A 23‐year‐old man had (a, b) bilateral temporal nodules. The nodules presented with the appearance of temporal ‘horn growth’. The temporal nodules were fixed to the deep plane. (c) Duplex ultrasonography showed temporal arteritis with segmental thickening and microaneurysms. Hypereosinophilia was noted. (d) Histology showed a parietal and perivascular infiltrate. After excision of the temporal artery, the course was favourable without treatment. There was no relapse within 3 years of diagnosis.
diagnosis

A woman in her 60s first presented with superficial spreading melanoma on her right calf, with a Breslow thickness of 3.15 mm and without ulceration.

Over the next 3 years, she had several recurrent right and left inguinal lymph node metastases, all treated surgically. Molecular testing performed on a metastatic lymph node did not reveal BRAF V600 mutation.

At first examination for the present report, a PET-CT scan (positron emission tomography–computed tomography) showed a new metastatic lymph node in the left inguinal area without any other metastases.

Given the patient’s history of lymphedema and multiple surgical procedures, systemic treatment with pembrolizumab, 2 mg/kg every 3 weeks, was begun. A partial response was achieved within 3 months, but after the tenth infusion, the patient developed bilateral secondary Raynaud phenomenon with the typical sequence of white, blue, then red discoloration of the hands and fingers (Figure). This was followed by occurrence of a necrotic lesion on the tip of the right fifth finger. She had no personal or familial history of primary Raynaud phenomenon.
Laboratory tests revealed elevated levels of both anticardiolipin antibodies and lupus anticoagulants. However, β2-glycoprotein 1 antibodies were not elevated. Repeated testing for antiphospholipid antibodies 12 weeks later confirmed positivity.

Results of blood tests including blood cell count, coagulation parameters (fibrinogen, protein C, and protein S levels and antithrombin activity), serum immunoglobulins, serum complements, antinuclear antibodies, and cryoglobulins, were all normal or negative. Doppler ultrasonography of the upper extremities did not show any abnormalities. Skin biopsy was not performed. Based on these observations

Diagnosis??

A 25‐year‐old man with history of asthma, seasonal allergies, and food allergies was referred to our Rheumatologic Dermatology clinic for evaluation of intermittently pruritic plaques on the dorsal hands for more than 10 years.
He endorsed occasional morning stiffness and enlargement over the proximal interphalangeal (PIP) joints and distal interphalangeal (DIP) joints of the hands for the same duration.
The patient denied any history of repetitive trauma to the hands, and there was no family history of psoriasis, rheumatoid arthritis, tuberous sclerosis, or Ehlers‐Danlos disease.
Clinical examination revealed lichenified, mildly erythematous, scaly, ill‐defined plaques of both dorsal hands with soft tissue swelling involving the lateral aspects of the second, third, and fourth PIPs symmetrically (Figure 1). No other abnormal cutaneous lesions were noted on a full body skin exam.
Laboratory studies included a negative rheumatoid factor, and complete blood count, comprehensive metabolic panel, thyroid stimulating hormone, C‐reactive protein, erythrocyte sedimentation rate, anti‐streptolysin O titers, and anti‐DNase B titers were within normal limits. By report, he was HLA‐B27 positive.
Standard radiographs of the bilateral wrists showed non‐specific mild soft tissue swelling most notably around the second through fourth PIP joints, right greater than left; no bony or articular changes were noted.

A punch biopsy of a lesion overlying the medial PIP of the left fourth finger showed acral skin with hyperkeratosis and hypergranulosis (Figure 2). The dermis showed thickened collagen bundles (Figure 2A) and mildly increased CD34‐positive fibroblasts within the dermis. Collagen bundles were separated by widened fenestrations containing abundant mucin (Figure 2B), which was highlighted with colloidal iron staining (Figure 2C). Elastic Van Gieson staining showed sparse, thinned, and elongated elastic fibers (Figure 2D). There was no associated inflammatory infiltrate.

Diagnosis?

A 21‐year‐old Hispanic man with B‐ALL, presented to the hospital after his second cycle of chemotherapy in septic shock due to Escherichia coli bacteremia.
He was treated with broad‐spectrum antibiotics and antifungals due to persistent neutropenic fevers.
On hospital day 16, he developed an eruption of well‐circumscribed, warty‐appearing, nonpruritic, nonpainful, flesh‐colored nodules on his forehead, upper back, and arms (Figure 1), as well as non‐specific left shoulder and bilateral leg pain.
On physical exam, the patient was febrile, tachycardic, and hypotensive, and he appeared chronically ill. His abdomen was distended and tender in the right lower quadrant, with splenomegaly. He had no palpable lymphadenopathy. There was limited range of motion of the affected limbs.

Shave biopsy of two skin lesions from the right elbow revealed a dermal histiocytic infiltrate composed of foam cells and Touton giant cells without mitotic figures, nuclear atypia, or epidermal involvement (Figure 2).
Bone marrow biopsy showed marked nodular histiocytic proliferation involving 40% of the marrow, with positive staining for CD68 and CD163 and negative staining for CD1a, EBER, S100, CD21, CD23, and BRAF V600 mutation, consistent with JXG (Figure 3).
No specific abnormalities were detected by BCR/ABL and chromosome 17 FISH probes. Cytogenetics showed a normal male karyotype. Bacterial, mycobacterial, and fungal cultures were negative. Our laboratory did not perform NRAS, KRAS, MAR2K1 mutational analysis, evaluation for ALK expression, or Factor XIIIa.
A PET scan revealed numerous foci of increased activity throughout the axial and appendicular skeleton and foci of increased tracer uptake in the liver,

Diagnosis????

A 63‐year‐old woman presented with painful desquamative gingivitis (Figure 1A). Clinical examination revealed sloughing of the gingival epithelium upon palpation, consistent with a positive Nikolsky sign. Biopsy revealed a band‐like lymphocytic infiltrate with apoptosis of occasional basal keratinocytes (Figure 1B and C). Direct immunofluorescence examination showed nuclear IgG and IgA (weak) staining within the lower third of the epithelium, as well as shaggy fibrin deposition at a focus of subepithelial split (Figure 1D‐F).

A 65‐year‐old woman complained of difficulty wearing her dentures due to tenderness in the posterior mandible. Physical examination revealed redness and leukoplakia of bilateral posterior mandibular and maxillary ridges. Clinical impression was oral lichen planus (LP). A biopsy was taken from the left buccal mucosa, which showed lichenoid mucositis with mild epithelial hyperplasia and hyperkeratosis (Figure 2A). The inflammatory infiltrate was composed of predominantly lymphocytes and a few plasma cells. Direct immunofluorescence revealed nuclear binding of IgG in the basal and suprabasal epithelial keratinocytes (Figure 2B) and shaggy fibrin deposition along the basement membrane zone

A 61‐year‐old man with a reported history of oral LP was treated with clobetasol gel and prednisone “swish and spit,” which led to improvement but not resolution. Oral examination was remarkable for confluent erythema and erosions of the upper and lower attached gingiva. Skin examination was unremarkable. A punch biopsy was taken from the right gingival buccal sulcus, which showed lichenoid mucositis with basal squamatization and rare cytoid bodies (Figure 3A). Hypergranulosis, hyperkeratosis, and mild squamous atypia were also noted. The lichenoid infiltrate consisted of predominantly lymphocytes and sparse plasma cells. Another biopsy from the anterior buccal mucosa was submitted for direct immunofluorescence study, which revealed nuclear IgG binding of the basal and suprabasal keratinocytes (Figure 3B). Serologic testing for antinuclear antibody (ANA) was negative. Hydroxychloroquine treatment was initiated; however, clinical follow‐up data are not available.

A 70‐year‐old woman with a presumed history of erosive LP had biopsies of her oral mucosa in 2012, which reportedly showed lichenoid inflammation and absence of immunoreactants on direct immunofluorescence. These biopsies were not available for review. Despite management with topical steroids, the patient experienced persistent desquamative gingivitis. A second biopsy from the upper gingiva was taken in 2015 and revealed epithelial hyperplasia with patchy lichenoid lymphocytic inflammation and scarring (Figure 4A). A few cytoid bodies were observed in the areas of lichenoid inflammation. Plasma cells were found in the areas of scarring. Direct immunofluorescence showed strong IgG deposition in the epithelial cell nuclei in at least the basal and suprabasal layers; full‐thickness evaluation was limited by tangential sectioning. Shaggy fibrin deposition was also noted focally at the basement membrane zone.
Diagnosis?