Occult Cause of Paraneoplastic Acanthosis Nigricans in a Patient with Known Breast Dcis: Case and Review

Abstract

bilaterally [ Figure 1(A-B)], the perineum (Figure 2), and neck, although no lymphadenopathy was evident. The features of this exanthem were consistent with a diagnosis of acanthosis nigricans.Given the patient's absence of metabolic risk factors and the rapidity of onset of the cutaneous findings, paraneoplastic acanthosis nigricans (pan) was considered. To our knowledge, pan is most often associated with gastrointestinal tract malignancies and has not been reported in the setting of a ductal carcinoma in situ. Investigations were therefore undertaken to rule out a second occult malignancy that might be a better explanation for the findings.Chest computed tomography (ct) imaging, esophagogastroduodenoscopy, and colonoscopy were all normal, but carbohydrate antigen 19-9 (a tumour marker for pancreatic adenocarcinoma and colorectal cancer) was elevated at 209 kU/L. Abdominal ct revealed a large dilated cystic structure in the gallbladder fossa in which lobulated soft tissue was noted; large masses in the pancreatic bed and porta hepatis were also observed. Marked retroperitoneal adenopathy consistent with metastatic cancer was also noted in the para-aortic region bilaterally.A ct-g uided biopsy of the retroperitoneal lymph nodes demonstrated carcinoma of an undetermined primary. On staining, tumour cells were positive for epithelial membrane antigen and carcinoembryonic antigen, but negative for cytokeratins 7 and 20, estrogen receptor, thyroid transcription factor 1, and calretinin. This staining pattern pointed toward tumours of biliary, pancreatic, and gastric origin, and was not consistent with metastatic breast cancer.The local Tumour Board reviewed the patient's case and concluded that the intra-abdominal findings were most consistent with metastatic cholangiocarcinoma arising from the choledochal cyst. The patient was deemed to have non-curable disease and was offered treatment with palliative chemotherapy. ABSTRACTParaneoplastic acanthosis nigricans (pan) is an infrequently encountered cutaneous manifestation of internal malignancy. Here, we describe a case of pan in the setting of a known breast ductal carcinoma in situ, which, to our knowledge, had not been described in association with pan. As a result, thorough investigation was undertaken to search for another concurrent neoplasm that would better explain the development of pan. In so doing, we identified a coexisting metastatic cholangiocarcinoma. We thus conclude that when pan is observed in an uncommon association with a known malignancy, further investigation should be undertaken to explore whether a more likely occult culprit exists. KEY WORDSAcanthosis nigricans, paraneoplastic acanthosis nigricans, cholangiocarcinoma, ductal carcinoma in situ CASE DESCRIPTIONA 51-year-old woman was seen in consultation in the dermatology clinic for progressive pruritic skin changes affecting the axilla, groin, and neck. She had been referred by her oncologist, who was managing her recently diagnosed breast cancer. Definitive treatment had been initiated and co...

Malignant Acanthosis Nigricans, Florid Cutaneous Papillomatosis and Tripe Palms Syndrome Associated with Gastric Adenocarcinoma - a Case Report

“…Malignant acanthosis nigricans (MAN) is a rare obligate paraneoplastic dermatosis (22) which accounts for 20% of all acanthosis nigricans cases (18,23). Th e term MAN is recognized and accepted, but as such it is not malignant, it only cooccurs with cancer (1,24).…”

Acanthosis Nigricans in a Patient with Urothelial Carcinoma Treated with PD-L1 Inhibitor Avelumab, and Secondary Adrenal Insufficiency

“…Some patients may require retinoids or photochemotherapy (PUVA) with persistent AN; however, majority only require symptomatic treatment. In addition, the occurrence of AN usually precedes the diagnosis of the underlying cause [ 1 , 8 , 9 ]. However, this case report details that the presence of AN can be in the setting of both benign and paraneoplastic causes.…”

Malignant acanthosis nigricans as the marker of a developing tumor

“…Изменение цвета кожных покровов связывают с развитием гиперкератоза. Это дает основания считать термин «черный акантоз» описательным, так как пролиферации меланоцитов не происходит [8][9][10][11][12][13][14].…”