-transparent.png){kind=logo}
The fine needle aspiration findings in a lymph node involved by signet-ring cell melanoma, a very rare variant of malignant melanoma, are reported. The patient had a history of superficial spreading melanoma of the right foot, treated 10 years earlier by below-the-knee amputation. He presented with a right groin mass. Fine needle aspiration of the mass yielded poorly cohesive, large cells with eccentric nuclei and abundant, eosinophilic cytoplasm; many of them exhibited a signet-ring appearance. Melanin pigments were identified in a small proportion of tumor cells, and a diagnosis of metastatic melanoma was made. The subsequent lymph node excision revealed a metastatic tumor composed of polygonal and signet-ring cells that were positive for S-100 protein and HMB-45 but not cytokeratin. Nearly all reported cases of signet-ring cell melanoma occurred as metastatic or recurrent disease. It is important not to mistake signet-ring cell melanoma for adenocarcinoma in aspiration cytology, and a constellation of clinical features and of histochemical and immunohistochemical findings enables a correct diagnosis to be reached.
W Y Tsang, and
J K Chan, and
L T Chow
January 1999,
Acta cytologica,
W Y Tsang, and
J K Chan, and
L T Chow
October 1987,
Indian journal of pathology & microbiology,
W Y Tsang, and
J K Chan, and
L T Chow
June 2023,
Oncology letters,
W Y Tsang, and
J K Chan, and
L T Chow
January 2020,
Case reports in oncology,
W Y Tsang, and
J K Chan, and
L T Chow
September 2011,
Lung cancer (Amsterdam, Netherlands),
W Y Tsang, and
J K Chan, and
L T Chow
July 2006,
Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics,
W Y Tsang, and
J K Chan, and
L T Chow
January 1991,
Actas urologicas espanolas,
W Y Tsang, and
J K Chan, and
L T Chow
October 2000,
Actas urologicas espanolas,
W Y Tsang, and
J K Chan, and
L T Chow
January 1980,
Pathology,
W Y Tsang, and
J K Chan, and
L T Chow
January 2001,
Hematology (Amsterdam, Netherlands),
