A Rare Case of Axillary Extramammary Paget's Disease with an Underlying Adenocarcinoma.

Extramammary Paget's disease (EMPD) is an uncommon cutaneous neoplasm almost exclusively located in the vulvar, perianal, and male genitalia regions. Evaluation and management are complicated given the average delay in diagnosis is two years and approximately 30% of cases are associated with underlying malignancies. The axilla is a unique location for EMPD. We report a rare case of a 78-year-old male with axillary EMPD associated with an underlying adenocarcinoma. A 1-cm tender and pruritic erythematous plaque with surrounding erythema appeared in the patient's axilla. An irritated seborrheic keratosis secondarily impetiginized along with irritant contact dermatitis was suspected. Treatment of cefdinir and topical hydrocortisone failed and a biopsy was taken. Microscopic and immunohistochemical examination showed ulceration with an underlying proliferation of atypical glands (Figure 2A) and a nested intraepidermal proliferation with pagetoid spread (Figure 2B). The atypical cells were positive for gross cystic disease fluid protein 15 (Figure 2C), epithelial membrane antigen (Figure 2D), cytokeratin 5/6, and cytokeratin 7. These findings were supportive of an apocrine adenocarcinoma arising in association with EMPD. Wide location excision was performed. Screening for associated malignancies or lymphatic spread is the primary goal during evaluation. Outcomes are favorable when the primary neoplasm is of limited distribution. The accepted treatment for primary lesions is wide local excision, although anatomic tissue constraints necessitate further research into other treatment modalities. To our knowledge, this is the 14th reported case of axillary EMPD with an underlying adenocarcinoma which may help with identification and management of future cases.

A Case of Neonatal Myeloid Sarcoma.

Here we describe a cutaneous neonatal myeloid sarcoma (MS) case with a subsequent diagnosis of acute myeloid leukemia (AML) seven days later. Cytogenetic studies were unusual demonstrating a triple copy of KAT6A abnormality and complex 8;14;22 translocation involving the 8p11.2 region. MS may be the initial finding suggesting associated AML; therefore, the diagnosis of cutaneous MS may allow for expeditious evaluation/treatment of such leukemic disorders.

Cutaneous nocardiosis in an immunocompromised patient.

We describe a case of a 79-year-old man with chronic lymphocytic leukemia (CLL) who presented with ataxia; falls; vision loss; and numerous mobile erythematous nodules on the chin, neck, scalp, and trunk. Computed tomography of the head and chest revealed cavitary lesions in the brain and lungs. Clinically, the skin nodules were believed to represent an infectious process. Two punch biopsies were obtained, which revealed an unremarkable epidermis with a mixed inflammatory infiltrate with abscess formation in the dermis. Gram stain highlighted gram-positive branching bacterial organisms. Similar organisms were identified in a bronchoalveolar lavage specimen. Cultures from skin and blood were positive for Nocardia. Our case serves as a reminder to clinicians and pathologists to keep a broad differential diagnosis when dealing with infectious diseases in immunocompromised patients.

An Incidental Finding of Paratesticular Malignant Mesothelioma During Operation for Hydrocelectomy.

Paratesticular malignant mesothelioma is a rare and potentially aggressive malignancy, accounting for approxi- mately 0.3-1.4 percent of all malignant mesotheliomas. The tumor presents as a painless scrotal mass associated with recurrent hydrocele. We report an incidental case of paratesticular malignant mesothelioma in a 73-year- old man that was found during an operation to remove a progressively enlarging, symptomatic hydrocele. During the procedure the surgeon noted multiple, irregular, extratesticular masses, and subsequently submitted a sam- ple for frozen section analysis. Frozen section assessment revealed a papillary-appearing, malignant tumor and the surgeon proceeded with a radical orchiectomy. Examination of the orchiectomy specimen revealed multiple, yellow-white, papillary, exophytic excrescences that tracked along the hydrocele and coursed up the tunica vagi- nalis of the spermatic cord. Microscopically, the tumor was composed of papillary fronds and nests of malignant cells with enlarged, hyperchromatic, pleomorphic nuclei. Pankeratin and calretinin immunohistochemical stains strongly highlighted the tumor cells, supporting the diagnosis of malignant mesothelioma. Suspicion of malignant mesothelioma as a differential diagnosis in the setting of enlarging hydrocele is imperative, as the care of the patient is dramatically altered to address the aggressive nature of the disease and the unfavorable outcome.

Sebaceous Carcinoma in Situ Masquerading Clinically and Histologically as Paget Disease of the Breast.

Sebaceous carcinoma in situ is a poorly understood and ill-defined entity. In situ sebaceous carcinoma exhibits a similar location pattern to its invasive counterpart in that most commonly has a periorbital distribution. Review of the literature found only seven cases of extraocular sebaceous carcinoma in situ. We present a unique and challenging case of sebaceous carcinoma in situ masquerading both clinically and histologically as Paget's disease of the breast. A 61-year-old female presented to her dermatologist complaining of a 6 mm erythematous waxy papule on her medial right breast. The patient's past medical history was significant for Muir-Torre syndrome. Clinically, the differential diagnosis included Paget disease of the breast, squamous cell carcinoma, and sebaceous carcinoma. A shave biopsy revealed an atypical proliferation of large single cells limited to the epidermis infiltrating in a pagetoid pattern, as well as cohesive nests of round neoplastic cells with mild nuclear atypia, prominent nucleoli, and vacuolated cytoplasm. Histologically, the differential diagnosis included Paget's disease of the breast, squamous cell carcinoma in situ, melanoma in situ, and sebaceous carcinoma in situ. A battery of immunohistochemical stains was performed including CK7, EMA, CAM5.2, CK20, and MART-1. The lesional cells were positive for adipophilin, factor XIIIa, CK7, and EMA and were negative for CAM5.2, CK20, and MART-1 supporting a diagnosis of sebaceous carcinoma in situ. Multiple deeper sections were examined and invasion beyond the epidermis was not identified. This case adds to the paucity of information available regarding extraocular sebaceous carcinoma in situ and warns clinicians of this potential diagnostic pitfall especially in patients with Muir-Torre syndrome.

Scleroderma-like skin changes induced by checkpoint inhibitor therapy.

Checkpoint inhibitors have emerged as beneficial therapies in many different types of malignancy. The most common toxicities of checkpoint inhibitors are immune-related adverse events (irAEs). As clinical experience with these agents increases, more irAEs have been described. We report a case of scleroderma-like skin changes induced by checkpoint inhibitor therapy. A 61-year-old man was treated with nivolumab for oligometastatic renal cell carcinoma. He initially tolerated the therapy well, but after 16 treatments he began experiencing skin thickening and edema of the abdominal wall, which progressed down the trunk and legs. A punch biopsy revealed epidermal attenuation overlying thickened dermal collagen with entrapment and displacement of the eccrine coils and loss of periadnexal adipose tissue. Focally increased plasma cells were present near the junction of the dermis and subcutaneous adipose tissue. Loss of CD34 staining was seen throughout the dermis. These findings were consistent with a diagnosis of scleroderma. After discontinuation of nivolumab and initiation of steroid therapy, the patient's symptoms significantly improved. This case is among the first reports of scleroderma-like changes induced by a checkpoint inhibitor.

Evaluation and comparison of staining patterns of factor XIIIa (AC-1A1), adipophilin and GATA3 in sebaceous neoplasia.

BACKGROUND: Reliable nuclear immunohistochemical stains for sebaceous neoplasms have not been readily available. Positive nuclear staining has been reported for GATA3 and factor XIIIa (AC-1A1). We sought to determine the diagnostic utility of these nuclear stains by comparing their staining pattern to adipophilin, a consistently positive cytoplasmic stain. METHODS: Cases with the diagnosis of sebaceous hyperplasia, sebaceous adenoma, sebaceous epithelioma/sebaceoma, sebaceous carcinoma, and nonsebaceous neoplasms (basal cell carcinoma and squamous cell carcinoma) were examined. Intensity and extent of staining of the basal cells and mature sebocytes were evaluated for each stain. RESULTS: Factor XIIIa (AC-1A1) was 87.3% sensitive and 95.1% specific for all sebaceous neoplasms sand showed high inter-observer reliability. Adipophilin was 83.2% sensitive and 87.8% specific. GATA3 was the least sensitive (80.9%) and specific (75.6%) marker. When factor XIIIa was compared against composite staining of all three markers its staining was still uniquely significant (P = .0210). CONCLUSION: Factor XIIIa (AC-1A1) is a sensitive and specific nuclear marker for sebaceous differentiation. Its diagnostic utility exceeds that of adipophilin. Factor XIIIa should be included in the expanding group of immunohistochemical and special stains which can be utilized to aid in the diagnosis of sebaceous neoplasms.

Alkaptonuria: A Case Report With Diagnostic Challenge.

Alkaptonuria is a rare autosomal recessive metabolic disorder caused by deficiency of homogentisic acid (HGA) oxidase, the only enzyme capable of catabolizing HGA. Deficiency of this enzyme leads to excess HGA which deposits in the connective tissue. We present a case of a 64-year-old woman who was referred to the dermatology clinic for a full body mole check and skin cancer screening. Clinically she had blue/gray pigmentation of the external ear and sclera. Also she had a domed papule on the left cheek with punctate gray pigmentation which was biopsied. Histopathological examination showed a benign dermal nevus and nonpolarizable, yellow-brown, irregular shaped fibers. Subsequent organic acid screen showed markedly elevated urinary HGA, diagnostic of alkaptonuria. On specific inquiry, the patient revealed she had a history of bilateral Achilles tendon rupture, black urine, arthritis, and external ear discoloration for many years. The pigmented material was then considered to be HGA deposition within the dermal collagen fibers. However, without the appropriate clinical data and confirmatory lab findings, the pigmented fragments on skin biopsy represent a diagnostic challenge. Measures like low protein diet and ascorbic acid supplementation will slow down the disease progression and potential complications later in life; however, there is no definitive treatment for the disease. We emphasize the prompt recognition of the clinical signs and symptoms as well as the importance of the microscopic findings.

Combined Melanocytic Nevus, Superficial Congenital and Deep Penetrating Types with Fibroepithelioma of Pinkus, Collision Tumor - A Case Report.

We present a case of collision tumor composed of a combined melanocytic nevus with superficial congenital and deep penetrating components and a fibroepithelioma of Pinkus on the left lumbar back of a 21-year-old male. He presented to the dermatologist for evaluation of numerous moles, and the lesion in question was described as a brown variegated papule with slightly irregular shape and irregular borders. This case is being reported as it is very unusual to see a fibroepithelioma of Pinkus in conjunction with a melanocytic lesion.

Lymphangiectatic Variant of Eccrine Spiradenoma - A Diagnostic Challenge.

Conventional eccrine spiradenoma is a benign, slow growing and painful tumor of the skin. While the tumor does not usually present a diagnostic dilemma, a rare variant with marked stromal lymphedema can be a challenge to interpret. We present a case of lymphangiectatic variant of eccrine spiradenoma in an 82-year-old white male who presented with a persistent left flank lesion for several months. The patient was initially asymptomatic and subsequently developed a suspected abscess that was excised to reveal a 6.5 cm subcutaneous mass. Microscopic examination reveals strands and cords of dark, epithelial, round to oval cells with inconspicuous nucleoli streaming between prominently dilated and congested vascular spaces. Within the cystic component there are small ductular structures. Additionally, prominent stromal lymphedema is present. To the best of our knowledge, there is only one reported case of this entity in the English literature. This case represents a diagnostic challenge and the purpose of reporting it is to alert surgical pathologists, dermatopathologists and dermatologists of the existence of this unusual variant of eccrine spiradenoma.