Subject(s)
Carcinoma, Merkel Cell/pathology , Dermoscopy , Microscopy, Confocal , Skin Neoplasms/pathology , Humans , Male , Middle AgedABSTRACT
Diagnosis of a neutrophilic dermatosis, such as pyoderma gangrenosum (PG), often is challenging at onset because it can be impossible to distinguish clinically and histopathologically from an acute infection in an immunosuppressed patient, necessitating a detailed patient history as well as correlation pathology with microbial tissue cultures. The dermatologist's ability to distinguish a neutrophilic dermatosis from active infection is of paramount importance, as the decision to treat with surgical debridement, in addition to an antibiotic regimen, can have grave consequences in the misdiagnosed patient. We present a case of PG occurring at a chest tube site in a patient with chronic lymphocytic leukemia (CLL) and highlight the challenges and therapeutic importance of arriving at the correct diagnosis.
Subject(s)
Chest Tubes/adverse effects , Leukemia, Lymphocytic, Chronic, B-Cell , Pyoderma Gangrenosum/diagnosis , Aged, 80 and over , Diagnosis, Differential , Humans , Immunosuppressive Agents/therapeutic use , Male , Prednisone/therapeutic use , Pyoderma Gangrenosum/drug therapy , Pyoderma Gangrenosum/etiology , Triamcinolone/therapeutic useABSTRACT
CONTEXT.: Fatal dermatologic diseases and ones with high morbidity can occur in the inpatient setting. In such cases, prompt and accurate assessment of a bedside skin biopsy is required. This may be challenging for many pathologists who are not familiar with the complexity of skin pathology and skin terminology within the fields of dermatopathology and dermatology. OBJECTIVE.: To provide the pathologist with a practical, up-to-date, and "must-know" reference guide on dermatologic urgencies and emergencies from a real-world perspective, highlighting diagnostic pearls, diagnostic pitfalls, and commonly encountered practice gaps. This review will focus on key diseases with which every pathologist should be familiar, including angioinvasive fungal infections, Stevens-Johnson syndrome/toxic epidermal necrolysis, staph-scalded-skin syndrome, acute graft-versus-host disease, bullous pemphigoid, calciphylaxis, Sweet syndrome and its histiocytoid variant, pyoderma gangrenosum, and leukocytoclastic vasculitis, as well as those in their clinical and histopathologic differential. DATA SOURCES.: This review is based on peer-reviewed literature and our personal experiences with these diseases at major academic institutions, including one where a large number of stem cell transplants are performed. This review is unique as it represents collaborative expert opinion from both a dermatopathology and a dermatology standpoint. CONCLUSIONS.: This review outlines the critical role that the pathologist plays in the outcomes of patients with dermatologic urgencies and emergencies. Improved patient care will result from prompt and accurate histopathologic diagnoses as well as an open line of communication with the dermatologist.
Subject(s)
Dermatology/statistics & numerical data , Pathologists/statistics & numerical data , Skin Diseases/diagnosis , Skin/pathology , Acute Disease , Biopsy , Dermatology/standards , Graft vs Host Disease/diagnosis , Graft vs Host Disease/etiology , Hematopoietic Stem Cell Transplantation/adverse effects , Humans , Pathologists/standards , Pathology, Clinical/standards , Pathology, Clinical/statistics & numerical dataABSTRACT
Protein phosphorylation and dephosphorylation reactions play key regulatory roles in many fundamental cellular processes. Due to the large number of kinases and phosphatases in the genome, the identification of the specific enzymes responsible for a given site in a given protein is immensely challenging. However, because protein kinases and phosphatases recognize local specificity determinants within proteins, it is possible to use small peptides to study the characteristics of site-specific phosphorylation. In addition, phosphorylation usually causes retardation in gel mobility, providing an opportunity to investigate peptide phosphorylation and dephosphorylation by monitoring migration on high resolution peptide gels. In this study, we demonstrate the utility of such a technique using small peptides corresponding to cyclin-dependent kinase-1 (Cdk1)/cyclin B1 sites in two important apoptotic regulatory proteins, Bcl-xL and caspase-9. We show that the mobility of the peptides is retarded following Cdk1-mediated phosphorylation, and that peptide dephosphorylation, catalyzed either by purified phosphatase or by crude cell extracts, is readily observable by increased peptide gel mobility. Furthermore, the procedure can be conducted without the use of radioactive adenosine triphosphate (ATP), and does not require any specialized reagents or apparatus. The method can be used to identify and characterize specific kinase and phosphatases responsible for phosphorylation and dephosphorylation of specific sites in any protein of interest.
