Metastatic signet ring cell carcinoma of unknown primary origin: a case report and review of the literature

Abstract

In spite of the increasingly sophisticated diagnostic workup, detailed investigations fail to reveal a primary site of origin for about 3-5% of metastatic tumors. The most commonly reported subtype in cancer of unknown primary origin is adenocarcinoma. Signet ring cell carcinoma (SRCC) is a rare poorly differentiated aggressive subtype of adenocarcinoma that most commonly arise from the gastrointestinal tract. It usually presents late and is associated with poor prognosis. Treatment options remain limited to anecdotal reports. However, immunohistochemical studies can be useful in suggesting an origin and therefore may help guide investigations and treatment options. Here we present an unusual case of metastatic SRCC of unknown primary origin presenting as peritoneal carcinomatosis in a 73-year-old man. We also review the literature on metastatic SRCC of unknown primary origin and discuss the relevant findings. This work highlights the importance of collaboration between clinicians and pathologists as well as detailed histopathological, immunohistochemical, and molecular analyses which can help guide investigations and management options.

Signet Ring Cell Carcinoma of Unknown Primary Origin Detected Incidentally by Lymph Node Purification for Thyroid Carcinoma

“…In the present case, careful examinations, including serial EGD, CS, capsule endoscopy, CT scan, and FDG-PET, failed to detect the primary site until death. Al-Taee et al ( 3 ) described a case of SRCC presenting peritoneal carcinoma and reviewed five cases of SRCCs of unknown primary origin. We also searched for similar case reports and found two more cases of SRCC of unknown primary origin published after the review of Al-Taee et al ( 3 , 12 ).…”

“…Al-Taee et al ( 3 ) described a case of SRCC presenting peritoneal carcinoma and reviewed five cases of SRCCs of unknown primary origin. We also searched for similar case reports and found two more cases of SRCC of unknown primary origin published after the review of Al-Taee et al ( 3 , 12 ). SRCC of unknown origin is thus considered to be an extremely rare clinical manifestation.…”

“…As SRCC progresses rapidly, its prognosis seems to be worse than that for tumors without an SRCC component, or for tumors with a known primary origin ( 1 ). In addition, because of the rarity of SRCC of unknown primary origin, data regarding the efficacy of cytotoxic chemotherapeutic agents are limited ( 3 - 7 ). Cytotoxic agents or regimens including cisplatin/irinotecan, 5-fluorouracil, cisplatin/S-1, etc., have been tried, and survival periods of 24-37 months have been reported ( 3 - 7 , 13 ).…”

“…In addition, because of the rarity of SRCC of unknown primary origin, data regarding the efficacy of cytotoxic chemotherapeutic agents are limited ( 3 - 7 ). Cytotoxic agents or regimens including cisplatin/irinotecan, 5-fluorouracil, cisplatin/S-1, etc., have been tried, and survival periods of 24-37 months have been reported ( 3 - 7 , 13 ). In the present case, cisplatin plus S-1, a standard chemotherapy regimen for advanced gastric cancer ( 16 ), was useful for disease control of the bone lesions and for pain relief.…”

“…The most commonly reported subtype of CUP is adenocarcinoma ( 1 , 2 ). Although signet ring cell carcinoma (SRCC) is a poorly differentiated aggressive subtype of adenocarcinoma, SRCC of unknown primary origin has rarely been reported ( 3 - 7 ). We encountered an unusual case of cervical lymph node metastasis of SRCC that was found incidentally during an operation for thyroid cancer.…”