Patterns of pathologic lymph nodes in anal cancer: a PET-CT-based analysis with implications for radiotherapy treatment volumes

Background This study investigates the patterns of PET-positive lymph nodes (LNs) in anal cancer. The aim was to provide information that could inform future anal cancer radiotherapy contouring guidelines. Methods The baseline [18F]-FDG PET-CTs of 190 consecutive anal cancer patients were retrospectively assessed. LNs with a Deauville score (DS) of ≥3 were defined as PET-positive. Each PET-positive LN was allocated to a LN region and a LN sub-region; they were then mapped on a standard anatomy reference CT. The association between primary tumor localization and PET-positive LNs in different regions were analyzed. Results PET-positive LNs (n = 412) were identified in 103 of 190 patients (54%). Compared to anal canal tumors with extension into the rectum, anal canal tumors with perianal extension more often had inguinal (P < 0.001) and less often perirectal (P < 0.001) and internal iliac (P < 0.001) PET-positive LNs. Forty-two patients had PET-positive LNs confined to a solitary region, corresponding to first echelon nodes. The most common solitary LN region was inguinal (25 of 42; 60%) followed by perirectal (26%), internal iliac (10%), and external iliac (2%). No PET-positive LNs were identified in the ischiorectal fossa or in the inguinal area located posterolateral to deep vessels. Skip metastases above the bottom of the sacroiliac joint were quite rare. Most external iliac PET-positive LNs were located posterior to the external iliac vein; only one was located in the lateral external iliac sub-region. Conclusions The results support some specific modifications to the elective clinical target volume (CTV) in anal cancer. These changes would lead to reduced volumes of normal tissue being irradiated, which could contribute to a reduction in radiation side-effects.

Total scrotal reconstruction following Fournier’s gangrene with bilateral prelaminated superior medial thigh flaps

The patient is a 45-year-old man diagnosed with Fournier’s gangrene and underwent treatment for septic shock, broad-spectrum antibiotic therapy and extensive surgical debridement of perineum, including total scrotectomy, ischiorectal fossa, abdomen and left superior thigh and flank. The patient required multiple staged complex reconstruction of the scrotum utilising prelaminated superior medial thigh flaps with use of dermal matrix, split-thickness skin grafting and pedicled gracilis muscle flap for coverage of the ischiorectal wound. The patient had full recovery and followed up 1 year postoperatively. This report discusses our technique for total scrotal reconstruction and provides review of surgical reconstructive techniques for wounds due to Fournier’s gangrene.

Aggressive angiomyxoma of the ischioanal fossa in a post-menopausal woman

Aggressive angiomyxoma is a rare mesenchymal tumour, primarily arising in the soft tissue of the pelvis and perineum in women of reproductive age. There is a paucity of evidence on optimal management because of the rarity of these tumours, but the consensus has been for surgical excision. We present the case of a 65-year-old woman who was admitted with left-sided buttock pain and initially diagnosed with a perianal abscess. She underwent examination under anaesthesia rectum with surgical excision of the lesion, subsequent histopathological and immunochemical analysis was suggestive of aggressive angiomyxoma. To complement our case report, we also present a literature review focusing on aggressive angiomyxoma in the ischioanal fossa (also known as the ischiorectal fossa) with only eight cases of primary aggressive angiomyxoma involving the ischioanal fossa documented to date. The primary aims of this case report and literature review are to familiarise clinicians with the clinical, histopathological and immunochemical features of these tumours, and to increase appreciation that despite the rarity of aggressive angiomyxoma, it might be considered in the differential diagnosis of ischioanal lesions.