Organ preservation in anorectal melanoma: A tempting challenge-a case report.

Melanoma arising from melanocytes is an uncommon neoplastic lesion, with rare occurrences in anorectal mucosa. While mucosal melanomas constitute a small portion of all melanomas, anorectal cases are even rarer and present with aggressive behavior and poor prognosis. Surgical management is central, with evolving debates regarding optimal approaches. We present a case of a 60-year-old woman with anorectal melanoma. She complained of rectal bleeding and weight loss. Clinical examination and pelvic magnetic resonance imaging revealed a 3-cm budding lesion on the anterior rectal wall. Colonoscopy identified a pedunculated anorectal tumor of 3 cm, situated 4 cm from the anal margin. A biopsy led us to a malignant lesion: anorectal melanoma. Pelvic imaging displayed a localized tumor, prompting wide local excision with millimetric negative margins. These resection margins were estimated insufficient, even in front of R0 resection. Thus, and after multidisciplinary discussion, we opted for abdominoperineal resection after wide local excision. Lymph nodes were biopsied, confirming no residual tumor. Follow-up exhibited no recurrence at 1 year. Our case emphasizes the pivotal role of surgical strategy in managing anorectal melanoma, challenging the paradigm of organ preservation. Despite therapeutic progress, surgery remains integral, contributing to improved outcomes and addressing the metastatic potential inherent to this disease.

Verrucous Carcinoma Arising in an Extended Giant Condyloma Acuminatum.

A 43-year-old heterosexual Tunisian man presented to the dermatology department with complaints of a genital friable mass. He had a past medical history of chronic hepatitis B. He was married and had a history of multiple sexual partners. The lesion had been present for over 10 years and gradually increased in size, disfiguring his genitalia. It had a major impact on his quality of life, preventing sexual intercourse and resulting in poor personal hygiene. On physical examination, the vegetative lesion presented as a giant cauliflower-like tumor (Figure 1) with a foul smell. The tumor involved the left inguinal region, the suprapubic genitalia, and was encircling the entire penile shaft. He also had inguinal lymphadenopathies. Under local anesthesia, a skin biopsy of the vegetative tumor was performed and sent for histopathologic examination. It revealed an exophytic epithelial tumor with papillomatosis, marked acanthosis, and many koilocytes, especially in the superficial layers of the epidermis. These signs along with the preservation of regular cytology were consistent with the diagnosis of condyloma acuminatum (Figure 2a). The histologic examination also showed clusters of atypical keratinocytes with high mitotic activity and keratinization, suggesting nests of squamous cell carcinoma (SCC) (Figure 2b and 2c). DNA-polymerase chain reaction (PCR) marker for Human papilloma virus (HPV) stains 11 was positive. Serology for hepatitis C, HIV, and syphilis non-reactive. Computed tomography scan of the abdomen and pelvis showed inguinal lymphadenopathies. The patient was referred to the oncologist for radiotherapy to reduce the size of the tumor followed by surgery. (SKINmed. 2023;21:53-54).

Primary hydatid cyst of the small intestine masquerading as intestinal duplication in a child.

Hydatid disease or hydatidosis is a worldwide zoonosis disease caused by the tapeworm of Echinococcus granulosus and still widely endemic in Tunisia especially in rural areas where the sheep-dog cycle is dominant. It is an important public health problem in the pediatric age group causing significant morbidity and mortality. We report a case of primary hydatid cyst of the small intestine in a child and we want to highlight the difficulty that we meet in the diagnosis despite the contribution of imaging.

A Red Nodule on the Face.

An otherwise healthy 34-year-old man presented to our clinic with a small nonhealing, tender papule that had appeared on his face 9 months previously. His family history and past medical history were unremarkable. There was no history of trauma. Cutaneous examination revealed a small erythematous papule 0.5 cm in diameter on the left preauricular region (Figure 1). There was no regional lymphadenopathy, and he was in a generally good condition.

KRAS and NRAS pyrosequencing screening in Tunisian colorectal cancer patients in 2015.

BACKGROUND: Mutations in KRAS and NRAS often result in constitutive activation of RAS in the epidermal growth factor receptor (EGFR) signaling pathway. Mutations in KRAS exon 2 (codon 12-13) predict resistance to anti-EGFR targeted therapy in patients with metastatic colorectal carcinoma (mCRC). However, it's currently known that a significant proportion of mCRC have RAS mutations outside KRAS exon 2, particularly in exons 3 and 4 of KRAS and exons 2, 3 and 4 of NRAS. No data about RAS mutations outside KRAS exon 2 are available for Tunisian mCRC. The aim of this study was to analyze RAS, using pyrosequencing, in nine hotspots mutations in Tunisian patients with mCRC. METHODS: A series of 131 mCRC was enrolled. Nine hotspots sites mutations of KRAS and NRAS were analyzed (KRAS: codons 12-13, codons 59-61, codon 117 and codon 146, NRAS: codons 12-13, codon 59, codon 61, codon 117 and codon 146) using Therascreen KRAS and RAS extension pyrosequencing kits. RESULTS: Analysis was successful in 129 cases (98.5%). Mutations were observed in 97 cases (75.2%) dominated by those in KRAS exon 2 (86.6%). KRAS G12V was the most dominated mutation, observed in 25 cases (25.8%), and followed by KRAS G12S and KRAS G12D, each in 17 cases (17.5%). Mutations outside of KRAS exon 2 presented 13.4% of mutated cases and almost a third (28.8%) of KRAS exon 2 wild type mCRC. Among those, 9 cases (69.3%) carried mutations in NRAS exons 2, 3 and 4 and 4 cases (30.7%) in KRAS exons 3 and 4. CONCLUSIONS: RAS mutations outside exon 2 of KRAS should be included in routine practice, since they predict also response to anti-EGFR. That would make certain these patients benefit from appropriate testing and treatment. In addition unjustified expenses of anti-EGFR targeted therapy could be avoided.

Ampullary and pancreatic adenocarcinoma-a comparative study.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) and ampullary adenocarcinoma (AAC) are 2 gastrointestinal cancers that share overlapping symptoms. Although some studies have proposed the hypothesis of differences in pathogenesis and prognosis in these 2 cancers; they remain treated similarly. The classification of AAC into three subtypes [pancreatobiliary (PB), intestinal (IT) and mixed (M)] is especially crucial for the 3 axes of patients management (diagnosis, prognosis and therapy). Some studies suggest that PB subtype pathogenesis is comparable to PDAC. The objective of this study was to conduct a comparative analysis between PDAC and AAC; notably PB subtype; via mutational status analysis of 3 oncogenes (KRAS, NRAS and BRAF) hoping to consolidate AAC biology understanding. METHODS: Nine hot spot mutation sites of KRAS, NRAS and BRAF were analysed using pyrosequencing in 39 PDAC and 21 AAC from Tunisian patients. Comparative study was performed using SPSS software. RESULTS: Mutations in oncogenes were detected in almost 43% of AAC, especially in PB (47%) and 95% of PDAC. KRAS was the most mutated oncogene. There were statistical significant differences between PDAC and AAC in tumor differentiation (P<0.001), perineural invasion (P<0.001), vascular emboli (P=0.001), T stage (P=0.007), N stage (P=0.001) and mutational status (P<0.001). When comparing PDAC and PB subtype, there were also significant differences in tumor size (P=0.001), tumor differentiation (P<0.001), perineural invasion (P<0.001), vascular emboli (P=0.001), T stage (P=0.033), N stage (P<0.001) and mutational status (P<0.001). CONCLUSIONS: AAC even PB subtype is different from PDAC. We think that these different tumor types require highly individualized therapy guided by their histomolecular characteristics and that we should stop diagnosing and treating them as a unique entity.

Anguillulosis: circumstances of infestation and evolution towards the malignant form.

INTRODUCTION: Anguillulosis is a ubiquitous digestive parasitosis. Rare in Tunisia, it is due to a round worm, strongyloid stercoralis, whose natural lodging is the duodeno-jejunal mucosa. Its malignant form is rare but it represents a potentially life-threatening disease. AIM: We report a case of malignant anguillulosis occurring in a context of immunosuppression. OBSERVATION: The case we report is about a 46-year-old man treated by a long-term corticosteroid therapy for Takayasu disease. He was hospitalized for an acute digestive syndrome. Biopsies were performed but the evolution was rapidly marked by multiorgan failure, sepsis and death of the patient. Histological analysis of the digestive biopsies concluded to an oeso-gastroduodenal anguillulosis. CONCLUSION: Anguillulosis is a rare parasitosis but it can pose a health problem especially in its malignant form wich can be a life-threatening.

KRAS, NRAS and BRAF analysis of ampullary adenocarcinoma classified using CK7, CK20, MUC1 and MUC2.

BACKGROUND: Ampullary carcinomas are rare and dominated by adenocarcinomas. They account for only 0.5% of all gastrointestinal malignancies. Ampullary adenocarcinoma (AAC) with pancreaticobiliary (PB) histology has a worse outcome than that with intestinal (IT) histology. The mixed subtype contains the two epitheliums. This subclassification remains a challenge for pathologists and induces a reasonable level of disagreement. Genetic features of these subtypes are unclear. In this study, we aimed to reclassify AAC cases then to evaluate differences in prognostic, pathological and molecular parameters including mutational status of three oncogenes between these subtypes. METHODS: AACs from 21 Tunisian patients were used in this study. Reclassification was made based on histology and immunohistochemistry (IHC) using CK7, CK20, MUC1 and MUC2. Mutational analysis included the pyrosequencing of KRAS, NRAS and BRAF. RESULTS: Fifteen cases were PB subtype, 2 cases were IT subtype and 4 cases were mixed subtype. CK20 and MUC2 were associated with N stage, MUC1 and histomolecular subtype with T stage. Nine cases were mutated and 12 were wild-type. Eight cases were KRAS mutated (5 G12D and 3 G12V). Only 1 case was NRAS mutated (G12D). No BRAF mutation was found. Genetic alterations didn't influence prognostic factors. CONCLUSIONS: We validate the prognostic utility of AAC histomolecular classification.