Apocrine cystadenoma: A long-standing apocrine hidrocystoma with an adenomatous proliferation.

BACKGROUND: Apocrine cystadenoma is a rare, benign adenomatous cystic neoplasm, the pathogenesis of which is not fully understood. We sought to characterize the clinical, dermatoscopic, and histopathologic features of apocrine cystadenoma and its relationship to hidrocystoma. METHODS: We retrospectively analyzed cases of apocrine cystadenoma and hidrocystoma retrieved from the dermatopathology laboratory information system. RESULTS: Of the 350 cases apocrine cystic lesions, 13 cases of apocrine cystadenomas met the inclusion criteria. The age ranged from 20 to 84 years with an average of 64 years. They were long-standing (duration 3-15 years), slow-growing, large tumors usually found on the scalp. Dermatoscopy accentuated translucent light to dark blue color and prominent vessels that were present more at the periphery. All lesions were multilocular with columnar to cuboidal lining and decapitation secretion. A large portion of the lesion consisted of a simple nonproliferative epithelial lining, identical to that observed in apocrine hidrocystomas, while the proliferative adenomatous component made up a smaller portion with two patterns: (1) tubular proliferation, which either protruded into the cystic cavity or expanded outward peripherally, or (2) papillary projections, which were multiple layers thick with fibrovascular core, sometimes accompanied by tubular proliferation. Immunohistochemical stains showed strong staining for p40 and a sparse number of cells stained for Ki-67 and p53. CONCLUSIONS: The long duration of the lesion and the large areas of simple apocrine epithelial lining suggest that apocrine cystadenomas arise from long-standing apocrine hidrocystomas. However, the retrospective nature of the study from a single institution is a limitation.

Advances in melanoma: epidemiology, diagnosis, and prognosis.

Unraveling the multidimensional complexities of melanoma has required concerted efforts by dedicated community of researchers and clinicians battling against this deadly form of skin cancer. Remarkable advances have been made in the realm of epidemiology, classification, diagnosis, and therapy of melanoma. The treatment of advanced melanomas has entered the golden era as targeted personalized therapies have emerged that have significantly altered the mortality rate. A paradigm shift in the approach to melanoma classification, diagnosis, prognosis, and staging is underway, fueled by discoveries of genetic alterations in melanocytic neoplasms. A morphologic clinicopathologic classification of melanoma is expected to be replaced by a more precise molecular based one. As validated, convenient, and cost-effective molecular-based tests emerge, molecular diagnostics will play a greater role in the clinical and histologic diagnosis of melanoma. Artificial intelligence augmented clinical and histologic diagnosis of melanoma is expected to make the process more streamlined and efficient. A more accurate model of prognosis and staging of melanoma is emerging based on molecular understanding melanoma. This contribution summarizes the recent advances in melanoma epidemiology, classification, diagnosis, and prognosis.

Paraneoplastic Pemphigus/Paraneoplastic Autoimmune Multiorgan Syndrome: Part II. Diagnosis and Management.

In the second part of this Continuing Medical Education article on paraneoplastic pemphigus/paraneoplastic autoimmune multiorgan syndrome (PNP/PAMS), its diagnostic criteria, investigative work-up, and management are reviewed. PNP/PAMS is a rare autoimmune blistering disorder associated with high morbidity and mortality. Recognizing PNP/PAMS's key features and its diagnostic criteria is critical in initiating appropriate work-up. Evaluating PNP/PAMS requires knowledge of its findings on histopathology, direct immunofluorescence, indirect immunofluorescence, and enzyme-linked immunosorbent assay. Lastly, treatments for PNP/PAMS are reviewed with suggestions based on case reports and expert opinions in the literature. LEARNING OBJECTIVES: After completing this learning objective, the reader will be able to identify the criteria necessary for diagnosing paraneoplastic pemphigus (PNP/PAMS), learn how to work-up a diagnosis of PNP/PAMS, and understand important principles in the management of PNP/PAMS.

Paraneoplastic pemphigus/paraneoplastic autoimmune multiorgan syndrome: Part I. clinical overview and pathophysiology.

Paraneoplastic pemphigus/paraneoplastic autoimmune multiorgan syndrome (PNP/PAMS) is a highly fatal autoimmune blistering disease. The condition occurs in patients with underlying benign or malignant neoplasms, most commonly lymphoproliferative disorders. Both humoral and cell-mediated immunities contribute to the pathogenesis, and autoantibodies against plakin family proteins are characteristic. Patients typically present with severe stomatitis and polymorphous skin lesions, which are often resistant to treatment. Bronchiolitis obliterans (BO) is a frequent complication which contributes to the high mortality rate of PNP/PAMS. Given the rarity of this disorder and heterogeneity of clinical presentation, clinicians should maintain a high index of suspicion for PNP/PAMS to avoid delayed diagnosis. In this first part of a two-part continuing medical education (CME) series, risk factors, pathogenesis, and clinical features of PNP/PAMS are discussed.

Errors encountered in the diagnostic pathway: A prospective single-institution study.

BACKGROUND: Biopsy specimens go through a diagnostic pathway before a pathology report is rendered for the clinician. Errors can occur at any step in this pathway. METHODS: A 1-year prospective study was conducted at a single academic institution to identify and characterize errors that occurred in the diagnostic pathway from the clinic to the dermatopathology lab. RESULTS: A total of 25 662 specimens were processed and 190 errors were recorded (an error rate of 0.7%). The most common errors were an incorrect biopsy site (n = 65), incorrect data entry of a correct diagnosis (n = 25), and specimen mix-up (n = 23). There were 17 diagnostic errors. Errors most often occurred in the pre-analytical phase (n = 128). The clinician was responsible for 34.2% of errors, the dermatopathologist for 23.7%, and the histotechnician for 18.9%. Slips were the most common type of human error (n = 156). CONCLUSION: The most common error involved an incorrect biopsy site at the clinical stage. Over two-thirds of errors occurred before the slide reached the dermatopathologist. Diagnostic errors (analytical phase) rarely occurred, and when they did occur, the clinician was most likely to discover the error. Examining and addressing common laboratory errors help to reduce their incidence and lead to quality improvement in dermatopathology.

Exogenous Ochronosis With Ocular Involvement From Chronic Use of Teavigo.

Exogenous ochronosis refers to accumulation of homogentisic acid metabolites in tissues, manifesting as pigmentation of affected tissues. Phenolic compounds are most commonly implicated, including hydroquinone, quinine, phenol, resorcinol, mercury, and picric acid. The affected connective tissues exhibit brownish discoloration when heavily pigmented and the histopathological appearance is characteristic with "banana-shaped" ochre-colored pigment deposits. Herein, the authors describe a rare case of exogenous ochronosis involving the conjunctiva, sclera and skin, as a result of chronic use of Teavigo (94% epigallocatechin gallate), a polyphenol compound with postulated antioxidant and antiapoptotic activity.

Lichen Sclerosus of the Lip.

In this case report, we outline a case of a 36-year-old woman who presented to the dermatology clinic with a history of a hypopigmented macule on her lip. After conducting hepatitis C antibody testing and a shave biopsy, the patient was diagnosed with lichen sclerosus. Because of the increased risk for squamous cell carcinoma, she underwent an anogenital exam, where no lesions were found.

Granulomatous secondary syphilis: Another diagnostic pitfall for the dermatopathologist.

Syphilis is growing ever more prevalent in the United States with its incidence rising every year. Dermatopathologists need to maintain a high index of suspicion to avoid delayed diagnosis of this treatable disease. Accordingly, it is imperative to be aware of its myriad of presentations-including secondary syphilis with granulomatous inflammation. Most cases show aggregations of epithelioid histiocytes associated with plasma cells. Other patterns include an interstitial granuloma-annulare-like pattern, sarcoidal, and tuberculoid pattern. Immunohistochemical stains for Treponema pallidum may be negative, especially in late secondary or tertiary syphilis. We present a case of nodular secondary syphilis with granulomatous inflammation with negative T. pallidum staining.

Musculoskeletal manifestations of syphilis in adults: secondary syphilis presenting with ankle inflammatory arthritis and bone involvement with calvarial and sternal lesions. What the rheumatologist needs to know.

Although the incidence of syphilis reached a historic low in 2000, the number of incident cases has since increased in men and women across the USA. In 2019, men who have sex with men (MSM) accounted for 57% of all primary and secondary (P&S) syphilis cases, and about half of MSM with P&S syphilis are living with human immunodeficiency virus (HIV) infection. Days after infection, Treponema pallidum disseminates and invades tissues distant from the site of inoculation. Once the spirochete disseminates, the host develops an inflammatory response; diagnosis requires a high level of suspicion since syphilis may affect the skin, musculoskeletal, cardiovascular, and central nervous systems. We report a 61-year-old man with virally suppressed HIV infection who presented with polyarthralgia, chest pain, and weight loss, diagnosed with secondary syphilis, manifesting with ankle inflammatory arthritis and bone involvement, of the calvarium and manubrium. Early and late syphilis in adults can manifest with articular and periarticular pathologies, including inflammatory arthritis, tenosynovitis, periostitis, and myositis. Higher clinical suspicion is needed for prompt diagnosis of syphilis in patients who are at risk and suspected of having an autoimmune disease. This report includes a review of the musculoskeletal manifestations of syphilis.

An unusual presentation of pigmented purpuric lichenoid dermatitis.

Pigmented purpuric lichenoid dermatitis (PPLD) is a rare subtype of pigmented purpuric dermatosis, which classically presents with a mixture of lichenoid papules and patches on the bilateral lower extremities. Herein, we describe an unusual case of a 47-year-old man with PPLD who presented with 1-3mm discrete papules without the presence of larger patches. The diagnosis of PPLD should be considered for patients presenting with bilateral symmetric discrete papules on the legs.

Linear Immunoglobulin A (IgA) Bullous Dermatosis Mimicking Stevens-Johnson Syndrome.

Linear IgA bullous dermatosis (LABD) is a rare autoimmune blistering disease characterized by linear IgA deposition along the dermo-epidermal junction on direct immunofluorescence (DIF). LABD appears clinically as erythematous polycyclic lesions in younger patients but can show considerable phenotypic heterogeneity in older patients, often leading to misdiagnoses such as bullous pemphigoid, pemphigus vulgaris, Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN), or other bullous conditions. Cases of LABD mimicking SJS/TEN require prompt skin biopsies for histopathology and DIF for disease differentiation and medical decision-making. In cases of suspected drug-induced LABD or SJS/TEN, identification and removal of the offending agent are paramount. The preferred treatment for LABD is oral dapsone, while SJS/TEN may respond better to cyclosporine or a combination of intravenous immunoglobulin and systemic corticosteroids. This case highlights the rare occurrence of LABD mimicking SJS/TEN and emphasizes the details that clinicians must know to guide patient management.

Diagnosis and treatment of low-risk superficial basal cell carcinoma in a single visit.

INTRODUCTION: Surgical excision remains the most commonly utilized treatment for superficial basal cell carcinoma (sBCC). In the era of cost containment of healthcare, the rising incidence of BCC and the high cost of excision require a continuous search for efficient and cost-effective management. OBJECTIVE: Examine the feasibility of the diagnosis and treatment of low-risk sBCC in a single visit. MATERIALS AND METHODS: Retrospective chart review of sBCCs diagnosed and treated in a single visit. RESULTS: The study identified 151 histologically confirmed sBCCs in 86 patients over a 5-year period, 93 (61.6%) cases of which were diagnosed as low-risk sBCC and treated in a single appointment. The majority of the cases (n = 86) were treated with curettage alone and the rest (n = 7) with a shave removal technique. The average size of the lesion was 0.82 cm located primarily on the trunk and extremities (95.7%). One recurrence on the trunk was observed in the single appointment group. Overall, diagnostic sensitivity was 95.4% and specificity was 92.0%. CONCLUSIONS: Diagnosis and treatment of sBCC in a single visit is an efficient and cost-effective management option for those who are proficient in identifying low-risk sBCC.

Sarcomatoid Dedifferentiated Melanoma: The Diagnostic Role of Next-Generation Sequencing.

ABSTRACT: Sarcomatoid dedifferentiated melanoma (SDDM) represents a diagnostic challenge as this cutaneous spindle cell melanoma lacks expression of classic melanocytic markers including S100, SOX10, Melan-A, HMB45, and MITF. The expression of the emerging melanoma marker preferentially expressed antigen in melanoma (PRAME) in SDDM is largely unknown. In this article, a case of SDDM arising in association with a nodular melanoma is highlighted. A 65-year-old man presented with a several week history of an ulcerated lesion on the right medial knee. A shave biopsy of the lesion revealed a biphasic neoplasm, which consisted of a centrally located poorly differentiated spindle cell component and an adjacent nodular component consisting of atypical melanocytes arranged in nests and fascicles. While the nodular component stained for S100, SOX10, and Melan-A, the spindle cell component failed to stain for these conventional melanocytic markers, only staining diffusely for CD10 and faintly for CD68. Both components stained for PRAME diffusely albeit less intensely within the spindle cell component. Next-generation DNA sequencing assay of the microdissected biphasic components revealed a shared mutation of NRAS. The results of the PRAME immunohistochemical stain and next-generation DNA sequencing assay facilitated in establishing the diagnosis of SDDM in association with nodular melanoma.

An unexpected case of non-uremic calciphylaxis in a patient with multiple risk factors.

A 58-year-old woman with a history of morbid obesity, asthma, and prior warfarin use presented to the hospital with shortness of breath and a three-month history of painful, ulcerated ulcers with retiform purpura of her bilateral distal extremities. A punch biopsy specimen demonstrated focal necrosis and hyalinization of the adipose tissue with subtle arteriolar calcium deposition, findings consistent with calciphylaxis. We discuss the presentation of non-uremic calciphylaxis and review the risk factors, pathophysiology, and interdisciplinary management approach of this rare disease.