Violaceous nodules of the extensor joints - a clinicopathological challenge.

Antineutrophilic cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a condition characterized by vessel inflammation and may have a variety of etiologies. Among these, cocaine and its common adulterant, levamisole, have been described to contribute to the development of AAV with distinct cutaneous manifestations. Classically, these manifestations involve purpuric or necrotic lesions involving the ears, nose, and extremities. However, we present a case of cocaine-induced AAV presenting with violaceous nodules on the dorsal hands in order to demonstrate that this condition may not always present with retiform purpura and skin necrosis.

Chromoblastomycosis Caused by Fonsecaea monophora Mimicking Lichen Planus.

Chromoblastomycosis is a rare fungal infection acquired by traumatic inoculation of pigmented fungi from an environmental source. The polymorphic presentation of chromoblastomycosis may mimic other dermatologic conditions, leading to delays in diagnosis. Thus, histopathology is critical in identifying the presence of fungi and confirming the diagnosis. We present a case of chromoblastomycosis caused by the organism Fonsecaea monophora mimicking a lesion of lichen planus to highlight the importance of histopathology in the diagnosis of this condition.

Pancreatic Panniculitis: A Case Associated With Acute Pancreatic Allograft Rejection.

We present a unique case of pancreatic panniculitis (PP) in a 42-year-old male with a history of pancreas-after-kidney (PAK) transplant. The patient developed PP due to acute pancreas allograft rejection. Clinical manifestations included fevers, myalgias, arthralgias, and tender erythematous subcutaneous nodules on the lower extremities. A recent hospital admission was noted for acute pancreas allograft rejection related to low tacrolimus levels. Rheumatological and infectious disease workups were negative. Skin nodule punch biopsy confirmed PP with lobular panniculitis, necrotic adipocytes, basophilic debris, and calcification. Pancreatic biopsy showed evidence of parenchymal acute cellular rejection. Lipase and amylase levels were elevated (1781 U/L and 881 U/L, respectively). Treatment involved pulse solumedrol and thymoglobulin for pancreatic rejection, alongside adjustments to immunosuppressive medications. This case highlights the rarity of PP in a PAK recipient and its association with acute pancreas allograft rejection. Importantly, it is the first reported case of PP occurring solely in the context of pancreas transplant rejection, without concurrent kidney damage or rejection. Prompt diagnosis and management led to the resolution of skin and systemic symptoms. In conclusion, this report presents a clinically relevant and unique case of PP resulting from acute pancreas allograft rejection in a PAK transplant recipient. The findings underscore the importance of early diagnosis and management for positive patient outcomes, serving as a reminder to consider underlying pancreatic pathology when encountering PP in transplant recipients.

An Unexpected Postsurgical Phenomenon After Total Knee Arthroplasty: Nummular Eczema: A Case Report and Literature Review.

CASES: Two elderly women each presented with a unilateral, erythematous rash 1 year after total knee arthroplasty (TKA) for osteoarthritis. Both cases were diagnosed as postsurgical nummular eczema (NE) and treated successfully with topical corticosteroids. CONCLUSION: We highlight a novel clinical presentation of postsurgical NE associated with TKA, previously reported only with breast reconstruction. Postsurgical NE may mimic periprosthetic infection or implant-related allergic contact dermatitis. Timely diagnosis and appropriate treatment in these cases prevented unnecessary testing and hospital admission for revision surgery. This case series highlights the varied presentation and wide differential diagnosis associated with postsurgical NE.

Immune Checkpoint Inhibitor-Induced Psoriasiform, Spongiotic, and Lichenoid Dermatitis: A Novel Clinicopathological Pattern.

Immune checkpoint inhibitors (ICIs), a class of anticancer agents that upregulate T-cell response to tumor cells, are associated with immune-related adverse events (irAEs), and the skin is one of the most commonly affected organs. We report the first two cases of a unique ICI-induced clinicopathological entity. A psoriasiform-appearing eruption with psoriasiform, spongiotic, and lichenoid dermatitis pattern on histopathology. A 73-year-old male with stage IV melanoma treated with nivolumab and a 63-year-old female with stage IV colorectal cancer treated with pembrolizumab and TAK-981 separately presented to our clinic with a psoriasiform rash. In both patients, punch biopsy revealed an unusual combination of psoriasiform, spongiotic, and lichenoid dermatitis. Treatment with apremilast in the first patient yielded some improvement, while treatment with ixekizumab in the second patient yielded a complete resolution of the eruption. Our cases add to the growing body of reported immune toxicities related to ICI use and illustrate the utility of targeted immune suppression of pathways in disease phenotype to allow for ICI continuation and optimization of cancer treatment.