Prostatic signet-ring cell carcinoma: case report and literature review

Prostate Adenocarcinoma with Signet-Ring Cells and Features of Mucin: A Clinical Case and Literature Review

Introduction: Signet-ring cells are typically associated with mucin-secreting epithelium; thus, they are most commonly found in the gastrointestinal tract, but not exclusively. Primary signet-ring cell carcinoma of the prostate is a rare and poorly differentiated, aggressive acinar adenocarcinoma variant with a grim prognosis. Clinical Case: In June of 2023, a 54-year-old Caucasian male presented with a complaint of lower urinary tract obstructive symptoms with occasional macrohematuria, non-specific body aches, and shortness of breath. A prostate specimen obtained in transurethral resection of the prostate was sent for histopathological examination. After a series of extraprostatic diagnostic workups, including fibrogastroduodenoscopy, colonoscopy computed tomography imaging, and immunohistochemical studies, the patient was diagnosed with primary prostatic signet-ring cell adenocarcinoma stage IV. Unfortunately, due to the advanced stage of the disease, PE, and third-degree thrombocytopenia, the patient was not a candidate for chemotherapy and died of cardiopulmonary insufficiency later that week. Discussion: Prostatic signet-ring cell carcinoma accounts for 0.02% of all prostate adenocarcinoma cases. Due to its nature and epidemiology, a diligent extraprostatic investigation has to be carried out. The disease often presents with unremarkable clinical symptoms and variable serum prostate-specific antigen results, which may contribute to its late diagnosis. Inconsistent immunohistochemical findings and an unpredictable response to hormonal treatment together pose both diagnostic and therapeutic challenges that negatively affect the prognosis. Conclusions: This study highlights the importance of a multidisciplinary approach and the need for diagnostic and therapeutic consensus within the research community in search of the primary site of the disease, which may positively influence the prognosis.

A Case of Prostatic Signet-Ring Cell-like Carcinoma with Pagetoid Spread and Intraductal Carcinoma and Long-Term Survival: PD-L1 and Mismatch Repair System Proteins (MMR) Immunohistochemical Evaluation with Systematic Literature Review

Prostatic adenocarcinoma (PA) is the second most common malignancy in men globally. Signet-ring cell-like adenocarcinoma (SRCC) is a very rare PA subtype, with around 200 cases reported in the English literature. Histologically, the tumor cells show a vacuole compressing the nucleus to the periphery. Pagetoid spread in acini and ducts is usually related to metastases from urothelial or colorectal carcinomas, less commonly associated with intraductal carcinoma (IC); histologically, the tumor cells grow between the acinar secretory and basal cell layers. To our knowledge, we report the first prostatic SRCC (Gleason score 10, stage pT3b) associated with IC and pagetoid spread to prostatic acini and seminal vesicles. To our systematic literature review (PRISMA guidelines), it is the first tested case for both PD-L1 (<1% of positive tumor cells, clone 22C3) and mismatch repair system proteins (MMR) (MLH1+/MSH2+/PMS2+/MSH6+). We found no SRCC previously tested for MMR, while only four previous cases showed high expression of another PD-L1 clone (28-8). Finally, we discussed the differential diagnoses of prostatic SRCC.

Diagnosis and Management of Primary Prostatic Signet Ring Cell Carcinoma: Single-Center Experience

The purpose of the study was to retrospectively summarize the diagnosis and management of 10 primary prostatic signet ring cell carcinoma (PPSRCC) cases in our center. Ten PPSRCC patients diagnosed at the First Affiliated Hospital of Nanjing Medical University from November 2014 to December 2020 were included. Clinical characteristics, image features, therapeutic procedures, histological diagnosis, and outcomes were retrospectively analyzed. All patients received prostate-specific antigen (PSA) examination preoperatively. Nine of them accepted multiparametric magnetic resonance imaging (mpMRI) due to elevated PSA value, and further biopsied. Among them, five patients were diagnosed as prostatic adenocarcinoma and the other four cases were found a mixture of signet ring cell carcinoma (SRCC) and adenocarcinoma. Furthermore, gastrointestinal endoscope and abdominal computed tomography (CT) did not find SRCC originating in gastrointestinal tract. Therefore, these cases were considered to be PPSRCC. Nine patients accepted laparoscopic or robot-assisted RP. Only one patient with normal PSA adopted transurethral resection of the prostate. Postoperative pathological results confirmed SRCC mixed with prostatic adenocarcinoma in nine cases, and only one patient with pure SRCC. After surgery, nine patients received adjuvant hormone therapy, one of which accepted radiotherapy simultaneously. The patient with pure SRCC did not accept any adjuvant therapy postoperatively. During a mean follow-up of 31.9 months, only four patients were alive without disease progression. In summary, PPSRCC is a rare malignant tumor with few specific symptoms, rapid disease progression, and poor prognosis and is frequently accompanied by high-grade prostate adenocarcinoma patterns. There is still no clear and effective strategy to improve the prognosis.

Signet-ring cells in pleural and peritoneal effusions identified on Wright stains – A diagnostic pitfall

Objectives:

Signet-ring cells (SRCs) in effusion specimens represent a diagnostic challenge. In this study, a consecutive series of pleural and peritoneal effusions with benign SRCs are examined and compared with malignant SRCs.

Material and Methods:

We reviewed consecutive Wright-stained serous effusion slides and searched for cases with SRCs. Corresponding ThinPrep slides and clinical histories were reviewed. Cytology cases with known signet-ring adenocarcinoma were retrieved and reviewed.

Results:

Four hundred Wright-stained serous effusions were reviewed. Eighteen cases were identified with SRC-like cells. Thirteen patients had liver cirrhosis, three patients had end-stage renal disease, one patient had a history of pancreatic adenocarcinoma, and one patient had endometrioid carcinoma. For the latter two patients, the primary tumor showed no histologic findings of signet-ring features. In all cases, no SRCs were found on the corresponding ThinPrep slides. Five cytology cases with malignant SRCs were reviewed. Benign SRCs have a uniformly pale and markedly distended cytoplasm, and the nuclei are thin and curved. The malignant SRCs showed larger non-curved nuclei and bubbly mucin-containing cytoplasm.

Conclusion:

Mesothelial cells and histiocytes can mimic signet-ring adenocarcinoma cells on Wright-stained slides. Correlation with ThinPrep specimens is necessary before reporting, as the SRCs typically are not present in ThinPrep preparations.

Formation of intracellular lumina in human prostate carcinoma (DU145) cells, maturation into signet cells, and the cribriform morphology of tumors

The intracellular or intracytoplasmic lumen (IL) is an enigmatic histological structure that occurs in various tumor cells. A reassessment of diverse ILs fine-structure micrographs obtained out of previous studies encompassing the human prostate carcinoma (DU145) cell line and xenotransplanted carcinomas enabled us to propose aspects of ILs development in cancer cells: a combination of altered expressions in intercellular contacts and their cytoskeletal components would favor a disarray of self-apical polarity orientation; those defects, associated with a local, entwined enriched membranous structures growing as microvilli-like formations out of a disrupted endoplasm and trans-Golgi sorting, create ILs in cells' perikarya. These misplaced intracytoplasmic domains can become enlarged through spaces made between the finger-like structures by accruing membranes of coalescent intracytoplasmic vesicles then adding microvilli and glycocalyx to constitute ILs. Cationic mucins added with or without a progressive or total loss of microvilli and content generate signet or ring cell, while ILs enlarge. Variable build-ups of these cells' populations in carcinomas result in architectural mix-up of adjacent cells around these voids, misconstrued as new lumen, and establish a "cribriform" tumor pattern that often implies a poor cancer prognosis. Alternatively, cytotoxic changes caused by anticancer pro-oxidant treatment favor membrane alterations and exaggerate the ILs in xenotransplants into intracellular crypts that accompany other tumor degenerative changes.

Primary signet ring cell carcinoma of the prostate

A 61-year-old Korean man was referred to our institution because of high prostate-specific antigen (PSA) (8.1ng/mL) and frequency, nocturia that had lasted for the previous 4 months. The first transrectal ultrasonography (TRUS)-guided prostate biopsy result was benign prostatic hyperplasia. About 3 years later, the patients revisited our institute for elevated PSA (14.7 ng/mL) and back pain. The patient underwent a second TRUS-guided prostate biopsy. Histological examination and immunohistochemical staining showed a signet ring cell carcinoma (SRCC). Also there were multiple bony metastasis. Androgen deprivation therapy (ADT) was started. Nine months later, the patient was diagnosed with hormone refractory prostate cancer and the ADT was changed into docetaxel chemotherapy. The patient died after 2 cycles of chemotherapy. We report this case of a SRCC of the prostate and review the literature.

Expression of CD7, CD20 and CDX-2 in a secondary signet-ring cell tumor of the prostate: a case report

As is well-known, signet ring cell carcinoma (SRCC) rarely appears as a histological finding in the prostatic tissue. Nevertheless, a differentiation should be made between a primary tumor and a metastatic disease. We describe the case of a 52-year-old man with lower urinary tract symptoms, serum total PSA of 0.2 ng/ml, elevated serum CEA and CA19-9 levels. Two years prior to presentation, he underwent total gastrectomy with histological findings indicating poor differentiated adenocarcinoma with signet-ring cell. A palpable nodule was found on digital rectal examination and for this reason he underwent 12-core transperineal prostate biopsy with a diagnosis of poor differentiated adenocarcinoma with signet-ring cell and adipose tissue infiltration. Immunohistochemical examinations revealed positivity for PAS, CK7 and CDX-2, focal positivity for CK20 and negativity for PSA and PSAP. The diagnosis of a prostatic secondary SRCC was possible given the positivity to CK7, CDX-2, focal positivity to CK20 and negativity to PSA.

Mesothelioma with signet-ring cell features: report of 23 cases

Signet-ring cell mesothelioma is uncommon and only two case reports have been published on this mesothelioma variant, both of which were initially misdiagnosed as signet-ring cell carcinoma. Herein are reported 23 signet-ring cell mesotheliomas that were investigated by immunohistochemistry, 12 of which were also studied by electron microscopy. Twenty-one of the cases originated in the pleura and two in the peritoneum. For comparison purposes and in order to determine the value of these techniques in the differential diagnosis of these tumors, seven cases of signet-ring cell lung adenocarcinoma were also studied. All signet-ring cell mesotheliomas were positive for calretinin, keratin 5/6, keratin 7, and mesothelin, 93% for podoplanin, and 91% for WT1; whereas, none reacted for MOC-31, CEA, TAG-72, CD15, TTF-1, napsin A, or CDX2. Among signet-ring cell lung adenocarcinomas, 100% were positive for keratin 7, CEA, and napsin A, 86% each for TTF-1 and TAG-72, 71% for CD15, and 14% for mesothelin, while all were negative for calretinin, keratin 5/6, WT1, podoplanin, and CDX2. After analyzing the results, it is concluded that the panels of markers used in the differential diagnosis of this mesothelioma variant should include those markers that are usually expressed in mesotheliomas (eg, calretinin, keratin 5/6, WT1, and podoplanin), broad-spectrum carcinoma markers that are frequently expressed in adenocarcinomas regardless of their site of origin (eg, MOC-31 and CEA), and organ-associated markers (eg, TTF-1 and napsin A for lung), which allow the site of origin of a metastatic adenocarcinoma to be established. Electron microscopy can be very useful as it permits the identification of characteristic ultrastructural mesothelioma and adenocarcinoma markers, and it also allows a better understanding of the morphologic features seen on routine light microscopy. Pathologists should be aware of this mesothelioma subtype as it can potentially be confused with other tumors that exhibit signet-ring features.

Mucin-producing tumors and tumor-like lesions involving the prostate: a comprehensive review

Mucin-producing tumors of the prostate include both primary and secondary tumors with mucinous differentiation or features involving the prostate gland. These tumors are relatively rare and have variable prognostic and therapeutic implications. Primary mucinous (colloid) adenocarcinoma of the prostate is defined as prostatic adenocarcinoma with mucinous differentiation involving 25% or more of the entire tumor. Another primary tumor of the prostate that may have mucinous features is primary mucin-producing urothelial-type adenocarcinoma of the prostate (mucinous prostatic urethral adenocarcinoma). Primary mucin-producing urothelial-type adenocarcinoma of the prostate is a distinct entity that typically arises from the prostatic urethra possibly from urethritis glandularis or glandular metaplasia with malignant transformation, and it is analogous to adenocarcinoma with mucinous differentiation arising from the urinary bladder. Signet ring cell tumors of the prostate, though rare, may also have mucinous features. Secondary tumors with mucinous differentiation that may involve the prostate include adenocarcinomas of the urinary bladder and colorectum. Pathologists should also be aware of mucin-producing tumor-like lesions involving the prostate, including mucinous metaplasia, and benign Cowper glands that may mimic malignancy. Herein we present an updated and comprehensive review of the clinicopathologic, immunohistochemical, molecular, and prognostic features of mucinous tumors and tumor-like lesions involving the prostate gland, with emphasis on mucinous prostatic adenocarcinoma and its mimickers, including potential diagnostic pitfalls.

Younger age is an independent predictor for poor survival in patients with signet ring prostate carcinoma

Objective. The aim of this study was to examine the epidemiology, natural history, treatment pattern, and predictors of long-term survival of signet ring prostate carcinoma (SRPC) patients based on the analysis of the national Surveillance, Epidemiology, and End Results (SEER) database. Methods & Results. Between 1980 and 2004, a total of 93 patients with pathologically confirmed SRPC were identified. The mean age was 70 ± 11 years old. 82.8% of the patients had poorly or undifferentiated histology grade. 13.9% patients presented with metastatic disease. The 1-, 3-, and 5-year cancer-specific survival rates were 94.6%, 89.6%, and 83.8%, respectively. Using multivariate Cox proportional hazard model, younger age (40-50 versus age >70 yrs, P = .01), advanced tumor stage (distant versus local/regional, P = .02), and earlier diagnosis year (before 1995 versus after 1995, P = .01) were predictors of worse cancer specific survival. Conclusions. Despite more aggressive cancer therapy, younger SRPC patients had a worse cancer specific survival. This information could be useful when counseling these patients and emphasizes the need for new strategies and molecular-based therapeutic approaches for younger patients with SRPC.

Primary signet ring cell carcinoma of the prostate

Nine patients treated with primary signet ring cell carcinoma of the prostate were identified among 29,783 cases of prostate cancer evaluated at Mayo Clinic from January 15, 1970, until January 2, 2009. A PubMed search of the English-language literature published from January 1, 1980, to January 1, 2010, was then performed using the key words signet ring cell and prostate, identifying 42 cases. This study reviews those cases, along with the additional 9 reported herein, and evaluates clinical characteristics, histologic diagnoses, treatment modalities, and outcomes. Mean age at diagnosis was 68 years (range, 50-85 years), and mean prostate-specific antigen level was 95.3 ng/mL (range, 1.9-536.0 ng/mL; to convert to μg/L, multiply by 1). Most patients (66%) had non-stage IV carcinoma, the most common Gleason sum was 8 (33%), and mean survival was 29 months. The presence of a primary signet ring cell carcinoma of the prostate was best confirmed by negative findings on gastrointestinal work-up, a positive stain for prostate-specific acid phosphatase, and negative carcinoembryonic antigen test results.

Immunohistochemical staining of Reg IV and claudin-18 is useful in the diagnosis of gastrointestinal signet ring cell carcinoma

Signet-ring cell carcinoma (SRCC) is a unique subtype of adenocarcinoma that is characterized by abundant intracellular mucin accumulation and a crescent-shaped nucleus displaced toward one end of the cell. Identification of an SRCC's primary site is important for better planning of patient management because the treatment and prognosis differs markedly depending on the origin of the SRCC. In the present study, we analyzed the immunohistochemical characteristics of 94 cases of SRCC, including 21 cases of gastric SRCC, 16 of colorectal SRCC, 10 of breast SRCC, and 47 of pulmonary SRCC, with antibodies against Reg IV and claudin-18, which we previously identified as gastric cancer-related genes. We also tested known markers cytokeratin 7, cytokeratin 20, MUC2, MUC5AC, caudal-related homeobox gene 2 (CDX2), thyroid transcription factor-1, mammaglobin, gross cystic disease fluid protein 15, and estrogen receptor. All 21 cases of gastric SRCC and 16 cases of colorectal SRCC were positive for Reg IV, and the remaining SRCCs were negative. Eighteen of 21 (86%) gastric SRCCs and 6 of 16 (38%) colorectal SRCCs were positive for claudin-18, whereas another SRCCs were negative. In conclusion, Reg IV staining and claudin-18 staining can aid in diagnosis of gastrointestinal SRCC.

A new case of signet ring cell carcinoma of the prostate

Primary signet ring cell carcinoma of the prostate is a very rare variant of prostate cancer. Herein, we report a new case of primary signet ring cell carcinoma of the prostate in an 85-year-old man with voiding disorder and hematuria. Based on this case, we present the anatomopathologic, clinical, and therapeutic aspects of this rare entity.

New technologies used in the study of human melanoma

The amount of information on tumor biology has expanded enormously, essentially due to the completion of the human genome sequencing and to the application of new technologies that represent an exciting breakthrough in molecular analysis. Often these data spring from experimental procedures, such as a serial analysis of gene expression (SAGE) and DNA microarrays, which cannot be defined as hypothesis-driven: it may appear to be a "brute force" approach through which no information can be directly generated concerning the specific functions of selected genes in a definite context. However, interesting results are fruitfully generated, and thus it is important to consider the enormous potential these new technologies possess and to learn how to apply this novel form of knowledge in the emerging field of molecular medicine. This review, after a limited outline regarding several classic aspects of human cutaneous melanoma biology, genetics, and clinical approaches, will focus on the proficient use of up-to-date technologies in the study of the neoplastic disease and on their capability to provide effective support to conventional approaches in melanoma diagnosis, prognosis, and treatment.

Mucin profiles in signet-ring cell carcinoma

CONTEXT

Signet-ring cell carcinoma (SRCC) is a poorly differentiated mucin-producing adenocarcinoma that may arise from many different organs, but all SRCCs share identical morphology. It is not possible to differentiate sites of origin for metastatic SRCC based on morphology alone. Mucins are high-molecular-weight glycoproteins differentially expressed in glandular epithelia and in adenocarcinomas.

OBJECTIVE

To identify mucin profiles of primary and metastatic SRCCs using immunohistochemistry to determine whether mucin staining could help distinguish sites of origin.

DESIGN

Forty-seven SRCCs, including 38 primary (21 stomach, 11 colorectum, and 6 breast) and 9 metastases from these primary sites were retrieved from archival files. Consecutive tissue sections were immunostained with monoclonal antibodies against MUC1, MUC2, MUC4, MUC5AC (MUC5), and MUC6 on separate slides. Cytoplasmic staining was scored based on proportion of positive tumor cells as follows: 0+ (<5%), 1+ (5%-25%), 2+ (26%-50%), and 3+ (>50%). Mucin profiles were recorded as MUC+, MUCv, and MUC- for consistent, variable, and negative expression, respectively.

RESULTS

The mucin profiles for gastric, colorectum, and breast SRCCs are MUC1.2.4.5.6v, MUC2.4+/MUC5v/ MUC1.6-, and MUC1+/MUC2.5.6v/MUC4-, respectively. Mucin profiles of metastatic cases shared profiles with their respective primaries.

CONCLUSIONS

Signet-ring cell carcinomas of the stomach, colorectum, and breast have distinct mucin expression patterns that are maintained in metastases. Mucin profiling may be useful to identify the origin of a metastatic SRCC of unknown primary.

Primary signet ring cell carcinoma of the prostate: report and review of 42 cases

We report a case of primary signet ring cell carcinoma of the prostate in a 75-year-old man. Serum prostate specific antigen (PSA) level at presentation was 9.3 ng/mL. The tumor was confined within the right prostate lobe and the patient was treated with neoadjuvant hormonal therapy and radical prostatectomy. He was alive with no evidence of disease 12 months after surgery. None of the tumor was stained with periodic acid-Schiff and Alcian blue. Immunohistochemically, the tumor was positive for PSA and prostatic acid phosphatase and negative for carcinoembryonic antigen. We reviewed 41 previously reported cases of signet ring cell carcinoma of the prostate, examining both histopathological and clinical information.

Unusual subtypes of prostate cancer

The vast majority of prostatic tumors developing in adult males are adenocarcinomas. For the most part, variations in histology have not received specific designations and, from a practical approach, have had any specific prognostic implications handled through application of the Gleason grading system. Nonetheless, some of the adenocarcinoma variants have specific clinical features and differential diagnoses. Furthermore, there has been some controversy regarding the appropriate application of the Gleason grading scheme in these tumors. In addition, there are carcinomas that are in fact not adenocarcinomas and that should be kept as distinct entities. In this paper, the histologic variants of adenocarcinoma are reviewed with emphasis on clinicopathologic features and the clinical relevance of these subtypes. Other carcinomas that occur in the prostate gland are also discussed again with a focus on the clinicopathologic characteristics.

Potent phagocytic activity discriminates metastatic and primary human malignant melanomas: a key role of ezrin

Features of phagocytosis have been observed in human tumors, but the phagocytic apparatus of tumor cells and the mechanism(s) underlying this phenomenon have yet to be defined. To address the phenomenon of phagocytosis, its underlying mechanism(s), and its possible role in tumor biology, we used human melanoma cells as a prototypic model. Our results showed that a process of phagocytosis of apoptotic cells occurs in vivo in human melanoma. This finding was consistent with evidence that human melanoma cells in vitro express all of the known lysosomal and phagocytic markers on their cytoplasmic vesicles and that a process of phagocytosis occurs in these vesicles. However, exclusively human melanoma cells deriving from metastatic lesions possess an efficient phagocytic machinery responsible for a macrophage-like activity against latex beads, yeast, and apoptotic cells of different origins, which was comparable to that of human primary macrophages. Moreover, the actin-binding protein ezrin was expressed on phagocytic vacuoles of melanoma cells and of cells deriving from a human adenocarcinoma; both treatment with cytochalasin B and specific inhibition of ezrin synthesis strongly affected the phagocytic activity of melanoma cells. This suggests that the association with the actin cytoskeleton is a crucial requirement for the development of this phenomenon. Hence our data provide evidence for a potent phagocytic activity exerted by metastatic melanoma cells possibly involved in determining the level of aggressiveness of human melanoma. This suggests that the assessment of phagocytic activity may be exploited as a new tool to evaluate the malignancy of human melanoma. Moreover, our data suggest that gene therapy or drug treatments aimed at inhibiting actin assembly to the phagosomal membranes may be proposed as a new strategy for the control of tumor aggressiveness.

Prostate mucinous adenocarcinoma with signet ring cell

Prostate mucinous adenocarcinoma with signet ring cell is a rare neoplasm with only 11 cases reported to date. We present the 12th case of prostate mucinous adenocarcinoma with signet ring cell. The case was detected incidentally as a result of a biopsy taken from a lesion in the prostatic urethra during a urethrocystoscopy of a 47-year-old male patient who underwent an internal urethrotomy operation due to urethrostenosis. Endoscopic examination showed a loose, spongy, gray-white structure covering the prostatic urethra, especially the right lobe of the prostate. The diagnosis resulting from the pathological examination of the biopsy was prostate mucinous adenocarcinoma with signet ring cell. A total of 50 Gy radiotherapy was applied to the patient. In the 27th month of follow-up after treatment, thoracoabdominal computed tomography, bone scintigraphy, and tumor markers (PSA, CEA and CA19-9) were found to be normal.

Exaggerated signet-ring cell change in stromal nodule of prostate: a pseudoneoplastic proliferation

A stromal nodule of the prostate was incidentally identified in a simple prostatectomy specimen from a 66-year-old man with benign prostatic hyperplasia. Microscopically, the nodule consisted of short spindly cells with bland nuclear features. Many of the cells in the nodule, however, contained a large, clear cytoplasmic vacuole that displaced and indented the nucleus, generating signet-ring cell morphology. Immunohistochemically, these cells were strongly positive for vimentin and weakly positive for desmin, suggesting a myofibroblastic nature. Further immunostains demonstrated the cells to be negative for cytokeratins and prostate-specific antigen, excluding the possibility of signet-ring cell carcinoma. The cytoplasmic vacuoles also stained negative for mucin production. Electron microscopy revealed no intracytoplasmic lumina. Notably, thermal effect or other signs of cellular injury, frequently associated with signet-ring cell change seen in prostate specimens obtained by transurethral resection and needle biopsy, were not appreciated in this stromal nodule. This case demonstrates that signet-ring cell change may occur in benign, hyperplastic, prostatic stromal cells in the absence of cellular damage.

Primary signet ring cell carcinoma of female urethra

A 69-year-old woman presented with difficulty in urination and bloody fluid discharge from the urethra. Based upon a diagnosis of primary urethral carcinoma, she underwent total cysto-urethrectomy and hysterectomy with pelvic lymph node dissection and urinary diversion of ileal conduit. Microscopically, the tumor was composed of mucinous adenocarcinoma and signet ring cell carcinoma. There was no recurrence 17 months after the surgery.