HPV-Related Retroperitoneal Squamous Cell Carcinoma of Unknown Primary: A Case Report

Case report: HPV related pelvic retroperitoneal squamous cell cancer of unknown primary presenting as ovary neoplasm

INTRODUCTION

Retroperitoneal tumors (RPTs) of the pelvis are rare and often present asymptomatically. We report a rare case of human papillomavirus (HPV)-related primary retroperitoneal squamous cell carcinoma (PRSCC) that was preoperatively misdiagnosed as adnexal cancer.

CASE PRESENTATION

A menopausal 59-year-old woman presented with right leg pain persisting for two months. Imaging revealed a heterogeneous lesion in the right adnexal area; however, the uterus and left ovary appeared normal. Laboratory tests showed slightly elevated levels of cancer 125 (CA 125) and squamous cell carcinoma (SCC) antigens. The patient underwent surgical staging for the suspected ovarian cancer. Intraoperatively, the bilateral adnexa and uterus appeared normal. A lesion identified in the right pelvic retroperitoneal cavity was resected and its pathological analysis revealed SCC and cervical intraepithelial neoplasia III (CIN III) and immunohistochemical expression of cyclin-dependent kinase inhibitor 2A (p16) in the cervix. HPV 16 was identified by a polymerase chain reaction (PCR). The patient chose not to undergo any additional postoperative treatment. Her leg pain disappeared the day after the procedure but recurred a year later. A new tumor was detected on computed tomography (CT) in the same area.

DISCUSSION

PRSCC is rare and can be misdiagnosed as a gynaecological neoplasm. HPV can migrate to the retroperitoneal space and act as a carcinogen in this location.

CONCLUSIONS

HPV infection may contribute to the development of PRSCC. Complete surgical resection, with adjuvant radiotherapy and chemotherapy, is a viable treatment approach.

HPV-related metastatic retroperitoneal pelvic squamous cell carcinoma of unknown primary origin in a patient previously treated for endometrial cancer

INTRODUCTION

Cancer of unknown primary (CUP) is metastatic disease with no identifiable site of origin. Retroperitoneal squamous cell carcinoma of unknown primary is extremely rare. There are limited reports regarding treatment recommendations and outcomes for women with this disease.

PRESENTATION OF CASE

Here we present the case of a woman with human papillomavirus (HPV)-related metastatic retroperitoneal pelvic squamous cell carcinoma of unknown primary previously treated for endometrial cancer as well as a review of the existing reports on this topic. Surgical removal of the tumor was performed, the treatment had effective immediate results.

DISCUSSION

There are a few reports describing CUPs in the retroperitoneal space. Most retroperitoneal tumors are asymptomatic and may be found incidentally during a regular examination, as in the case presented here. A full pelvic exam including inspection of the vulva, colposcopy and anoscopy should be performed, particularly in HPV-associated CUPs. Pathologic testing including immunohistochemistry and special staining and molecular testing of the tumor may be needed.

CONCLUSION

It is important to find the primary origin of cancer to treat it successfully. If the primary tumor cannot be identified, immunohistochemistry and molecular testing of the tumor may help identify the nature of malignant disease and help guide appropriate treatment.

A case of pelvic squamous cell carcinoma of unknown primary origin that responded well to radiotherapy and nivolumab

Squamous cell carcinoma of unknown primary origin in the pelvis is rare. We report a case of a 64-year-old woman with a large osteolytic squamous cell carcinoma of unknown primary origin in the pelvis that presented with p16 expression. The patient presented with leg pain and swelling and was admitted to our hospital. Computed tomography scans of the pelvis revealed a large osteolytic tumor. A computed tomography-guided needle biopsy was performed, and pathological examination revealed neoplastic cells with metastatic squamous cell carcinoma presenting with p16 expression. Despite a whole-body examination, tumor origin remained undetected. The patient was treated for this metastatic squamous cell carcinoma of unknown primary using palliative radiotherapy for hip pain and nivolumab. Remarkable reduction in the tumor marker levels and tumor size were obtained after therapy. Finally, partial remission and progression-free survival for more than 7 months were achieved. In conclusion, we experienced a rare case with a large p16-positive squamous cell carcinoma of unknown primary in pelvis, which responded well to radiotherapy and nivolumab.

Primary retroperitoneal squamous cell carcinoma: a literature review

PURPOSE

Retroperitoneal squamous cell carcinoma is an extremely rare histological variant of retroperitoneal tumors. The exact etiology and origin of the same is still unknown. To date, only a few case reports have been published in the literature. Due to rarity, standard treatment protocol is not available. The article aims to review the literature and treatment options available for this uncommon entity, based on available data.

METHODS

We searched the databases like PubMed, PubMed Central, Scopus, and Google Scholar with the keywords "Squamous cell carcinoma" and "retroperitoneal tumors". Peer-reviewed and recent articles were screened.

RESULTS

Seven relevant articles comprising 14 cases were found. Due to the small number of reports, tabulation of treatment details and outcome was done. Like the sarcoma variant, these tumors also present with a large mass in the abdomen and abdominal discomfort. Association with human papillomavirus appears to be the most common factor that gives rise to squamous histology.

CONCLUSION

Retroperitoneal SCC is an uncommonly diagnosed entity. Although no specific treatment guidelines exist for this uncommon malignancy; surgery followed by adjuvant or definitive radiotherapy with concurrent chemotherapy (in inoperable cases) seems a feasible option. Multicentre trials should be conducted for establishing definitive treatment strategies for this ailment.

A case of synchronous high-grade cervical intraepithelial neoplasia and metastatic squamous cell carcinomas of unknown primary in rectum

We report a case of synchronous high-grade cervical intraepithelial neoplasia (CIN) and metastatic squamous cell carcinomas (SCCs) of unknown primary in the rectum. A 74-year-old woman was diagnosed with CIN3 by biopsy of the uterine cervix. Magnetic resonance imaging showed two masses in the outer rectal wall. They were diagnosed as SCCs by transrectal biopsy from one mass. On surgical treatment, CIN3 and SCCs in the rectum were identified, respectively. Pathological analysis revealed that SCCs were observed in serosa of the rectum, not mucosa, indicating that these tumors were metastatic SCCs. Gene analysis showed HPV31-positive and TP53 mutation in CIN3, and HPV16-positive in rectal SCCs. Pretreatment examination did not detect the primary site of metastatic SCCs in the rectum. We diagnosed the patient with synchronous CIN3 and metastatic SCCs of unknown primary in the rectum. In this case, gene analysis was useful to clarify the relationship between CIN3 and SCCs.

Primary retroperitoneal squamous cell carcinoma: a case report with review of the literature

Squamous cell carcinoma originating in the retroperitoneal cavity is an exceedingly rare disease, and little is known about it. Here, we report the case of primary retroperitoneal squamous cell carcinoma. A 76-year-old gravida four para two woman with a history of hysterectomy for unknown reasons was referred to our hospital for an infant-head-sized multicystic pelvic mass. She was initially diagnosed with ovarian cancer Stage IIB, poorly differentiated carcinoma by exploratory laparotomy in which only a tumor biopsy was performed due to severe adhesion. She underwent 5 courses of combination chemotherapy with paclitaxel and carboplatin, which reduced the tumor from 14 to 6.5 cm. Interval debulking surgery proved that the tumor was in the retroperitoneal cavity and not associated with the ovaries. She was finally diagnosed with squamous cell carcinoma originating in the retroperitoneal cavity. Human papilloma virus type 16 was identified using polymerase chain reaction. Three more courses of paclitaxel and carboplatin were administered, and she has been without evidence of disease for 6 months. A comprehensive literature search identified seven similar cases of which four individuals had a history of abdominal hysterectomy. Four out of the seven cases were tested for the presence of P16, two for HPV; all the results were positive. These findings suggest that HPV could be the cause of squamous cell carcinoma on the pelvic peritoneum, and that past hysterectomy is a possible contributing factor.

Three cases of women with HPV-related squamous cell carcinoma of unknown primary in the pelvis and retroperitoneum: A case series

Background

Carcinoma of unknown primary (CUP) of the pelvis is a challenging entity for the oncologist. The role of human papilloma virus (HPV)/p16 in carcinogenesis and prognosis is more established in the head and neck than in the pelvis. In the case of an HPV positive occult primary of the pelvis the radiation therapy target coverage is not well established.

Case reports

Case#1: A 69-year-old female with a left retroperitoneal and pelvic mass was treated with chemoradiation to a dose of 45 Gy in 25 fractions to elective lymph node regions and simultaneous boost to FDG-avid lymph nodes to 55 Gy in 25 fractions. A post-treatment PET-CT showed complete response of disease now 7 months post treatment. Case#2: A 58-year-old female with a large left retroperitoneal pelvic mass was treated post-operatively with chemoradiation to 45 Gy in 25 fractions with a pelvic boost to 54 Gy. She is clinically and radiographically with no evidence of disease at 4 years. Case#3: A 47-year-old female with left sided retroperitoneal pelvic mass that declined therapy. She ultimately died of progressive disease at 1 year after diagnosis.

Conclusion

Cisplatin based chemoradiation is effective for treating HPV/p16 + pelvic squamous cell cancers of unknown primary as long as the mass, regional lymph nodes and high risk pelvic primary sites are adequately covered.

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Adds 3 cases of pelvic squamous cell carcinoma of unknown primary

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Similarities between pelvic and head and neck squamous cell of unknown primary

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Radiation to highest risk sites of primary disease important

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Prognosis not as bad as previously shown with aggressive chemoradiation