A Persistent Dark Macule on the Hand of a Hispanic Patient.

A 38-year-old Hispanic man without comorbidities presented to our dermatology clinic for the evaluation of an asymptomatic dark macule on his left hand, which had gradually grown since he was a child. The hyperpigmentation involved the dorsum and palm (Figure 1). The patient was right-handed and denied previous trauma, inflammation, occupational exposure to chemicals, or using any medications. During physical examination, no other similar pigmentation was found on the rest of his body. An incisional biopsy of the left palm was performed (Figure 2). The histopathology revealed the presence of spindle-shaped cells with melanin granules in the superficial and middle dermis, surrounding the blood vessels, and between collagen bundles, which are findings compatible with acquired dermal melanocytosis (1,2). On dermoscopy, we found a pattern of regular pigment with a gray-brown tone and whitish spots within. We discussed the benignity of this rare entity with the patient, and he decided not to pursue treatment. Acquired dermal melanocytosis (ADM) is a rare condition, with isolated presentation on the hand and with less than 10 cases reported (1). Dermal melanocytosis includes several benign pigmented lesions histologically characterized by the presence of melanocytes in the dermis, which are spindle-shaped dendritic cells containing brown melanin pigment. Melanocytes can also be identified with immunoperoxidase staining for S100 and Fontana-Masson melanin stain (2). The physiopathology of ADM remains unclear, but it has been proposed that it involves reactivation of latent dermal melanocytes due to external factors such as trauma, inflammation, chemical exposure, sunlight, drugs, and hormonal treatment with estrogen and/or progesterone (3). ADM with hand involvement usually appears in the Asian population without sex predilection. The lesions develop in adolescence or young adulthood and tend to affect both hands and other body areas such as the face or the legs; there have also been two reported cases in the Hispanic population (both by Fitzpatrick III) (3,4). ADM must be differentiated from ectopic Mongolian spots, plaque-type blue nevi, tinea nigra, or other pigmented neoplasms. A biopsy is mandatory to establish a proper diagnosis. Ectopic Mongolian spots and plaque-type blue nevi are both congenital dermal melanocytoses that may present as bluish macules on the hand. However, these lesions show deep and more widely scattered distribution of melanocytes (1). There have also been some reports of malignant melanoma and acquired dermal melanocytosis that appeared on congenital nevus spilus (5). ADM is a benign condition, and reassurance should be offered to these patients.

Dermoscopic features of actinomycetoma: a case series.

Dermoscopy of mycetoma has white structures as the predominant feature, while white scale and yellowish structures were also consistent in our findings with available literature.

Mycophenolate mofetil and mycophenolic acid for the treatment of eosinophilic fasciitis: report of two cases and literature review.

Eosinophilic fasciitis (EF) is an uncommon autoimmune connective tissue disorder characterized by edema, erythema, and subsequent induration of the extremities. It is commonly treated with corticosteroids but there is no treatment ladder for immunosuppressants or steroid-sparing agents. We report two EF cases treated effectively with mycophenolate mofetil (MMF) or mycophenolic acid (MPA) and present a literature review. We performed a MEDLINE search using the keywords 'eosinophilic fasciitis', 'Shulman syndrome', 'mycophenolic acid', or 'mofetil mycophenolate', and found 8 articles with 27 cases in which MMF or MPA was used. Twenty-nine cases were reviewed (2 reported herein and 27 from the literature search); all patients received a combination of systemic corticosteroids and MMF. MMF/MPA were given as a steroid-sparing agent in 27 (93.1%), in 1 (3.4%) as adjunctive therapy with other immunosuppressants, and in one, as monotherapy 1 (3.4%). Nineteen had a complete response, 6, a partial response, and 2 were unresponsive to diverse immunomodulators; in 2 cases, the outcome was not reported. MMF and MPA show promising therapeutic results and could be a treatment option to reduce corticosteroid related side effects.

Uncoiled linear looped vessels in basal cell carcinoma: a novel morphology.

We describe two cases of nodular basal cell carcinoma presenting with novel morphology of linear looped hairpin vessels under dermoscopy.

Indurated Plaques on the Legs: Think Lymphoma.

Dear Editor, Primary cutaneous diffuse large B-cell lymphoma, leg-type (PCDLBCL-LT) is a rare and aggressive neoplasm. A timely diagnosis may prevent fatal outcomes; physicians should take this entity into consideration when assessing non-specific lesions on the lower limbs. We present a 69-year-old woman with a 1-month history of a firm plaque on her left leg. Physical examination revealed an asymptomatic, indurated, smooth, and erythematous plaque on the pretibial region of her left extremity (Figure 1, a). The rest of the physical examination was normal. Histological examination revealed cohesive sheets of a dense cell infiltrate in the dermis, composed of large round immunoblast-type cells with prominent nucleoli, and the presence of mitoses. Immunohistochemical stains were positive for CD20, Bcl2, and MUM1 (Figure 1, b-d). Additionally, c-MYC and Ki67 exhibited a 20% positivity; CD3 and CD10 were negative. The diagnosis of PCDLBCL-LT was established. Imaging and blood workup ruled out systemic involvement. Treatment with R-CHOP chemotherapy was initiated, with complete tumor regression by the third cycle. The patient completed 6 cycles and has remained disease-free after 18 months. Primary cutaneous B-cell lymphomas (CBCL) are lymphoproliferative disorders that appear on the skin without evidence of extracutaneous manifestations at the time of diagnosis (1). They represent 25 to 35% of all primary cutaneous lymphomas (2). In 2018, an updated version of the 2008 WHO-EORTC classification divided CBCLs into 5 subtypes: PCDLBCL-LT, primary cutaneous marginal zone B-cell lymphoma (PCMZL), primary cutaneous follicle center lymphoma (PCFCL), Epstein-Barr virus-positive mucocutaneous ulcer (EBVMCU), and intravascular large B-cell lymphoma (3). PCDLBCL-LT is the least common subtype, representing approximately 10% of all CBCLs and only 4% of all cutaneous lymphomas (2,3). Although the pathogenesis for most CBCLs is still unknown, positive serology for Lyme disease in a significant number of patients has been recognized as a probable etiologic association (4). PCDLBCL-LT is more frequent in women, and the mean age of presentation is 76 years. It usually presents as erythematous or bluish nodules, and up to 75% of the cases appears on one or both legs (1). Although infrequent, other locations have been reported, including the head, neck, trunk, and upper extremities (5). Workup should include a complete physical exam, skin biopsy, blood tests, and imaging (2,3). Histopathology shows a diffuse infiltrate in the dermis composed of large B-cells (centroblasts and/or immunoblasts) with extension to subcutaneous cellular tissue. These cells have round nuclei that are more than twice the size of normal lymphocytes, with prominent nucleoli. The immunophenotype of PCDLBCL-LT is CD20+, CD79a+, CD10-, and Bcl-6+/-, and strongly expresses Bcl-2, MUM1/IRF4, and FOX-P1 (1-3). Unlike the other indolent subtypes, PCDLBCL-LT is generally more aggressive with a poor prognosis. The 5-year disease survival rate is of approximately 50% (5). Management depends on the body surface area, location, and the patient's age and general health. To date, chemotherapy with R-CHOP remains the first line of therapy for PCDLBCL-LT, resulting in complete remission in up to 92% of cases (2). The prognostic characteristics of most PCDLBCL-LTs require timely and appropriate diagnosis and treatment.

Case Report: Coral Reef Pathogen Aspergillus sydowii Causing Black Grain Mycetoma.

Mycetoma is an infrequent subcutaneous infection caused by true fungi (eumycetoma) or aerobic actinomycetes (actinomycetoma). We report the case of a 62-year-old man with eumycetoma involving the left foot and ankle. Skin biopsy revealed black-brown grains, and in culture, a white colony fungus grew at day 8. Molecular sequencing using ITS1-ITS4 primers identified the species as Aspergillus sydowii. The patient was treated with itraconazole 200 mg twice daily and terbinafine 250 mg daily for 8 months, with complete response and no recurrence after 2.5 years of follow-up. Aspergillus sydowii is a saprotrophic fungus that rarely causes skin or nail disease. No cases of eumycetoma caused by this agent have been previously reported. As its geographic distribution continues to expand, it may increasingly be recognized as a cause of human disease.

Climate, soil type, and geographic distribution of actinomycetoma cases in Northeast Mexico: A cross-sectional study.

BACKGROUND: Mycetoma is a chronic, granulomatous infection of subcutaneous tissue, that may involve deep structures and bone. It can be caused by bacteria (actinomycetoma) or fungi (eumycetoma). There is an epidemiological association between mycetoma and the environment, including rainfall, temperature and humidity but there are still many knowledge gaps in the identification of the natural habitat of actinomycetes, their primary reservoir, and their precise geographical distribution. Knowing the potential distribution of this infection and its ecological niche in endemic areas is relevant to determine disease management strategies and etiological agent habitat or reservoirs. METHODOLOGY/PRINCIPAL FINDINGS: This was an ambispective descriptive study of 31 patients with actinomycetoma. We determined the biophysical characteristics including temperature, precipitation, soil type, vegetation, etiological agents, and mapped actinomycetoma cases in Northeast Mexico. We identified two disease cluster areas. One in Nuevo Leon, with a predominantly kastanozems soil type, with a mean annual temperature of 22°, and a mean annual precipitation of 585.2 mm. Herein, mycetoma cases were produced by Actinomadura pelletieri, Actinomadura madurae, Nocardia brasiliensis, and Nocardia spp. The second cluster was in San Luis Potosí, where lithosols soil type predominates, with a mean annual temperature of 23.5° and a mean annual precipitation of 635.4 mm. In this area, all the cases were caused by N. brasiliensis. A. madurae cases were identified in rendzinas, kastanozems, vertisols, and lithosols soils, and A. pelletieri cases in xerosols, kastanozems, and rendzinas soils. Previous thorn trauma with Acacia or Prosopis plants was referred by 35.4% of subjects. In these states, the presence of thorny plants, such as Acacia spp., Prosopis spp., Senegalia greggi, Vachellia farnesiana and Vachellia rigidula, are common. CONCLUSIONS/SIGNIFICANCE: Mapping this neglected tropical infection aids in the detection of disease cluster areas, the development of public health strategies for early diagnosis and disease prediction models; this paves the way for more ecological niche etiological agent research.

A case of hyperkeratotic crusted scabies.

Patients who are immunocompromised or have cognitive or physical disabilities are at a higher risk of being affected with infections such as crusted scabies. This is a rare skin hyperinfestation by Sarcoptes scabiei var. hominis. The main characteristic of this dermatosis is a thick crust due to the high concentration of mites; in addition, other manifestations such as papules, excoriations, and burrows may be absent. In severe cases, thick yellow-brown crusts and plaques with deep fissures are present. Diagnosis can be made by observing mites, ova, or feces from skin scrapings. Multiple therapies can be used in patients with this condition. Management with patient isolation is important to prevent institutional outbreaks. This disease can have high mortality, primarily due to sepsis. Awareness of this condition and its serious consequences is important to reduce its mortality and morbidity.