JAK2 R683S Mutation Resulting in Dual Diagnoses of Chronic Eosinophilic Leukemia and Myelodysplastic/Myeloproliferative Overlap Syndrome

A 66-year-old male presented with hypereosinophilia, thrombocytosis, extensive thrombosis refractory to direct oral anticoagulant therapy, and evidence of end-organ damage, including rash, splenic infarcts, and pulmonary infiltrates. Bone marrow biopsy revealed myeloid malignancy consistent with both chronic eosinophilic leukemia and myelodysplastic/myeloproliferative neoplasms (MDS/MPN) with SF3B1 mutation and thrombocytosis. Next-generation sequencing of the patient's eosinophils and neutrophil compartments revealed pathologic variants in EZH2 and SF3B1 in addition to a noncanonical JAK2 R683S mutation that has not been previously described in myeloproliferative disorders or other chronic myeloid neoplasms. These mutations were not present in the patient's lymphoid cell fraction, suggesting that the hematopoietic malignancy arose in a myeloid-committed progenitor cell. Based on this case and previous work from our group, we propose that noncanonical JAK2 mutations may permit signal transduction that biases toward eosinophilic differentiation in chronic myeloid neoplasms. Although the patient's blood counts initially responded to ruxolitinib and hydroxyurea, the response was not durable. Early referral for allogenic bone marrow transplant appears necessary to prevent long-term complications and disease progression in myeloid neoplasms with clonal hypereosinophilia driven by noncanonical JAK2 mutations.

Merkel Cell Carcinoma: Current Issues Regarding Diagnosis, Management, and Emerging Treatment Strategies

Merkel cell carcinoma (MCC) is a rare but aggressive cutaneous tumor with a predilection for the head and neck of elderly Caucasian patients. Although much less common than melanoma, MCC has higher rates of sentinel lymph node involvement, local and regional recurrences, and mortality. The majority of MCC cases have been linked to the relatively newly discovered Merkel cell polyomavirus, which is a ubiquitous constituent of the skin flora. Recent discoveries regarding viral integration and carcinogenesis and the immunologic features of MCC have expanded the understanding of MCC. These discoveries have led to the development and application of emerging therapies such as somatostatin analogs, immune checkpoint inhibition, adoptive cell therapy, and other exciting possibilities for targeted therapy.

Benign melanocytic lymph node deposits in the setting of giant congenital melanocytic nevi: the large congenital nodal nevus

BACKGROUND

Benign melanocytic rests are a frequent finding in superficial lymph nodes removed during sentinel lymph node biopsies for melanoma. Whereas the histopathology of these deposits is well understood, very little is known regarding melanocytic lymph node deposits in the setting of giant congenital melanocytic nevi.

METHODS

We analyzed lymph nodes removed from the drainage basin of giant congenital melanocytic nevi in three patients who had developed melanoma within their giant congenital nevi.

RESULTS

Two of three patients showed widespread, capsular and parenchymal melanocytic deposits in multiple nodes (9 of 11 nodes in one patient and 6 of 8 in the other). Melanocytes were small, non-mitotically active and resembled those in the associated giant congenital melanocytic nevus. Melanocytes were arranged singly and in small nests ∼0.05 mm in diameter, with some larger sheets up to 1 mm. Nodal melanocytes stained for Melan A and S100 on immunohistochemical evaluation, but showed negative or minimal HMB-45 reactivity.

CONCLUSIONS

Evaluation of lymph nodes in the setting of giant congenital melanocytic nevi is complicated by the presence of often numerous, parenchymal melanocytic nevic deposits. Bland cytology and minimal or absent HMB-45 staining may be helpful in differentiating these nodal melanocytic nevi from metastatic melanoma. We term this phenomena large congenital nodal nevus.

Resident Rounds: Part III - Case Report: Argyria – A Case of Blue-Gray Skin

Argyria is an uncommon blue-gray pigmentation of the skin (increased in sun-exposed areas), nail unit, and mucous membranes caused by prolonged silver exposure. Commonly occurs in the setting of occupational exposure, silver-containing medications, or systemic absorption from use of silver sulfadiazine on extensive burns/wounds. Recently, there appears to be an increase in the practice of colloidal silver ingestion given the popularity and easy availability of alternative medicines and dietary supplements containing various silver-containing compounds. We report a case of argyria in a 72-year-old male following ingestion of colloidal silver as a supplement for over 10 years. He had a diffuse, blue-gray discoloration of his face and nails. A skin biopsy was performed and histology supported the clinical diagnosis of argyria. Our objective is to increase the awareness for this rare dermatologic entity by highlighting the clinical and histological features through a case report. Dermatologists should warn patients in regards to the use of colloidal silver for alternative health practices.

Orf parapoxvirus infection from a cat scratch

A 53-year-old woman presented with an enlarging, tender, ulcerated nodule on her dorsal hand after being scratched by a stray kitten. Histology was consistent with orf parapoxvirus infection. The lesion resolved without scarring after several weeks of treatment with imiquimod 5 percent cream. Orf is a zoonosis transmitted to humans from sheep and goats by direct contact or by fomites. Transmission by cat scratch has not been previously described in the literature.

Severe retention hyperkeratosis occurring with Susac syndrome

A 50-year-old woman presented for asymptomatic yellow hyperkeratotic plaques limited to her face. The plaques reportedly arose over the six months prior to her clinic visit. She was healthy prior to the diagnosis of Susac syndrome (retinocochleocerebral vasculopathy) two years before. A punch biopsy was performed and revealed retention hyperkeratosis. Retention hyperkeratosis is a benign and commonly seen skin condition in primary care and dermatology. Retention hyperkeratosis occurs when there is abnormality of routine desquamation that can be associated with poor hygeine. It can be associated with acne or ichthyosis. Our case of retention hyperkeratosis is unique because of the profound presentation in a setting of an untreated psychiatric condition. Treatment consisted of daily topical exfoliative care. We also encouraged her family members to help her to seek medical attention for Susac syndrome.

The role of vulvar skin biopsy in the evaluation of chronic vulvar pain

Sixty-one percent of refractory vulvodynia patients evaluated in a tertiary care vulvovaginal clinic had clinically relevant dermatoses based on dermatopathologist-analyzed vulvar biopsy including: lichen sclerosus, allergic/irritant dermatitis, lichen planus, and other inflammatory or neoplastic dermatoses. Given the frequency of dermatologic disease, vulvar biopsy and analysis by a dermatopathologist are recommended in patients with vulvodynia.

Lipodystrophia centrifugalis abdominalis infantilis in a Caucasian girl: report of a case with perieccrine inflammation

Lipodystrophia centrifugalis abdominalis infantilis (LCAI) is a rare, self-limiting disease typically affecting Asian children around the age of three. In classic cases, patients present with a hypopigmented patch with central atrophy and an erythematous border in the groin area. We present a case of LCAI affecting a female Caucasian toddler that shows striking perieccrine inflammation, a finding not previously reported in this entity. LCAI has been rarely reported in Caucasian children; as a result, there is sparse literature on the histopathological findings in this subset. This case illustrates how significant deep dermal and perieccrine inflammation can be seen in this condition, thus broadening the histopathological spectrum of this disorder.

Pseudoxanthoma elasticum-like fibers in the inflamed skin of patients without pseudoxanthoma elasticum

BACKGROUND

Pseudoxanthoma elasticum (PXE) is an inherited disorder leading to characteristic calcified elastic fibers in skin, eyes and vasculature. PXE-like fibers have not been described in inflammatory skin disease in the absence of other signs of PXE.

METHODS

The histopathology of inflamed skin from 13 patients that contained PXE-like fibers but lacked clinical evidence of PXE were studied. Six of these and six comparison specimens from known patients with PXE were subjected to polymerase chain reaction amplification and sequencing of exons 24 and 28 of the PXE-associated gene ABCC6. This genetic analysis employed a novel assay utilizing paraffin-embedded tissue.

RESULTS

Incidental PXE-like fibers were found in patients without clinical suspicion of PXE in lesional tissue showing lipodermatosclerosis, granuloma annulare, lichen sclerosus, morphea profunda, erythema nodosum, septal panniculitis, basal cell carcinoma and fibrosing dermatitis. Two patients with PXE-like fibers but without clinical findings of PXE were heterozygous for a PXE-associated ABCC6 sequence alteration.

CONCLUSIONS

This pilot study shows elastic fibers similar to those of PXE in the lesional skin of patients with a variety of inflammatory skin diseases in the absence of clinical evidence of PXE; and some of these patients harbor changes in ABCC6.

Proliferation, apoptosis, and survivin expression in a spectrum of melanocytic nevi

BACKGROUND

Apoptosis is important for maintenance of tissue homeostasis and often dysregulated in cutaneous neoplasms. The apoptosis inhibitor survivin is expressed in melanoma and non-melanoma skin cancers and benign keratinocytic lesions. Its expression has not been studied in melanocytic nevi.

OBJECTIVE

We determined the expression pattern of survivin in benign melanocytic nevi in comparison to markers of proliferation and apoptosis.

METHODS

Six cases of each of the following melanocytic nevi were retrieved from a dermatopathology archive: compound dysplastic nevus, intradermal nevus, compound nevus, neurotized intradermal nevus, and Spitz nevus. Survivin expression was evaluated by in situ hybridization. Apoptotic and proliferation indices were calculated by counting immunoreactive cells in terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling and proliferating cell nuclear antigen immunostained sections, respectively.

RESULTS

All nevi, regardless of histologic type, expressed survivin. Compound melanocytic lesions expressed survivin in both epidermal and dermal compartments. The apoptotic rate was low for dysplastic, compound, and Spitz nevi, and apoptotic cells were not identified in any neurotized nevus. The proliferative index was highest for Spitz nevi, while all other nevi demonstrated rare positive cells.

CONCLUSIONS

Survivin is consistently expressed in benign melanocytic lesions, while apoptotic cells are rarely identified, suggesting the dysregulation of apoptotic pathways with the accumulation of cells in these neoplasms.

Fibroepithelioma of Pinkus Is a Fenestrated Trichoblastoma

Pinkus described "pre-malignant fibroepithelioma" as a proliferation that gave rise to many tiny basal cell carcinomas within each lesion. Later authors have generally considered it to be an unusual variant of basal cell carcinoma (BCC). The delineation of trichoblastoma as the general term for the benign counterpart of BCC raises the possibility that the fibroepithelioma of Pinkus (FEP) would be better classified under that rubric. To address this subject, we examined the records of 114 patients with FEP for body site, age and sex distribution, and sections from 75 lesions. All FEP examined show a blunt interface with the underlying dermis (where one could be seen), differentiation toward follicular bulbs and papillae, and large areas of cellular stroma. FEP has a slight female preponderance in contrast to BCC, which is more common in males. Unlike the common types of BCC, FEP has an overwhelming predilection for the trunk and extremities, and only 5% of tumors are set in a dermis with significant amounts of solar elastosis. Next, FEP, BCC, and FEP with BCC-like areas were stained with MIB-1 (to assess proliferation), p53 (an oncogene product), and CK20 (a Merkel cell marker) antisera. FEP shows a low level of staining for p53 and MIB-1, in contrast to conventional BCCs that over-express these markers. FEP also shows retention of Merkel cells, a characteristic of benign neoplasms with follicular germinative differentiation but not in general of BCC. The BCC-like areas in some FEP tumors reflect these staining tendencies with less striking differences. Given the contrast between FEP and BCC with respect to site of occurrence, relationship to sun damage, histopathologic features, and immunohistochemical studies, it appears that FEP more closely resembles trichoblastoma than BCC.

Proliferation, apoptosis, and survivin expression in keratinocytic neoplasms and hyperplasias

The dysregulation of apoptosis occurs in many cutaneous disease states. Several apoptosis inhibitors have been shown elevated in neoplasms and in some inflammatory conditions, but their relation to proliferative and apoptotic states has not been defined. We examined the expression of the apoptosis inhibitor survivin in a panel of keratinocytic neoplasms and hyperproliferative skin lesions using both immunohistochemistry and a newly developed in situ hybridization technique. Proliferation and apoptotic indices were also assessed by immunohistochemical staining for proliferating cell nuclear antigen and TUNEL, respectively. We found the highest rate of proliferation in verrucae and psoriasis followed by actinic keratosis, squamous and basal cell carcinoma, lichen simplex chronicus, and seborrheic keratosis; all were significantly (P < 0.05) higher than normal skin. Apoptotic rate was increased in squamous (P = 0.05) and basal cell carcinoma (P = 0.03), but not significantly different from normal skin in the other lesions tested. Survivin expression was seen in most neoplasms and hyperproliferative lesions, but not normal skin. Survivin expression was often restricted to the upper third of the epidermis in psoriasis and lichen simplex chronicus, whereas all the other lesions stained diffusely. Survivin expression appears to be a consistent feature of keratinocytic neoplasms and hyperproliferative lesions and may contribute to the formation of epidermal hyperplasia seen in all of these disease states.

Syringocystadenoma papilliferum: an unusual cutaneous lesion in a pediatric patient

We report a case of syringocystadenoma papilliferum, a rare cutaneous adnexal neoplasm, occurring synchronously in two distinct unusual locations in a 22-month-old child with lesions on the lower leg and back.

Seborrheic keratoses: A study comparing the standard cryosurgery with topical calcipotriene, topical tazarotene, and topical imiquimod

BACKGROUND

Patients with seborrheic keratoses frequently desire an effective topical therapy for seborrheic keratoses.

OBJECTIVE

To compare topical calcipotriene, topical tazarotene, and topical imiquimod with standard cryosurgery in the treatment of seborrheic keratoses.

METHODS

Fifteen patients with numerous seborrheic keratoses were enrolled in an open-label study comparing cryosurgery with topical agents. Eight separate seborrheic keratoses were selected to be treated with topical medications. One lesion was treated with cryosurgery.

RESULTS

One treatment with cryosurgery led to clinical and histological improvement of all lesions treated. Neither scarring nor recurrence resulted in cryosurgery. In seven of 15 patients, tazarotene 0.1% cream applied BID caused clinical improvement in lesions within 16 weeks.

CONCLUSION

Cryosurgery produces clinical and histological improvement of seborrheic keratoses. The result with cryosurgery was cosmetically acceptable to all patients. Responders to tazarotene cream 0.1% found it cosmetically acceptable.

Scleredema adultorum of Buschke treated with radiation

BACKGROUND

Scleredema adultorum of Buschke is an uncommon skin condition that may accompany diabetes mellitus. Current therapeutic options are poor, with only case reports and small series supporting their use.

OBSERVATION

We describe 3 patients with severe restrictive scleredema associated with type 2 diabetes mellitus who responded to radiation therapy after other treatments had failed. Angle of shoulder abduction was used as an objective measurement of improvement, while the patients rated several subjective areas, including arm range of motion, ease of performing daily tasks, ease of breathing, and neck thickening. Objective improvement tended to plateau over time but remained well above baseline. The duration of subjective improvement was variable, lasting from a few months to the end of the observation time of 2 1/2 years.

CONCLUSION

Though not consistently durable in its effect, radiation therapy appears to be a viable therapeutic option in extreme cases of this difficult-to-treat disease.

Apoptosis regulators and responses in human melanocytic and keratinocytic cells

Apoptosis in keratinocytes is required for epidermal turnover, stratum corneum formation, and removal of ultraviolet-damaged premalignant cells. Its role in melanocyte homeostasis and transformation, on the other hand, has not been defined, although apoptosis resistance is a commonly recognized feature of melanoma. We examined the expression of apoptosis regulators in melanocytes, keratinocytes, melanoma, and HaCat cells. Melanocytic cells expressed relatively high levels of Bcl-2, Bcl-X(L), Mcl-1, C-IAP-1, C-IAP-2, XIAP, Livin, and Apaf-1. The only apoptotic regulator that was differentially expressed in melanoma cells and not melanocytes was Survivin, whereas Bax was expressed in melanocytes but not in most melanoma lines. Keratinocytic cells, on the other hand, expressed high levels of FLIP and were relatively deficient in Bcl-2 family proteins. Levels of p53 were highest in HaCat cells and some of the melanoma lines, and barely detectable in melanocytes and keratinocytes. Next, susceptibility of these cells types to apoptosis induced by ultraviolet B, the tyrosine analog 4-tert-butylphenol, and cytotoxic drugs was examined. Melanocytes were relatively resistant to ultraviolet B, whereas keratinocytes were unresponsive to 4-tert-butylphenol. Melanocytes and keratinocytes were generally less susceptible than melanoma lines and HaCat cells to etoposide, cisplatin, and staurosporine. Induction of apoptosis in these cell types was generally associated with decreased levels of Mcl-1, XIAP, and Livin, and increased levels of p53, whereas levels of other apoptotic regulators were unaltered. These results provide insights into the potential roles of apoptosis in the function and transformation of epidermal melanocytes and keratinocytes.

Expression of chitin synthase genes during yeast and hyphal growth phases of Candida albicans

Chitin, the beta 1,4-linked polymer of N-acetylglucosamine, is a fibrous polysaccharide that in many yeasts helps to maintain the structure of the mother-bud junction and in filamentous fungi is often the major supporting component of the cell wall. We have previously described a Candida albicans chitin synthase, CHS1. The DNA and derived protein sequences of a second gene, CHS2, are presented and compared with previously published gene sequences. Northern blot analysis shows that strikingly different levels of synthase 1 and 2 expression occur during yeast and hyphal phases of Candida growth.

Classification of fungal chitin synthases

Comparison of the chitin synthase genes of Saccharomyces cerevisiae CHS1 and CHS2 with the Candida albicans CHS1 gene (UDP-N-acetyl-D-glucosamine:chitin 4-beta-N-acetylglucosaminyltransferase, EC 2.4.1.16) revealed two small regions of complete amino acid sequence conservation that were used to design PCR primers. Fragments homologous to chitin synthase (approximately 600 base pairs) were amplified from the genomic DNA of 14 fungal species. These fragments were sequenced, and their deduced amino acid sequences were aligned. With the exception of S. cerevisiae CHS1, the sequences fell into three distinct classes, which could represent separate functional groups. Within each class phylogenetic analysis was performed. Although not the major purpose of the investigation, this analysis tends to confirm some relationships consistent with current taxonomic groupings.

Gene transfer mechanisms among members of the genus Rhodopseudomonas

Recent studies on species of the genus Rhodopseudomonas, particularly R, capsulata and R. sphaeroides, have resulted in the development of a range of systems of genetic exchange without peer among the photosynthetic prokaryotes. In R. capsulata, systems of generalized transduction and R-prime formation have provided a detailed map of the arrangement of photosynthesis genes, while systems of conjugation and chromosome transfer in R, sphaeroides have provided a map of the location of genes involved in amino acid biosynthesis, antibiotic resistance and photosynthesis. A recent report of plasmid transformation in R. sphaeroides provides another important avenue for the analysis of genes such as those involved in photosynthesis and photochemical nitrogen fixation, through the application of DNA cloning technology. That plasmid transformation, generalized and specialized transduction, conjugation, chromosome transfer and R-prime formation do occur in Rhodopseudomonas indicates the rapid emergence of genetic and molecular biological techniques applicable to studies of these bacteria.

High-frequency chromosome transfer in Rhodopseudomonas sphaeroides promoted by broad-host-range plasmid RP1 carrying mercury transposon Tn501

Insertion of the mercury resistance transposon Tn501 into broad-host-range plasmid RP1 greatly enhanced the ability of this plasmid to promote chromosome transfer in the photosynthetic bacterium Rhodopseudomonas sphaeroides. Compared with the wild-type RP1, which produced less than 10(-8) recombinants per donor cell, RP1::Tn501 produced between 10(-3) and 10(-7) recombinants per donor cell depending upon the marker selected. Plasmid RP1::Tn501 promoted polarized transfer of the chromosome from one or perhaps two origins on the chromosome, giving rise to two linkage groups. All of the biosynthetic and antibiotic resistance genes that have been mapped, including those involved in photosynthesis, occur on one or another of these linkage groups.