Unknown primary Merkel cell carcinoma with cutaneous spread

• Published in: BMJ case reports Vol. 12; no. 2; p. e224834
• Main Authors: Barreira, João Vasco, Valejo Coelho, Margarida Moura, Ribeiro, Catarina, Semedo, Mónica
• Format: Journal Article
• Language: English
• Published: England BMJ Publishing Group LTD 01.02.2019; BMJ Publishing Group
• Series: Case Report
• Subjects: Aged; Antineoplastic Combined Chemotherapy Protocols; Biopsy; Carcinoma, Merkel Cell - diagnostic imaging; Carcinoma, Merkel Cell - pathology; Carcinoma, Merkel Cell - physiopathology; Case reports; Chemotherapy; Combined Modality Therapy; Disease Progression; Family medical history; Fatal Outcome; Female; Humans; Immunotherapy; Knee - pathology; Lymphatic system; Lymphedema; Medical imaging; Medical prognosis; Metastasis; Neoplasms, Unknown Primary - diagnostic imaging; Neoplasms, Unknown Primary - pathology; Neoplasms, Unknown Primary - physiopathology; Palliative Care; Patients; Positron-Emission Tomography; Radiation therapy; Radiotherapy, Adjuvant; Rare Disease; Skin cancer; Skin Neoplasms - diagnostic imaging; Skin Neoplasms - physiopathology; Skin Neoplasms - secondary; Ultrasonic imaging; skin cancer; oncology; dermatology
• ISSN: 1757-790X; 1757-790X
• DOI: 10.1136/bcr-2018-224834

The authors present the case of a woman in the seventh decade of life with medical history of: left nephrectomy for renal tuberculosis and non-Hodgkin’s lymphoma treated with chemotherapy (QT) and radiotherapy. She presented with a 2-month history of non-tender, left inguinal lymph node enlargement. Positron Emission Tomography (PET)—CT —scanshowed hypermetabolic inguinal and retroperitoneal lymphadenopathies, no primary tumour. On the second dermatological examination a pink, 2 cm plaque on the anterior left knee was noted. The histopathological analysis revealed Merkel cell carcinoma. The patient underwent two lines of systemic QT, with life-threatening toxicities limiting treatment. Followed overwhelming disease progression with lymphoedema and numerous skin metastases in the left lower limb. The patient received palliative care until death. The rare incidence of such neoplasia and its uncommon clinical presentation justifies reporting this case and highlights the importance of multidisciplinary teams in the management of cancer patients.