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Spotted fever group rickettsiae (SFGR) represent gram-negative intracellular bacteria transmitted to human hosts through tick bites.1,2 Although Rocky Mountain spotted fever (RMSF) represents the prototypical rickettsiosis associated with SFGR, this group also includes Rickettsia parkeri. Among the SFGR, R parkeri may produce a distinct vesicular eruption preceded by an eschar. Thus, R parkeri rickettsiosis may clinically and histopathologically simulate rickettsialpox due to Rickettsia akari. Herein, we present a case of vesicular spotted fever due to R parkeri.

Background Lichenoid granulomatous dermatitis (LGD) is an uncommon reaction pattern for which clinical correlates can be difficult to establish. LGD combines vacuolar degeneration with variable types of granulomas. Objective To determine clinical correlates of LGD. Methods The laboratory information systems at the University of Florida, the Medical College of Wisconsin, and Inform Diagnostics Research Institute were queried to identify 56 cases of LGD. Cases were reviewed for information regarding eosinophils, plasma cells, deep perivascular infiltrates, granuloma subtype, parakeratosis, epidermal atrophy, psoriasiform epidermal changes, pseudoepitheliomatous hyperplasia, periadnexal inflammation, vasculitis, and red blood cell extravasation. Results The most common clinical correlates were drug eruption (39.3%, n = 22) and lichenoid keratosis (19.6%, n = 11). Tattoo reaction, postherpetic dermatitis, and scabies or postscabietic dermatitis each accounted for 7.1% (n = 4) of cases. Pigmented purpuric dermatosis and lichen striatus each accounted for 5.4% (n = 3) of cases. Dermal eosinophils (P = .005) and psoriasiform epidermal changes (P = .055) were associated with drug hypersensitivity. Perineural (P = .049) and perifollicular (P = .003) inflammation were associated with tattoo reaction and postherpetic dermatitis. Red blood cell extravasation was helpful in cases of pigmented purpuric dermatosis (P = .049). Limitations This study is limited by its retrospective nature and statistical power. Conclusion Dermal eosinophilia, psoriasiform epidermal changes, periadnexal inflammation, and red blood cell extravasation might aid in the clinical diagnosis of patients with LGD.

The number of skin biopsies has increased over the last three decades, but benchmarks based on the number of biopsies required to capture skin cancers are lacking. To determine the most common dermatopathology diagnoses, reports of all 85,785 dermatopathology specimens examined in the Department of Dermatology at the University of Florida from January 2017 to December 2017 were reviewed. 78,353 non-excisional specimens were evaluated for diagnosis. 7,432 excisional specimens consisting of basal cell carcinoma (BCC), squamous cell carcinoma (SCC), melanoma, and dysplastic nevi were evaluated for residual tumor and marginal status. The fifteen most common diagnoses accounted for 84% of all biopsies, and an additional 30 entities accounted for 12% of all biopsies. The remaining 4% of cases were composed of only 206 diagnoses. This pattern reflects current dermatology practice in the United States, wherein the 20 most commonly encountered diseases account for 85.4% of all diagnoses made by dermatologists. Among the total number of biopsies, 90.7% of specimens were neoplasms and 9.3% were inflammatory or infectious disorders. Uncommon (4%) and inflammatory or infectious (9.3%) disorders comprise a small minority of academic dermatopathology, with implications for resident and fellowship training.

Polymorphous sweat gland carcinoma (PSGC) is a rare adnexal neoplasm with characteristic variegated histopathologic findings and low-grade clinical behavior. First described in 1994, only 11 cases have been reported in the literature. It is named for the multiplicity of architectural patterns that may be present: solid, tubular, trabecular, pseudopapillary and cylindromatous. Owing to the multiple architectural patterns, the differential diagnosis is broad, including metastatic adenocarcinoma and other adnexal neoplasms with ductular differentiation. We present two new cases of PSGC and review the literature on this rare tumor.

Vitiligo and alopecia areata are two cutaneous diseases believed to be primarily autoimmune in pathogenesis. While the coexistence of the two conditions in the same patient has been well-described, reports of the two disease processes occurring in the same location are rare. We report the case of a 10-year-old male with an unremarkable past medical history who presented with a single localized area of poliosis with depigmented underlying skin on the frontal scalp. The hair in the affected area was relatively decreased in density. A punch biopsy of the depigmented patch demonstrated features consistent with both vitiligo and alopecia areata. The decreased number of large hair follicles and a focal peribulbar lymphocytic infiltrate around an anagen follicle were suggestive of alopecia areata. A panel of melanocyte-specific stains revealed absent melanocytes in the epidermis, consistent with vitiligo. Loss of microphthalmia-associated transcription factor-positive root sheath cells was seen, suggestive of loss of melanocyte stem cells. The combination of clinical and histopathologic findings supports the theory of a common pathogenesis of alopecia areata and vitiligo.

Adult Onset Still’s Disease (AOSD) is a systemic inflammatory disorder that can be associated with hemophagocytic lymphohistiocytosis (HLH), a rare but potentially fatal disease of overactive histiocytes and lymphocytes. We present a unique case of AOSD complicated byMycoplasma pneumoniainfection and HLH. A 28-year-old female developed joint pains followed by a diffuse, erythematous, pruritic skin rash that quickly spread throughout the body. The patient deteriorated and developed fever, chills, cough, and dyspnea and had to be intubated. She had hypoalbuminemia, elevated liver enzymes, a very high serum ferritin level, positive anti-Mycoplasma pneumoniaIgG and IgM antibodies, and normal rheumatoid factor and anti-nuclear antibodies. The chest X-ray showed diffuse bilateral infiltrates. Bone marrow biopsy revealed hemophagocytosis. The patient was treated with azithromycin, methylprednisolone, and anakinra and was discharged home on cyclosporine and prednisone. This case highlights that patients can develop features of both AOSD and HLH at the beginning of the disease and early diagnosis and treatment increase the likelihood of recovery.

Vitiligo and alopecia areata are two cutaneous diseases believed to be primarily autoimmune in pathogenesis. While the coexistence of the two conditions in the same patient has been well-described, reports of the two disease processes occurring in the same location are rare. We report the case of a 10-year-old male with an unremarkable past medical history who presented with a single localized area of poliosis with depigmented underlying skin on the frontal scalp. The hair in the affected area was relatively decreased in density. A punch biopsy of the depigmented patch demonstrated features consistent with both vitiligo and alopecia areata. The decreased number of large hair follicles and a focal peribulbar lymphocytic infiltrate around an anagen follicle were suggestive of alopecia areata. A panel of melanocyte-specific stains revealed absent melanocytes in the epidermis, consistent with vitiligo. Loss of microphthalmia-associated transcription factor-positive root sheath cells was seen, suggestive of loss of melanocyte stem cells. The combination of clinical and histopathologic findings supports the theory of a common pathogenesis of alopecia areata and vitiligo.

Background: Although pathology informatics (PI) is essential to modern pathology practice, the field is often poorly understood. Pathologists who have received little to no exposure to informatics, either in training or in practice, may not recognize the roles that informatics serves in pathology. The purpose of this study was to characterize perceptions of PI by noninformatics-oriented pathologists and to do so at two large centers with differing informatics environments. Methods: Pathology trainees and staff at Cleveland Clinic (CC) and Massachusetts General Hospital (MGH) were surveyed. At MGH, pathology department leadership has promoted a pervasive informatics presence through practice, training, and research. At CC, PI efforts focus on production systems that serve a multi-site integrated health system and a reference laboratory, and on the development of applications oriented to department operations. The survey assessed perceived definition of PI, interest in PI, and perceived utility of PI. Results: The survey was completed by 107 noninformatics-oriented pathologists and trainees. A majority viewed informatics positively. Except among MGH trainees, confusion of PI with information technology (IT) and help desk services was prominent, even in those who indicated they understood informatics. Attendings and trainees indicated desire to learn more about PI. While most acknowledged that having some level of PI knowledge would be professionally useful and advantageous, only a minority plan to utilize it. Conclusions: Informatics is viewed positively by the majority of noninformatics pathologists at two large centers with differing informatics orientations. Differences in departmental informatics culture can be attributed to the varying perceptions of PI by different individuals. Incorrect perceptions exist, such as conflating PI with IT and help desk services, even among those who claim to understand PI. Further efforts by the PI community could address such misperceptions, which could help enable a better understanding of what PI is and is not, and potentially lead to increased acceptance by non-informaticist pathologists.