Peritoneal melanosis combined with serous cystadenoma of the ovary: a case report and literature review

Peritoneal melanosis associated with serous carcinoma of the ovary: A case report and literature review

Introduction

Melanosis peritonei is an exceptionally benign condition of uncertain origin marked by the deposition of dark pigments on the peritoneal cavity. It's usually associated with other abnormalities and must be differentiated from metastatic melanoma.

Case presentation

We report this case of a 67-year-old female presented for abdominal distension for 16 months. Abdomino-pelvic CT scan showed a right pelvic ovarian mass locally developed with the presence of peritoneal ascites. We performed initially an exploratory laparotomy confirmed the radiological constatations with biopsies of the peritoneal carcinosis. Histologic analysis showed a poorly differentiated carcinomatous cell. The patient benefited from neoadjuvant chemotherapy then an abdomino-pelvic CT scan of control was performed showing the reduction in size of the ovarian mass and dispersion of the abdominal effusion. A second laparotomy was carried out and the exploration showed the appearance of dark nodules on the peritoneum. Hysterectomy associated with appendectomy and omentectomy with biopsy of the dark nodules was performed. Pathological study and immunohistochemical staining confirmed the diagnosis of benign peritoneal melanosis associated with serous carcinoma of the ovary.

Discussion

Peritoneal melanosis is a rare condition with only 18 cases reported on the English literature. It is often associated with other conditions. The origin of this lesion still unclear although some hypotheses were reported. The main differential diagnosis is metastatic melanoma with very poor prognosis.

Conclusion

benign peritoneal melanosis is a rare condition. Its management depends essentially on the associated disease.

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Melanosis peritonei is an exceptionally benign condition of uncertain origin.

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Melanosis peritonei usually affects women between the ages of 18 and 28 years old.

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Melanosis peritonei is mostly associated with other disorders such as desmoid ovarian cyst, enteric duplication cyst, gastric triplication, and ovarian cystadenomas.

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The main differential diagnosis of melanosis peritonei is metastatic melanoma.

Melanosis Peritonei Associated With Adenocarcinoma of the Sigmoid Colon

Melanosis peritonei is an unusual and uncommon condition characterized by pigment deposition in the peritoneum. It is usually associated with other conditions. During a right inguinal hernia open repair for an 86-year-old gentleman, widespread black spots were observed on the hernial sac. After appropriate histopathological and immunohistochemical studies, the diagnosis of melanosis peritonei was established. The past medical history of the patient included an endoscopic excision of a sigmoid polyp which was found to be an adenocarcinoma with <1mm clearance margin on histopathology. Being recognized as an extremely rare condition, melanosis peritonei should be differentiated from other conditions including metastatic melanoma.

Peritoneal melanosis associated with metastatic melanoma previously treated with targeted and immune checkpoint inhibitor therapy

Peritoneal melanosis is an uncommon benign condition, the pathophysiology of which is unclear. Macroscopically, it appears as diffuse dark brown or black pigmentation within the peritoneum, mimicking more sinister conditions such as metastatic melanoma. It has been described in a variety of contexts, but only exceedingly rarely in association with metastatic melanoma, with only two previous published case reports. We present a case of peritoneal melanosis associated with metastatic melanoma involving the spleen, previously treated with targeted and immune checkpoint inhibitor therapy. With increasing reports of melanoma regression manifesting as cutaneous tumorous melanosis in patients treated with immune checkpoint inhibitors, we postulate that, similarly, immunotherapy and tumour regression might have a role to play in the pathogenesis of the peritoneal pigmentation in this case.

Ovarian Sex Cord-stromal Tumors With Melanin Pigment: Report of a Previously Undescribed Phenomenon

We report 2 ovarian sex cord-stromal tumors, a luteinized adult granulosa cell tumor and a cellular fibroma, with melanin pigment. These occurred in 44 and 61-yr-old patients, respectively. As far as we are aware, melanin pigment has not been described previously in an ovarian sex cord-stromal tumor, although it has been reported in a testicular Sertoli cell tumor. We review ovarian neoplasms containing melanin pigment.

Selected Case From the Arkadi M. Rywlin International Pathology Slide Club: Peritoneal Lipofuscinosis and Deciduosis in Pregnancy

Peritoneal lipofuscinosis is a very rarely recognized condition occurring during pregnancy characterized by brown pigmentation of the omentum and peritoneum, a decidual reaction and benign mesothelial cells. The iron negative pigment, which is likely to be confused with hemosiderin in the hematoxylin and eosin stain, is lipofuscin. The seminar case, apparently the third published, arose in a 37-year-old woman who presented in October 2015 at 24 weeks pregnancy with abdominal pain. Investigations revealed a ruptured left ovarian cyst and rising serum carcinoembryonic antige levels. At laparotomy, there was no free intraperitoneal blood but the omentum and uterine serosa were black. Histology showed lipofuscinosis and a decidual reaction. The patient delivered a normal baby in February 2016 and was clinically well after delivery. A left ovarian endometriotic cyst was removed in February 2017. The patient made a good recovery with no clinically apparent symptoms from the liposuscinosis. We postulate that the endometriotic cyst had ruptured and released blood into the peritoneal cavity in 2015. The iron from the red cells breakdown was then rapidly resorbed because of the pregnancy requirements for iron, leaving lipofuscin in peritoneal macrophages.

Secondary tumors and tumorlike lesions of the peritoneal cavity: imaging features with pathologic correlation

Tumors and tumorlike lesions that secondarily involve the mesothelial or submesothelial layers of the peritoneum are a diverse group of disorders that range in biologic behavior from benign to highly malignant. The anatomy of peritoneal ligaments and mesenteries and the normal circulation of peritoneal fluid dictate location and distribution of these diseases within the peritoneal cavity. Peritoneal carcinomatosis is the most common secondary tumor to affect the peritoneal cavity. When it arises from carcinomas of the gastrointestinal tract or ovary, the prognosis is grave. However, when low-grade mucinous adenocarcinoma of the appendix spreads to the peritoneal cavity, the consequence is typically pseudomyxoma peritonei, which is a clinical syndrome, characterized by recurrent and recalcitrant voluminous mucinous ascites due to surface growth on the peritoneum without significant invasion of underlying tissues. Carcinomas from elsewhere in the body, as well as lymphomas and sarcomas, may also produce diffuse peritoneal metastasis. Granulomatous peritonitis is the consequence of disseminated infection such as tuberculosis or histoplasmosis, foreign materials, or rupture of a tumor or hollow viscus. Finally, a group of benign miscellaneous conditions that range from common disorders such as endometriosis and splenosis to very rare conditions such as gliomatosis peritonei and melanosis may also affect the peritoneum diffusely. Secondary tumors and tumorlike lesions of the peritoneum have overlapping imaging features when compared with each other and primary peritoneal tumors. Knowledge of peritoneal anatomy, normal fluid circulation within the peritoneal cavity, and clinical and pathologic features of secondary peritoneal lesions is essential for identification of these lesions.