Rare perianal extramammary Paget disease successfully treated using topical Imiquimod therapy

Perianal Paget's-an aggressive disease

AIM

Perianal Paget's disease (PAPD) is a rare disorder with a predisposition to anal and colorectal malignancies and an unclear prognosis. Our previous 25-year series demonstrated a non-aggressive nature. This study aims to describe our updated institutional experience.

METHODS

This is a retrospective review of all patients diagnosed with primary PAPD from 1991 to 2021. A prospectively maintained institutional database was searched which included demographics, clinical and pathological manifestations, treatment methods, recurrence, oncological outcome and mortality.

RESULTS

Thirty patients were diagnosed with PAPD. Fifteen were women (50%); the average age at diagnosis was 71 ± 10.7 years, and the average lesion size was 3.7 ± 2.6 cm. At diagnosis, 12 (40%) were harbouring invasive anal adenocarcinoma. Eight (27%) developed adenocarcinomas concurrent with PAPD recurrence at a mean interval of 9 ± 4.4 years (range 1.9-14.8). The Kaplan-Meier curve estimated overall survival of 93%, 86%, 82%, 65% and 56% at 1, 3, 5, 10 and 15 years, respectively. Median survival was 16 years. Six (20%) had disease-related mortality. Initially, nine (30%) were treated with abdominoperineal resection (APR), 15 (50%) underwent local resection, three (10%) were treated with radiotherapy, two (7%) received only topical therapy and one (3%) chose observation. Fifteen (50%) experienced recurrence of PAPD, two after undergoing APR. Five (17%) had persistent disease until death. Only 10 (33%) did not experience PAPD recurrence, seven of whom underwent APR. The mean follow-up time was 9.2 ± 6.2 years.

CONCLUSIONS

Perianal Paget's disease is an aggressive entity with high rates of synchronous anal adenocarcinoma at diagnosis and development of metachronous adenocarcinoma later in life.

Perianal Paget's disease: a clinicopathological and immunohistochemical study of 13 cases

BACKGROUND

Perianal Paget's disease (PPD) is rare and mostly described in clinical literature as case reports or small series.

METHODS

We investigated the clinicopathologic and immunohistochemical features of PPD in a total of 13 cases retrieved from multiple academic institutions.

RESULTS

The median age at diagnosis was 75 (range 50-86) years. Males were predominant with a male to female ratio of 2.25:1. Four (30.8%) cases were classified as primary PPD due to lack of synchronous or metachronous underlying malignancies, while nine (69.2%) were classified as secondary PPD with concurrent invasive adenocarcinoma (n = 8) or tubular adenoma with high-grade dysplasia (n = 1). Immunohistochemically, there is no differential expression of CK7 or CK20 in Paget's cells between primary and secondary PPD; however, GCDFP-15 was only positive in primary PPD (3/3 vs. 0/6, P = 0.012), while CDX2 was only positive in secondary PPD (0/3 vs. 7/7, P = 0.008), suggesting different cell origin. All patients received local surgical resection with or without adjuvant therapy. After a median follow-up of 47 months, one patient with secondary PPD (7.7%) died of disease progression from underlying adenocarcinoma.

CONCLUSIONS

PPD occurs in elderly patients with male predominance and is frequently associated with underlying malignancies. Differential expression of CDX2 and GCDFP-15 may help distinguishing primary vs. secondary PPD, which is important for management as the presence of an underlying malignancy impacts clinical course and prognosis. Surgical excision remains the major treatment strategy for PPD. Long-term follow-up is required to monitor the disease recurrence and metastasis.

Anal canal adenocarcinoma with pagetoid spread and inguinal lymph node metastasis treated with preoperative chemoradiotherapy: A case report

Perianal Paget's disease is a rare condition, which is not usually accompanied by cancer. Here, a case of anal canal carcinoma with pagetoid spread and inguinal lymph node metastasis, which exhibited a significant response to preoperative chemoradiotherapy (CRT), is presented. A 58-year-old woman was admitted to The University of Tokyo Hospital with a complaint of discomfort around the anus. Physical examination revealed an erythematous inflamed skin lesion in the perianal region and a tumor of 15 mm in diameter detected on palpation in the left inguinal region, which was diagnosed as metastatic adenocarcinoma by excisional biopsy. Colonoscopy revealed moderately differentiated adenocarcinoma of 15 mm in diameter in the anal canal. Skin biopsy of the perianal region revealed an infiltration of pagetoid cells, which were positive for cytokeratin 7, and negative for cytokeratin 20 and gross cystic disease fluid protein 15. Based on these results, the patient was diagnosed as having anal canal adenocarcinoma with pagetoid spread. The patient received preoperative CRT including the bilateral inguinal region. After CRT, robotic-assisted laparoscopic abdominoperineal resection was performed. The macroscopic findings of the surgical specimen confirmed the formation of a scar as a result of the preoperative CRT. Microscopic examination of the anal tumor revealed no residual carcinoma or lymph node metastasis. In conclusion, this case may suggest the potential applicability of preoperative CRT for the local control of anal canal carcinoma with pagetoid spread.