Adenoid cystic carcinoma (ACC) is a rare carcinoma that typically arises in salivary glands but can also occur in other sites including skin. Primary salivary ACC is a locally aggressive tumor characterized by local recurrence and late metastasis. Primary cutaneous ACC is found predominately on the scalp and is more indolent than salivary ACC; and, despite a high incidence of local recurrence, metastases are exceedingly rare.A 62-year-old white male presented with a 6-mm mobile, blue-tinted nodule on the left mid scalp unchanged for several years.The histopathological findings of an excisional biopsy were diagnostic for a primary cutaneous ACC. Immunohistochemistry demonstrated focal positivity for p16.Primary cutaneous ACC is a rare malignancy that should be considered in the differential diagnosis of adnexal neoplasms and, when occurring on the head and neck, must be distinguished from cutaneous involvement by salivary ACC. The majority of reported salivary ACC with p16 protein expression were not positive for high-risk human papilloma virus by in situ hybridization. Immunostaining for p16 has previously been reported in salivary gland ACC. This is the first report in the English literature of p16 immunoexpression in primary cutaneous ACC.
The morphology of urothelial carcinomas, particularly when poorly differentiated or in metastatic sites, is not distinctive and overlaps significantly with other poorly differentiated nonurothelial carcinomas. Currently, there is no widely used single marker or panel of markers to confirm urothelial origin. We evaluated a panel consisting of antibodies to uroplakin III (UROIII), thrombomodulin (THR), high molecular weight cytokeratin (HMWCK), and cytokeratin 20 (CK20) in a wide range of urothelial tumors. Immunohistochemistry was performed on 112 paraffin-embedded urothelial neoplasms: 14 low malignant potential, 16 low-grade noninvasive, 16 high-grade noninvasive, 36 invasive, and 25 metastatic and 5 small cell carcinomas of the urinary bladder. Tissue microarray analysis was used to examine 498 tissue cores of nonurothelial tumors and normal tissue using antibodies to UROIII, THR, and HMWCK. Overall positive staining results in all urothelial tumors are as follows: UROIII, 64 of 112 (57.1%); THR, 77 of 112 (68.8%); HMWCK, 88 of 110 (80%); and CK20, 53 of 110 (48.2%). The expression of the four markers varied with tumor grade and stage. All small cell carcinomas were negative for all markers. Variant morphologic subtypes showed similar staining as conventional urothelial carcinomas. Tissue microarray analysis showed no UROIII immunoreactivity in tissue cores of nonurothelial tumors. THR was expressed by a limited number of nonurothelial cores (10 of 37 [27%] non-small cell lung carcinomas, 2 of 36 [5.6%] lymphomas). HMWCK was expressed by 43.8% of non-small cell lung carcinomas and essentially absent in other nonurothelial tumor cores. Based on the results of the study, the expression of UROIII in a tumor is essentially diagnostic of urothelial origin; however, it is expressed in only slightly more than half of urothelial tumors. The coexpression of THR, HMWCK, and CK20 strongly suggests urothelial origin. The coexpression of two of three non-UROIII markers (THR, HMWCK, CK20) suggests urothelial origin but requires clinicopathologic correlation. The results of the study indicate a role for an antibody panel that includes UROIII, THR, HMWCK, and CK20 in the diagnosis of urothelial tumors.
Salivary duct carcinoma (SDC) is a high-grade malignant tumor exhibiting aggressive growth with early regional and distant metastasis. We report a case of SDC in a 53-yr-old male with distant metastasis to an inguinal lymph node. The diagnosis of the primary tumor as well as the metastatic lesion was accomplished by fine-needle aspiration (FNA). Aggressive clinical management appears to be the main therapeutic option for long-term survival. Therefore, establishing an accurate preoperative diagnosis by FNA can have both clinical and prognostic relevance.
Primary cutaneous neoplasms of myoepithelial differentiation are uncommon. Cutaneous myoepithelial carcinomas are rare. We report a case of cutaneous myoepithelial carcinoma in a 47-year-old man with a history of end-stage renal disease and renal transplant 19 years prior who presented to the hospital with a 3-month history of diffuse bone pain and an ulcerated scalp mass with multiple satellite lesions. This case illustrates a rare instance of metastatic disease from primary cutaneous myoepithelial carcinoma.
A 42-year-old HIV-positive man (CD4 count, 29 cells/μl) developed an asymptomatic papulo-squamous eruption 1 week after beginning trimethoprim–sulfamethoxazole (TMP–SMX) (Figure 1). The eruption progressed despite discontinuation of TMP–SMX. Three consecutive syphilis serologies (rapid plasma reagin) with dilutions and serum treponemal IgG antibody were negative. The patient was referred to the dermatology department. A lesional skin biopsy demonstrated a superficial and deep mixed inflammatory infiltrate with numerous plasma cells. No mycobacterial or fungal organisms were identified by histochemical stains. Immunohistochemistry for Treponema pallidum using a red chromagen showed numerous spirochetes in the epidermis and dermis, confirming the clinically suspected diagnosis of secondary syphilis (Figure 2). Empirical therapy for syphilis had not been initiated due to a documented penicillin allergy. After diagnostic confirmation, a 4-week course of oral doxycycline 100 mg twice daily led to complete resolution of the eruption at 6 months (Figure 3). Syphilis seronegativity highlights a diagnostic challenge and has been reported in severely immunocompromised patients such as those with HIV.1Hicks C.B. Benson P.M. Lupton G.P. Tramont E.C. Seronegative syphilis in a patient with the human immunodeficiency virus (HIV) with Kaposi sarcoma.Ann Intern Med. 1987; 107: 492-495Crossref PubMed Scopus (222) Google Scholar, 2Fowler Jr., V.G. Maxwell G.L. Myers S.A. Shea C.R. Livengood 3rd, C.N. Prieto V.G. et al.Failure of benzathine penicillin in a case of seronegative secondary syphilis in a patient with acquired immunodeficiency syndrome: case report and review of the literature.Arch Dermatol. 2001; 137: 1374-1376PubMed Google Scholar A high index of suspicion and decreased reliance on serologies for diagnosis and follow-up must be maintained for immunocompromised patients.1Hicks C.B. Benson P.M. Lupton G.P. Tramont E.C. Seronegative syphilis in a patient with the human immunodeficiency virus (HIV) with Kaposi sarcoma.Ann Intern Med. 1987; 107: 492-495Crossref PubMed Scopus (222) Google Scholar Close clinical follow-up for evidence of treatment failure and/or recurrent disease is critical for seronegative patients diagnosed with syphilis.2Fowler Jr., V.G. Maxwell G.L. Myers S.A. Shea C.R. Livengood 3rd, C.N. Prieto V.G. et al.Failure of benzathine penicillin in a case of seronegative secondary syphilis in a patient with acquired immunodeficiency syndrome: case report and review of the literature.Arch Dermatol. 2001; 137: 1374-1376PubMed Google Scholar, 3Zetola N.M. Klausner J.D. Syphilis and HIV infection: an update.Clin Infect Dis. 2007; 44: 1222-1228Crossref PubMed Scopus (268) Google ScholarFigure 2Lesional skin immunohistochemistry for Treponema pallidum demonstrating spirochetes.View Large Image Figure ViewerDownload Hi-res image Download (PPT)Figure 3Post-therapy: complete clinical resolution of the skin lesions at 6 months after the initial evaluation.View Large Image Figure ViewerDownload Hi-res image Download (PPT) Conflict of interest: None to disclose.
Nivolumab is a human monoclonal antibody used to treat malignancies, including melanoma, non-small cell lung cancer, and advanced renal cell carcinoma (RCC).1 Nivolumab acts via inhibition of T-lymphocytes by targeting the programmed cell death-1 receptor.2 Despite the checkpoint inhibitor's success in treatment response, immunomodulatory therapies are not without risks, as programmed cell death-1 inhibition has led to immune-related cutaneous adverse events, including rash (14.3%), pruritus (13.2%), and, in severe cases (1.4%), Steven Johnson syndrome/toxic epidermal necrolysis.
PEComas represent a family of uncommon mesenchymal tumors composed of “perivascular epithelioid cells” with a distinct immunophenotype that typically shows both myogenic and melanocytic differentiation. The PEComa family includes angiomyolipoma ( AML ), clear cell “sugar” tumor of the lung and extra pulmonary sites, lymphangioleiomyomatosis and clear cell myomelanocytic tumor of the falciform ligament/ligamentum teres. Very rarely, PEComas may arise in the skin. Primary cutaneous PEComas typically display a dermal proliferation of epithelioid cells with pale, clear, or granular pink cytoplasm arranged in nests and trabecula with an intervening arborizing network of delicate capillaries. Primary cutaneous PEComas have a lower frequency of myogenic marker expression than their deep soft tissue and visceral counterparts. They also often express strong diffuse CD10 , leading to potential confusion with metastatic renal cell carcinoma. Most cases behave indolently. We report 5 additional cases of this rare entity. All showed classic histologic features and expression of either HMB ‐45 and/or Melan‐A/ MART ‐1. Four cases were tested for myogenic markers (2 were positive & 2 were negative). Three cases were tested for CD10 (all 3 were positive). All of our cases with clinical follow‐up behaved indolently. Table 1 provides a summary of findings for all 5 cases in our series.
