Amelanotic Signet Ring Cell Melanoma Presenting as Breast Lump- A Diagnostic Conundrum

Abstract

Amelanotic signet ring cell melanoma is one of the rare variants of malignant melanoma. Here we are presenting a case of a 58-year-old female with chief complaints of swelling in the left sternal region/breast, and right cervical region. Contrast Enhanced CT scan showed the two well circumscribed lobular mass lesions with central necrosis in the left breast. The radiologist opined the lesions as intramammary nodes. Biopsy from the larger breast mass lesion showed a tumour with cells arranged in discohesive pattern less with hetrogenos morphology. These tumour cells had a predominantly signet ring morphology along with markedly pleomorphic tumour cells and giant cells. These tumour cells were negative for pan CK and positive for S100, HMB45. So the case was diagnosed as metastatic amelanotic malignant melanoma with signet ring morphology.

The Cytodiagnosis of Amelanotic Primary Signet Ring Cell Melanoma at the Unusual Site of the Axilla: A Case Report of a Rare Entity

“…The supportive histomorphological evidence for a primary signet ring cell melanoma involves the presence of non-signet classical malignant melanocytes. The majority of signet ring cell melanomas are amelanotic, which compounds the histomorphological confusion [ 6 , 7 ]. The IHC for S-100, HMB-45, and Melan-A confirms the diagnosis of signet ring cell melanoma.…”

“…One study has described the FNAC of signet ring cells in various types of breast carcinoma in 11 cases, but it did not mention signet ring cell melanoma. The study reported the presence of signet ring cell formations in many cutaneous neoplasms on biopsy material [ 7 ]. it discussed a rare case of amelanotic signet ring cell melanoma presenting as a breast lump [ 7 ].…”

“…The study reported the presence of signet ring cell formations in many cutaneous neoplasms on biopsy material [ 7 ]. it discussed a rare case of amelanotic signet ring cell melanoma presenting as a breast lump [ 7 ]. However, this report does not provide a description of the cytology of the lump.…”

“…There are scarce data in the literature about the cytodiagnosis of signet ring cell melanoma by FNAC. Mostly, the cytodiagnosis of signet ring cell melanoma reported on FNAC involves metastatic lesions in known patients with primary signet ring cell melanomas of other sites [ 6 , 7 ]. A brief report has described the potential diagnostic pitfalls and mimicking of signet ring cell melanoma as signet ring cell lymphoma, liposarcoma, and epithelioid mesenchymal tumors [ 6 , 7 ].…”

Metastatic Malignant Melanoma Mimicking Mammary Mass: A Rare Presentation

“…A definitive diagnosis is reached with pathological examination such as FNAC or biopsy. On histological examination, MM has varied microscopic morphological features that can confuse with other malignant tumors [7]. The presence of melanin pigment within tumor cells is a definitive but very rare feature [2].…”