Genetic analysis for mucinous ovarian carcinoma with infiltrative and expansile invasion and mucinous borderline tumor: a retrospective analysis

A giant ovarian atypical proliferative mucinous tumor in a young adult: A rare case report and review of the literature

INTRODUCTION AND IMPORTANCE

Ovarian atypical proliferative mucinous tumor (APMT) is a low-malignant or borderline tumor that originates from the ovary's surface epithelium. This tumor can grow to a massive size, causing abdominal distention, which can result in a variety of compression symptoms if it is not discovered early.

CASE PRESENTATION

A 23-year-old female presented with a chronic, gradually developing abdominal distention that had been persistent for a year. A large peritoneal cyst was suggested by an abdominal CT scan. A massive left ovarian tumor was discovered during an exploratory laparotomy. Salpingo-oophorectomy was performed, and the pathology report confirmed the diagnosis of APMT. No recurrence has been observed during a year of follow-up.

CLINICAL DISCUSSION

Diagnosis of ovarian APMBT involves clinical assessment, history, and symptoms of the patient. Imaging studies are useful in identifying these lesions. Ultrasound demonstrates a large, unilocular or multilocular cystic mass with thin septations. Further characterization requires an MRI or CT scan. Serum tumor markers such as CEA, CA-125, and β-hCG are helpful in diagnosing these lesions. The definitive diagnosis requires histopathological examination. Unilateral salpingo-oophorectomy is the mainstay of treatment. Adjuvant therapy is not required. Lifelong follow-up is essential, especially for fertility-sparing surgeries due to recurrence risk.

CONCLUSION

Due to the substantial overlap of clinicopathological characteristics with other tumors, accurate diagnosis of APMT can be difficult. Large tumor sizes may cause alarm for other pathologies such as cancer. The attending physician should be reassured with the imaging examinations, and the diagnosis is confirmed by the histopathology examination.

Infiltrative pattern of invasion is independently associated with shorter survival and desmoplastic stroma markers FAP and THBS2 in mucinous ovarian carcinoma

AIMS

Mucinous ovarian carcinoma (MOC) is a rare ovarian cancer histotype with generally good prognosis when diagnosed at an early stage. However, MOC with the infiltrative pattern of invasion has a worse prognosis, although to date studies have not been large enough to control for covariables. Data on reproducibility of classifying the invasion pattern are limited, as are molecular correlates for infiltrative invasion. We hypothesized that the invasion pattern would be associated with an aberrant tumour microenvironment.

METHODS AND RESULTS

Four subspecialty pathologists assessed interobserver reproducibility of the pattern of invasion in 134 MOC. Immunohistochemistry on fibroblast activation protein (FAP) and THBS2 was performed on 98 cases. Association with survival was tested using Cox regression. The average interobserver agreement for the infiltrative pattern was moderate (kappa 0.60, agreement 86.3%). After reproducibility review, 24/134 MOC (18%) were determined to have the infiltrative pattern and this was associated with a higher risk of death, independent of FIGO stage, grade, and patient age in a time-dependent manner (hazard ratio [HR] = 10.2, 95% confidence interval [CI] 3.0-34.5). High stromal expression of FAP and THBS2 was more common in infiltrative MOC (FAP: 60%, THBS2: 58%, both P < 0.001) and associated with survival (multivariate HR for FAP: 1.5 [95% CI 1.1-2.1] and THBS2: 1.91 [95% CI 1.1-3.2]).

CONCLUSIONS

The pattern of invasion should be included in reporting for MOC due to the strong prognostic implications. We highlight the histological features that should be considered to improve reproducibility. FAP and THBS2 are associated with infiltrative invasion in MOC.