Triple collision tumor comprising Merkel cell carcinoma with an unusual immunophenotype, squamous cell carcinoma in situ, and basal cell carcinoma.

Merkel cell carcinoma (MCC) is a rare, aggressive primary cutaneous neuroendocrine cancer which almost always exhibits the cytokeratin (CK)20+/thyroid transcription factor (TTF)-1- immunophenotype. MCC may occur concurrently with squamous cell carcinoma, Bowen disease, and/or basal cell carcinoma (BCC), with some evidence that MCCs which occur in conjunction with other neoplasms exhibit different immunophenotypes compared to pure MCC cases. We present a case of CK20-/TTF-1+ MCC concurrent with Bowen disease and BCC, and discuss possible differences in the pathogenesis of pure vs combined MCC. We also review the literature for this unusual immunophenotype, noting that most cases occur in combined MCC.

Onset of disseminated cutaneous nodules following toe amputation in heart transplant patient.

Alternaria spp. infections are rare, but organ transplant recipients and immunosuppressed patients are particularly at risk of developing cutaneous alternariosis. Although cutaneous alternariosis is well-defined, instances of disseminated infection are exceedingly rare. We report a case of disseminated Alternaria infection in an immunocompromised patient from a primary focus of ungual phaeohyphomycosis.

miRNA expression profiles of premalignant and malignant arsenic-induced skin lesions.

Arsenic, a naturally occurring element, contaminates the drinking water of over 200 million people globally. Chronic arsenic exposure causes multiple cancers including those originating from skin, lung and bladder, and is associated with liver, kidney, and prostate cancers. Skin is the primary target organ for arsenic toxicity; chronic toxicity initially manifests as non-malignant hyperkeratoses (HK) and subsequently advances to malignant lesions, including squamous cell carcinoma (SCC) and basal cell carcinoma (BCC). In this study, we evaluate the miRNA expression profiles of premalignant (3 HK) and malignant (3 BCC and 3 SCC) skin lesions from individuals chronically exposed to high levels of arsenic (59-172 ppb) in their drinking water in West Bengal, India. The lesions were histologically complex requiring histopathologic identification of keratinocytes to be isolated for RNA analyses. Keratinocytes were harvested using Laser Capture Microdissection and miRNA expression profiles were determined using TaqMan® Array Human MiRNA A Card v2.0. Thirty-five miRNAs were differentially expressed among the three lesion types analyzed. Two miRNAs (miR-425-5p and miR-433) were induced in both BCC and SCC relative to HK indicating their association with malignancy. Two other miRNAs (miR-184 and miR-576-3p) were induced in SCC relative to both BCC and HK suggesting selective induction in tumors capable of metastasis. Six miRNAs (miR-29c, miR-381, miR-452, miR-487b, miR-494 and miR-590-5p) were selectively suppressed in BCC relative to both SCC and HK. In conclusion, the differential miRNA expression was both phenotype- and stage-related. These miRNAs are potential biomarkers and may serve as therapy targets for arsenic-induced internal tumors.

Langerhans Cell Histiocytosis Associated With Underlying Hematolymphoid Disorders in Adults: Report of 2 Cases and Review of the Literature.

Langerhans cell histiocytosis (LCH) is an uncommon disorder characterized by proliferation of abnormal LCs usually affecting children and adolescents. LCH in adults first presenting in the skin is rare. Although LCH and even LCH with a second malignancy may be more common in children, cutaneous LCH with a second hematologic malignancy has been more commonly identified in adults. The authors report 2 new cases of LCH in adult patients with underlying myelodysplasia and follicular lymphoma. The specimens were examined by routine microscopy and immunohistochemical stains for S100 protein and CD1a. Patients were elderly men with established diagnoses of follicular lymphoma and myelodysplasia, presented with follicular lesions and erythematous plaques involving intertriginous areas. Histologic examination revealed collections of mononuclear cells in upper dermis, which demonstrated strong positivity for S100 and CD1a, confirming their identity as LCs. BRAF analysis returned negative for detection of BRAF V600E mutation in both patients. The authors have recently encountered 2 cases of adult patients with skin-limited LCH predated by other lymphoproliferative disorders. The association between LCH and hematopoietic disorders may be explained by a common bone marrow precursor that is differentiating along different cell lines. Cutaneous LCH may be associated with underlying lymphoproliferative disorders and should be considered in the differential diagnosis of cutaneous eruptions in patients with hematopoietic disorders. Clinical follow-up evaluation of patients diagnosed with LCH for peripheral blood abnormalities and lymphadenopathy or "B symptoms" may be prudent in patients not already carrying a diagnosis of an underlying hematologic disorder.

Generalized linear IgA dermatosis with palmar involvement.

Linear IgA bullous dermatosis (LABD) is a sub-epidermal blistering disorder characterized by deposition of IgA along the basement membrane zone (BMZ) as detected by immunofluorescence microscopy. The diagnosis is made by clinicopathologic correlation with immunofluorescence confirmation. Differentiation from other bullous dermatoses is important because therapeutic measures differ. Prompt initiation of the appropriate therapies can have a major impact on outcomes. We present three cases with prominent palmar involvement to alert the clinician of this potential physical exam finding and to consider LABD in the right context.

New variant lymphomatoid papulosis type E preceding and coexisting with mycosis fungoides - a case report and review of the literature.

Angioinvasive (type E) lymphomatoid papulosis (LyP) is a recently described subtype of LyP presenting with eschar-like lesions that can be mistaken for aggressive forms of angiocentric cutaneous T-cell lymphoma. None of the cases of angioinvasive LyP described thus far have been associated with mycosis fungoides (MF). Herein, we describe a case of angioinvasive LyP type E coexisting with MF. The patient presented with an eschar on his chest and over time developed new nodules and large plaques with eschar formation, all of which resolved spontaneously over a period of a few weeks without intentional therapy. Biopsy revealed a CD30+ atypical inflammatory cell infiltrate with marked angiocentricity. Later, he developed erythematous annular scaly patches histologically consistent with MF. Our patient's clinical course confirms the indolent behavior characteristic of LyP despite the aggressive clinical and histologic appearance of lesions. The co-occurrence of angioinvasive LyP and MF in our patient highlights the propensity for LyP type E to coexist with MF, as is characteristic of other LyP subtypes, and supports the theory that LyP and MF are related T-cell lymphoproliferative disorders. Patients with LyP can present with large lesions exhibiting eschar formation and an atypical angiocentric/angiodestructive lymphoid infiltrate and should be spared overtreatment.

Oxalosis involving the skin: case report and literature review.

BACKGROUND: The primary hyperoxalurias are a group of rare autosomal recessive metabolic disorders associated with abnormal overproduction of serum oxalate and subsequent deposition in tissue. Most patients present at an early age with recurrent urolithiasis and renal failure. Vascular deposition of oxalate-producing skin manifestations, such as livedo reticularis, acrocyanosis, peripheral gangrene, and ulcerations, is typical of the primary hyperoxalurias. OBSERVATIONS: We present the case of a 38-year-old woman with end-stage renal disease receiving hemodialysis with progressive skin changes, including livedo reticularis, superficial eschars, and brawny, woody fibrosis of her extremities, who was clinically suspected to have calciphylaxis or nephrogenic systemic fibrosis. Cutaneous biopsy specimens revealed rectangular, birefringent, yellowish-brown, polarizable crystalline material suggestive of oxalate within the dermis, subcutis, and medium-size vessels along with areas of focal epidermal and superficial dermal necrosis. Her subsequent medical history was obtained and was suggestive of a diagnosis of primary hyperoxaluria. CONCLUSIONS: This case highlights the variability of clinical presentations in primary hyperoxaluria and that the disease can be diagnosed in adulthood. In addition, this case demonstrates that hyperoxaluria should be included in the differential diagnosis of calciphylaxis and nephrogenic systemic fibrosis.

Hydroxyurea-associated dermatomyositis-like eruption demonstrating abnormal epidermal p53 expression: a potential premalignant manifestation of chronic hydroxyurea and UV radiation exposure.

BACKGROUND: Chronic hydroxyurea therapy is associated with numerous cutaneous adverse effects. While hydroxyurea-associated nonmelanoma skin cancers are known to be associated with significant morbidity and occasional mortality, to date, dermatomyositis-like eruption has been considered a benign entity, other than its ability to mimic true dermatomyositis leading to inappropriate immunosuppression. More recently, hydroxyurea-associated squamous dysplasia has been characterized as a premalignant precursor to hydroxyurea-associated nonmelanoma skin cancers and shown to manifest abnormal p53 expression. OBSERVATIONS: An elderly woman receiving chronic hydroxyurea therapy for myelodysplasia developed a dermatomyositis-like eruption that was misdiagnosed as true dermatomyositis, leading to continuation of hydroxyurea. Years later she developed severe hydroxyurea-associated nonmelanoma skin cancers resulting in discontinuation of hydroxyurea, poor control of her myelodysplasia, and death. Re-evaluation with immunohistochemical analysis of tissue from her original dermatomyositis-like eruption revealed focal confluent nuclear expression of p53 along the lower layers of the epidermis, suggestive of a premalignant state. CONCLUSIONS: We suggest that dermatomyositis-like eruption and hydroxyurea-associated squamous dysplasia represent similar clinical manifestations of a common underlying chronic phototoxic process involving aberrant keratinocyte p53 expression mediated by hydroxyurea's antimetabolite properties and UV radiation exposure. Accordingly, we suggest that dermatomyositis-like eruption, previously considered a benign entity, may represent a premalignant precursor of hydroxyurea-associated nonmelanoma skin cancers warranting discontinuation of hydroxyurea therapy.

Cutaneous malignant peripheral nerve sheath tumors.

Cutaneous malignant peripheral nerve sheath tumors (MPNSTs) are rare entities compared with their deep soft tissue counterparts. We describe two cases of cutaneous MPNSTs. The first case, occurring in a 27-year-old woman with neurofibromatosis I, presented with recent growth of a pre-existing nodule on her back. A biopsy showed a densely cellular area within a conventional neurofibroma composed of atypical, hyperchromatic epithelioid and spindled cells with frequent mitotic figures (MFs). The second case presented in an 88-year-old man with no stigmata of neurofibromatosis as a rapidly growing subcutaneous tumor of the right calf. A biopsy showed a diffuse neurofibroma that abruptly transitioned to a densely cellular proliferation of hyperchromatic atypical spindled cells arranged in short fascicles with frequent MFs. The diagnosis of MPNST was rendered in both cases. MPNSTs of the dermis and subcutis are rare sarcomas. They can occur as sporadic tumors or in the setting of neurofibromatosis. They are often associated with pre-existing neurofibromas. Increase in size of pre-existing neurofibromas is an indication for biopsy. Recognition of the cellular atypia, increased cellularity and mitotic activity is key to the diagnosis.