basement membranes disease with nephrotic-range proteinuria, mesangial proliferation, and membranoproliferative glomerulonephritis pattern of injury

Antiglomerular basement membrane (anti-GBM) disease is an uncommon autoimmune disease characterized by the presence of IgG autoantibodies targeting the alpha-3 chain of type IV collagen. Some of the atypical forms of the disease have been described. Herein, we describe a case of atypical anti-GBM in a 27-year-old Saudi male who presented with lower limb edema, gross hematuria, elevated serum creatinine concentration, and nephrotic-range proteinuria. All serology tests were negative, except for anti-GBM which was weakly positive. Renal biopsy showed proliferative glomerulonephritis (GN) with nodular transformation of the glomerular tufts, mesangial hypercellularity (mesangial cell proliferation), segmental endocapillary hypercellularity and three incomplete cellular crescents, and recapitulating membranoproliferative GN pattern of glomerular injury. Direct immunofluorescence microscopy demonstrated diffuse, intense linear positivity for IgG and Kappa and Lambda light chains, and compatible with anti-GBM disease. The patient was treated with cyclophosphamide and corticosteroids in addition to therapeutic plasma exchange which resulted in mild improvement in renal function over a period of six weeks. We emphasize the importance of recognition of atypical pathological and serological patterns of anti-GBM disease, which is crucial for proper and early diagnosis and possibly improved clinical outcome and we highlight the importance of clinicopathological correlation in cases with atypical clinical and pathological presentations.

Testosterone- and Cortisol-secreting Oncocytic Adrenocortical Adenoma in the Pediatric Age-group

Oncocytic tumors are epithelial neoplasms that occur in various organs, including adrenal glands. Oncocytic adrenocortical adenomas and carcinomas are uncommon but well-known pathological entities in adults. However, generally oncocytic tumors, particularly in the adrenal glands, are very rare in the pediatric age-group. Most oncocytic adrenal tumors are not functional. We present a rare case of right-sided, functional oncocytic adrenocortical adenoma in a 5-year-old boy, who presented with clinical manifestations of precocious puberty and Cushing syndrome. Laparoscopic adrenalectomy showed a well-defined mass weighing 8.4 g and measuring 3 cm in maximum dimension. Histological examination demonstrated no features suggestive of aggressive biological behavior. The patient showed no evidence of recurrent or metastatic disease and continued to have normal serum hormonal levels 28 months following the surgery. In this report, we discuss the clinicopathological characteristics of this rare pathological entity and briefly review the literature on functional oncocytic adrenal tumors in the pediatric population.

Histopathology of Middle East respiratory syndrome coronovirus (MERS-CoV) infection - clinicopathological and ultrastructural study

Aims

The pathogenesis, viral localization and histopathological features of Middle East respiratory syndrome – coronavirus (MERS‐CoV) in humans are not described sufficiently. The aims of this study were to explore and define the spectrum of histological and ultrastructural pathological changes affecting various organs in a patient with MERS‐CoV infection and represent a base of MERS‐CoV histopathology.

Methods and results

We analysed the post‐mortem histopathological findings and investigated localisation of viral particles in the pulmonary and extrapulmonary tissue by transmission electron microscopic examination in a 33‐year‐old male patient of T cell lymphoma, who acquired MERS‐CoV infection. Tissue needle biopsies were obtained from brain, heart, lung, liver, kidney and skeletal muscle. All samples were collected within 45 min from death to reduce tissue decomposition and artefact. Histopathological examination showed necrotising pneumonia, pulmonary diffuse alveolar damage, acute kidney injury, portal and lobular hepatitis and myositis with muscle atrophic changes. The brain and heart were histologically unremarkable. Ultrastructurally, viral particles were localised in the pneumocytes, pulmonary macrophages, renal proximal tubular epithelial cells and macrophages infiltrating the skeletal muscles.

Conclusion

The results highlight the pulmonary and extrapulmonary pathological changes of MERS‐CoV infection and provide the first evidence of the viral presence in human renal tissue, which suggests tissue trophism for MERS‐CoV in kidney.

Collagenofibrotic (Collagen Type III) glomerulopathy in association with diabetic nephropathy

Collagenofìbrotic (collagen type III) glomerulopathy (CG) is a rare nonimmune-mediated glomerular disease. It is characterized by massive deposition of organized collagen type III fibers, which is localized in the mesangial and subendothelial glomerular areas and associated with increased serum levels of procollagen type III peptide. Association with systemic diseases and malignancies is extremely rare. Herein, we present a case of a nine-year-old girl, known case of type I diabetes mellitus, who presented with fever, nephrotic range proteinuria, generalized edema, and hypertension. Clinical examination did not show nail abnormalities or bone abnormalities. Renal biopsy revealed mesangial expansion and remarkable narrowing and obliteration of the glomerular capillaries by pale, amorphous material. Immunohistochemical study demonstrated diffuse linear glomerular capillary and tubular basement membrane staining for immunoglobulin G (IgG) and albumin. Ultrastructural examination identified massive mesangial and sub-endothelial deposition of dense frayed, curvilinear banded fibers with characteristic features of type III collagen. The patient was diagnosed to have combined CG and diabetic nephropathy (DN). This is the first report of CG in association with diabetic changes in renal biopsy. In this report, we describe the clinicopathological characteristics of this disease, review CG in pediatric population, and explore its association with DN.

Rare genetic variant in the CFB gene presenting as atypical hemolytic uremic syndrome and immune complex diffuse membranoproliferative glomerulonephritis, with crescents, successfully treated with eculizumab

BACKGROUND

Complement factor B gene (CFB) is an important component of the alternate pathway of complement activation that provides an active subunit that associates with C3b to form the C3 convertase, which is an essential element in complement activation. Among the complement-associated disorders, mutations and pathogenic variants in the CFB gene are relatively rare phenomena. Moreover, mutated CFB affiliation with immune-complex diffuse membranoproliferative glomerulonephritis (IC-MPGN) and atypical hemolytic uremic syndrome (aHUS) are considered a highly rare occurrence.

CASE PRESENTATION

We describe the clinical presentation, course, and pathological findings in a 7-year-old boy who has confirmed CFB heterozygous variants with pathological features compatible with IC-MPGN. Mutational analysis revealed a heterozygous variant p.Glu566Arg in exon 13 of the CFB gene. The patient did not respond to steroids and mycophenolate mofetil (MMF) therapy but responded clinically and biochemically to eculizumab treatment. This is the first case report of CFB alteration associated with IC-MPGN and aHUS that was successfully treated with eculizumab.

CONCLUSIONS

Heterozygous variants in the CFB gene can be pathogenic and associated with IC-MPGN and aHUS. Early diagnosis and prompt management can be essential in preventing end-stage renal disease. Eculizumab may provide an effective modality of treatment.

Biopsy-Proven BK Virus-Associated Nephropathy: Clinico-Pathologic Correlations

OBJECTIVES

Our objective was to study the clinico-pathologic correlations in BK virus nephropathy.

MATERIALS AND METHODS

We conducted a retrospective study of all patients with biopsy-proven polyoma (BK) virus infection. We compared their survival and renal outcomes versus BK virus-negative patients with biopsy-proven graft rejection. Histopathologic characterization by a blinded nephropathologist was performed.

RESULTS

BK nephropathy was found in 10 patients biopsied for graft dysfunction. All virus-positive patients received antithymocyte globulin induction therapy compared with only 59.3% of the BK-negative group (P = .06). The percentage of patients in the BK-negative group who received acyclovir was significantly higher than that in the BK-positive group (P = .01). After a mean observation period of 6.8 ± 3.2 years, 70% of the BK group had functioning grafts compared with 68% in the BK-negative group (P = .9) with similar 3-year graft survival in the 2 groups (80% and 90%; P = .8). Within the BK group, graft survival was better in the older group (P = .005) and in those with deceased donor kidney grafts (P = .016). Patients in the BK-negative group were heavier (mean weight of 64.3 ± 12.1 vs 46.7 ± 20.6 kg; P = .003). None of the histopathologic features studied had any effect on renal prognosis.

CONCLUSIONS

The risk factors for developing BK nephropathy were use of antithymocyte globulin, lower weight, and not using acyclovir as early prophylaxis. Within the BK nephropathy group, better graft survival was observed in deceased donor kidney recipients and in older patients. The viral load and polyoma virus nephropathy stage did not affect graft survival in this small sample study.

CK19 and CD99 Immunoexpression Profile in Goblet Cell (Mucin-Producing Neuroendocrine Tumors) and Classical Carcinoids of the Vermiform Appendix

The immunoexpression of CK19 recently has been identified as a marker of poor prognosis in pancreatic endocrine tumors and hepatocellular carcinoma. Conversely, the loss of expression of CD99 has been suggested to play a role in the tumorigenesis and dedifferentiation and is associated with poor outcome in some malignancies. The purpose of this study was to explore CK19 and CD99 immunostaining in mucin-producing neuroendocrine (goblet cell) and classical carcinoids of the appendix. Eighteen goblet cell carcinoids (GCCs) and 20 classic carcinoids were stained with CK19, CD99, and Ki-67, and these results were correlated with known pathological features of aggression: extent of invasion, mitoses, necrosis, and histological pattern. All 18 GCCs were CK19 strongly positive, whereas 16/20 classic carcinoids were also CK19 positive. Fourteen of 18 GCCs and 14/20 classic carcinoids were CD99 positive. CK19/CD99 immunoexpression did not correlate with extent of tumor invasion and mesoappendiceal extension, mitotic activity, Ki-67 labeling index, presence of extracellular mucinous pools dissecting muscle, and angiolymphatic and perineural/neural invasion. There is no difference in the immunostaining for CK19 and CD99 between GCCs and classic carcinoids, and both types of neuroendocrine tumor show the same extent of expression of both markers.

Herb-induced acute bone marrow intoxication and interstitial nephritis superimposing glomerular C1q deposition in a patient with paroxysmal nocturnal hemoglobinuria

Paroxysmal nocturnal hemoglobinuria is a rare disease of the red blood cell membrane that renders it lyzable by the complement system, leading to chronic intravascular hemolysis. Renal hemosiderosis is a well-known complication of intravascular hemolytic anemia and can lead to acute kidney injury and renal failure. The use of herbal medicine is common worldwide. The nephrotoxicity of herbal remedies can take several forms, which include acute kidney injury and acute and chronic interstitial nephritis. In addition, the use of herbal remedies can result in bone marrow toxicity and suppression. C1q nephropathy is an uncommon form of glomerular disease characterized by dominant or co-dominant glomerular immunofluorescence positivity for C1q in the absence of clinical and serological evidence of systemic lupus erythematosus, and has various clinical presentations and outcome. Here, we report a patient of undiagnosed paroxysmal nocturnal hemoglobinuria who consumed herbal medicine of unknown constituents and clinically presented with anemia and acute kidney injury. The pathological findings of bone marrow and renal biopsies that include bone marrow intoxication, severe renal hemosiderosis and acute interstitial nephritis and kidney injury, as well as co-dominant glomerular deposition of C1q, are discussed. In addition, we discuss and hypothesize the possible pathogenesis of glomerular C1q deposition in the setting of paroxysmal nocturnal hemoglobulinuria.

Salvaging of severely ruptured living-related renal allograft secondary to acute antibody mediated rejection

INTRODUCTION

Spontaneous renal allograft rupture (RAR) is a serious and potentially life-threatening complication of kidney transplantation. Debate on the management of RAR has focused on graft nephrectomy versus salvaging in cases where: the allograft rupture site is surgically manageable; the bleeding can be controlled; and/or leaving the renal allograft in situ does not compromise patient survival.

PRESENTATION OF CASE

A 45-year-old, living-related, female, kidney allograft recipient experienced RAR on the fourth day post transplantation. Surgical exploration showed 12 cm laceration along the convex border of the graft. Histologically the graft demonstrated mild acute kidney injury and linear deposition of C4d along the cortical peritubular capillaries; morphological features for violent humoral or cellular rejection were not identified. The graft was surgically salvaged with excellent clinical and biochemical improvement.

DISCUSSION

Observations arising from this case are: (1) RAR caused by rejection is still encountered in clinical practice despite effective immunosuppressive management; (2) the severity of the histopathological features of rejection does not necessarily correlate with the extent of graft rupture; and (3) salvaging the graft should be attempted whenever possible as current immunosuppression and advances in surgical techniques may have an impact on long-term graft function and survival, differing from those previously published.

CONCLUSION

With modern immunosuppression therapy and proven surgical procedures, the efficacy of salvaged renal grafts and graft survival rates may improve substantially.

Urinary bladder radiotherapy-related chondroblastic osteosarcoma: Rare case report and review of literature

Radiation-related osteosarcomas are well described malignant mesenchymal neoplasms, yet their pathogenesis is not fully understood. They are generally classified into either skeletal osteosarcomas, or their and rare soft tissue counterpart. The occurrence of osteosarcoma in the urinary bladder (UB) following radiotherapy is exceedingly rare. To the best of our knowledge, only two cases of radiation-related urinary bladder osteosarcoma have been published; we herein describe another case of an 85-year-old man who developed post radiotherapy chondroblastic osteosarcoma of the urinary bladder four years following initial surgical resection and radiotherapy for bladder urothelial carcinoma. We believe that this is the first case of radiation-related chondroblastic osteosarcoma arising in the urinary bladder. In addition, we review the literature and explore the possible histogenesis of this rare neoplasm.

Acute diffuse proliferative post-infectious glomerulonephritis in renal allograft--a case report and literature review

PVN is a well-known cause of renal allograft dysfunction and failure. The diagnosis is established by examination of tissue from the renal graft, and confirmed by immunohistochemical or in situ hybridization techniques. Electron microscopy can be utilized as an ancillary modality to identify the viral particles ultrastructurally. The tubular epithelial cells are the primary target of PV cytopathic effect; however, PV-associated glomerular changes have also been described. Immune-type electron-dense deposits in the TBMs have been described in the setting of PVN, and rarely, likewise have glomerular subepithelial hump-like deposits. Diffuse immune-mediated proliferative glomerulonephritis in the setting of PVN has not been reported before. In this report, we describe an 11-yr-old kidney transplant recipient boy who developed immune-mediated glomerulonephritis with light microscopic, immunofluorescence, and ultrastructural features compatible with acute PIGN superimposing chronic PVN, discuss this unusual association and the possible mechanisms of antigen clearance in PVN and present a literature review.

Accuracy of international guidelines for identifying significant fibrosis in hepatitis B e antigen--negative patients with chronic hepatitis

BACKGROUND & AIMS

Differing threshold levels of hepatitis B virus (HBV) DNA and alanine aminotransferase (ALT) are recommended by international guidelines for commencement of antiviral therapy. These guidelines advocate therapy for patients with significant fibrosis (METAVIR score ≥F2); we assessed the accuracy of these guideline-defined thresholds in identifying patients with ≥F2 fibrosis.

METHODS

We applied the European (European Association for the Study of the Liver [EASL] 2012), Asian-Pacific (Asian-Pacific Association for the Study of the Liver [APASL] 2012), American (American Association for the Study of Liver Diseases [AASLD] 2009), and United States Panel Algorithm (USPA 2008) criteria to 366 consecutive hepatitis B e antigen-negative patients with liver biopsy samples: EASL, ALT >laboratory-defined upper limit of normal (ULN) and HBV DNA ≥2000 IU/mL (n = 171); APASL, ALT >2-fold laboratory-defined ULN and HBV DNA ≥2000 IU/mL (n = 87); AASLD, ALT >2-fold the updated ULN (0.5-fold ULN [corresponding to ≤19 U/L] for women and 0.75-fold the ULN [corresponding to ≤30 U/L] for men) and HBV DNA ≥20,000 IU/mL (n = 53); and USPA, ALT >updated ULN (>0.5-fold ULN for women and >0.75-fold ULN for men) and HBV DNA ≥2000 IU/mL (n = 173).

RESULTS

Overall, 113 patients (30.9%) had ≥F2 fibrosis, which was more frequent among patients who fulfilled any guideline criteria (45.7% vs 17.9% for those who did not fulfill any criteria, P < .0001). In applying the EASL, AASLD, APASL, and USPA criteria, sensitivity and specificity values for detection of ≥F2 fibrosis were 45.6%, 58.5%, 56.3%, and 45.7% (P = .145) and 82.1%, 73.8%, 77.1%, and 82.4% (P = .366), respectively. The EASL criteria (area under the receiver operating characteristic [AUROC] curve, 0.66; 95% confidence interval [CI], 0.61-0.71) and USPA criteria (AUROC, 0.66; 95% CI, 0.58-0.73) performed better than APASL (AUROC, 0.64; 95% CI, 0.59-0.69; P = .421) and significantly better than the AASLD criteria (AUROC, 0.59; 95% CI, 0.54-0.64; P = .013).

CONCLUSIONS

In hepatitis B e antigen-negative patients with chronic hepatitis, the EASL, AASLD, APASL, and USPA criteria identify patients with ≥F2 fibrosis with low levels of accuracy. However, the EASL and USPA criteria are the most accurate for identification of these patients.

Left-sided congenital diaphragmatic hernia with multiple congenital cardiac anomalies, hernia sac, and microscopic hepatic heterotopia: a case report

Congenital diaphragmatic hernia is a common congenital anomaly of uncertain etiology. Its association with multiple congenital anomalies in various organs is well recognized and antenatal radiological evidence of congenital diaphragmatic hernia warrants thorough evaluation to detect other anomalies, some of which can be life threatening. Rarely, heterotopic hepatic tissue is identified in the hernia, a rare pathological finding, exhibiting more than one macroscopic and microscopic characteristics, and always associated with cardiac congenital anomalies. Herein, we report a case of left-sided microscopic heterotopic hepatic tissue in a congenital diaphragmatic hernia in an infant with multiple cardiac congenital anomalies, but with preserved pericardium.

Synchronous hepatic, mesenteric and pulmonary Epstein-Barr virus-associated smooth muscle tumors in a renal transplant recipient

Epstein-Barr virus-associated smooth muscle tumors (EBV-SMT) are distinct lesions that occur in immunocompromised patients. EBV-SMT following solid organ transplantation are rare and generally have an indolent biological behavior. Post-transplant EBV-SMT have been reported in various anatomical locations. This report describes a synchronous and multicentric development of EBV-SMT in liver, mesentery, and lung of a 33-yr-old male patient, 10 yr after a deceased allograft renal transplantation. The hepatic and mesenteric tumors were available for study. These tumors were composed of bland looking, desmin-positive, spindle-shaped cells which showed a strong nuclear staining for EBV with in situ hybridization technique. A literature review of post solid organ transplant EBV-SMT in the liver and lung, particularly regarding their pathogenesis, synchronicity and biological behavior would be provided.

Fatal Subacute Hepatic Failure in a Patient with AA-Type Amyloidosis: Case Report

Although systemic amyloidosis of amyloid-associated protein (AA) type (secondary or reactive amyloidosis) frequently involves the liver, it rarely causes clinically apparent liver disease. Mild elevation of alkaline phosphatase and hepatomegaly are the most common biochemical and clinical findings, respectively. We report a case of systemic amyloidosis of AA type, which clinically presented as subacute hepatic failure and resulted in a fatal clinical course in a 69-year-old man. To the best of our knowledge, this is the fifth case of hepatic amyloidosis of AA type that clinically presented as fatal subacute hepatic failure, an unusual clinical presentation for hepatic involvement by systemic AA-type amyloid.

Combined goblet cell carcinoid and mucinous cystadenoma of the vermiform appendix

Goblet cell carcinoid is an uncommon primary tumor of the vermiform appendix, characterized by dual endocrine and glandular differentiation. Whether goblet cell carcinoid represents a morphological variant of appendiceal classical carcinoid or a mucin-producing adenocarcinoma is a matter of conjecture. Rare cases of goblet cell carcinoid with other concomitant appendiceal epithelial neoplasms have been documented. In this report, we describe a rare case of combined appendiceal goblet cell carcinoid and mucinous cystadenoma, and discuss the possible histopathogenesis of this combination.

Squamous cell carcinoma with rhabdoid phenotype and osteoclast-like giant cells in a renal-pancreas transplant recipient

Squamous cell carcinoma (SCC) is the commonest non-melanotic malignant skin tumour encountered after solid-organ transplantation. In this setting it is associated with a worse prognosis than sun-damage-induced SCC. Rhabdoid cells and osteoclastic giant cells are infrequently seen in SCC. This case highlights the unusual occurrence of rhabdoid cells and osteoclastic giant cells in a post-transplant SCC.

Distinguishing diabetic nephropathy from other causes of glomerulosclerosis: an update

Diabetic nephropathy is a common cause of end-stage renal disease worldwide. It is characterised by diffuse or nodular glomerulosclerosis, afferent and efferent hyaline arteriolosclerosis, and tubulointerstitial fibrosis and atrophy. Diffuse and nodular diabetic glomerulosclerosis share similar histological features with other clinical conditions. Immunofluorescence and electron microscopy studies, and clinicopathological correlation are essential to differentiate diabetic nephropathy from other conditions that result in diffuse and nodular glomerulosclerosis.

Skin adnexal neoplasms--part 2: an approach to tumours of cutaneous sweat glands

Tumours of cutaneous sweat glands are uncommon, with a wide histological spectrum, complex classification and many different terms often used to describe the same tumour. Furthermore, many eccrine/apocrine lesions coexist within hamartomas or within lesions with composite/mixed differentiation. In addition to the eccrine and apocrine glands, two other skin sweat glands have recently been described: the apoeccrine and the mammary-like glands of the anogenital area. In this review (the second of two articles on skin adnexal neoplasms), common as well as important benign and malignant lesions of cutaneous sweat glands are described, and a summary for differentiating primary adnexal neoplasms from metastatic carcinoma is outlined, striving to maintain a common and acceptable terminology in this complex subject. Composite/mixed adnexal tumours are also discussed briefly.

Skin adnexal neoplasms--part 1: an approach to tumours of the pilosebaceous unit

Skin adnexal neoplasms comprise a wide spectrum of benign and malignant tumours that exhibit morphological differentiation towards one or more types of adnexal structures found in normal skin. Most adnexal neoplasms are relatively uncommonly encountered in routine practice, and pathologists can recognise a limited number of frequently encountered tumours. In this review, the first of two, the normal histology of the skin adnexal structures is reviewed, and the histological features of selected but important benign and malignant tumours and tumour-like lesions of pilosebaceous origin discussed, with emphasis on the diagnostic approach and pitfalls in histological diagnosis.

Cytokeratins 7 and 20 immunoexpression profile in goblet cell and classical carcinoids of appendix

Goblet cell carcinoid (GCC) of the vermiform appendix is an uncommon neoplasm and its histogenesis is controversial. Whether GCC represents a morphological variant of classical appendiceal carcinoid or a mucin-producing adenocarcinoma is still conjectural. Little is known about the immunohistochemical expression of cytokeratins 7 (CK7) and 20 (CK20) in appendiceal neuroendocrine tumors. In this study, we compared the expression of CK7 and CK20 in 17 cases of appendiceal GCC and 25 cases of classical carcinoid. The tumors were also evaluated for Ki-67 proliferation index, mitotic activity, tumor necrosis, extracellular pools of mucin, obvious intestinal type adenocarcinomatous foci, angiolymphatic permeation, perineural/neural infiltration, and the depth of invasion of the appendix wall. Mesoappendiceal extension was present in 14 of 17 (82.3%) cases of GCC, whereas angiolymphatic and perineural/intraaneural involvement were found in 10 of 17 (58.8%) and 14 of 17 (82.3%) cases, respectively. The mitotic count ranged from 0 per 10 high power fields to 6 per 10 high power fields, with an average of 1.4 per 10 high power fields. Necrosis was not seen in any case and pools of extravasated mucin were present in 5 of 17 (29.4%) cases. Immunohistochemically, all 17 (100%) of GCC exhibited strong and diffuse immunopositivity for CK20, whereas expression of CK7 was present in 12 cases (70.5%), ranging from 5 to 50% of tumor cells being labeled. The Ki-67 labeling index ranged from 0 to 75% and showed no correlation to mitotic activity, angiolymphatic invasion or perineural/intraneural permeation. On the other hand, 25 cases of classical carcinoid tumors were consistently negative for CK7; however, 4 cases (16%) showed immunolabeling for CK20 in 25-50% of the tumor cells. The Ki-67 labeling index in classical carcinoids ranged from 0 to 5%. This study shows that in addition to the morphological differences, GCC (CK7/CK20-positive) and classical carcinoid (CK7/CK20-negative) differ in their expression of CK7 and CK20. In addition, GCC shows the same CK7/CK20 immunoexpression as colorectal adenocarcinoma. Goblet cell carcinoid should be regarded as a crypt cell or an amphicrine carcinoma rather than a variant of carcinoid tumor, a lesion that has benign connotations.

My approach to superficial inflammatory dermatoses

Superficial inflammatory dermatoses are very common and comprise a wide, complex variety of clinical conditions. Accurate histological diagnosis, although it can sometimes be difficult to establish, is essential for clinical management. Knowledge of the microanatomy of the skin is important to recognise the variable histological patterns of inflammatory skin diseases. This article reviews the non-vesiculobullous/pustular inflammatory superficial dermatoses based on the compartmental microanatomy of the skin.

Double adenomas of the pituitary: transcription factors Pit-1, T-pit, and SF-1 identify cytogenesis and differentiation

The diagnosis of double adenomas of the pituitary can be very complex and is usually suspected on histological assessment of a specimen and confirmed by immunohistochemical and ultrastructural studies. The most commonly applied technique is currently immunohistochemical staining to localize the six pituitary hormones. Application of this technique may fail to identify double adenomas when hormone immunoreactivity is weak or absent in one or both cell populations. We examined specimens from eight patients diagnosed with double adenomas over a 15-yr period. We tested the ability to detect the difference in the two adenomas in each case using three immunostains for the pituitary transcription factors Pit-1, T-pit, and SF-1. We conclude that immunohistochemical localization of the transcription factors Pit-1, T-pit, and SF-1 accurately detects and classifies the distinct cytodifferentiation of double adenomas of the pituitary.