2. Faculty of Laboratory Sciences, Elzaim Elazhari University, Khartoum North, Sudan.
3. Faculty of Medicine, Ahfad University for Women, Omdurman, Sudan.
4. Faculty of Medicine, University of Khartoum, Khartoum, Sudan.
Oesophageal cancer is the eighth commonest form of cancer world-wide with variable incidence rates across different geographical regions. Squamous cell type is the commonest histological type in developing countries. This study aimed to determine the pathological subtypes of oesophageal cancer and the probable roles of some markers in the metastatic potential of uncommon subtypes. The study Proposal was approved by the institutional review board. Clinical data and histopathology results of 55 resection specimens from oesophageal cancer cases were reviewed. Two uncommon tumours, a basaloid squamous carcinoma and a squamous cell carcinoma that invaded the stomach were analyzed by immunohistochemistry for stemness and pathogenesis. All specimens received were stage T3N2 or T3N3 and had carbon pigment in the draining lymph nodes. The most common histological type was squamous cell carcinoma of different degrees of differentiation (74%). Adenocarcinoma was less common and was reported in 14.6% of the cases. The basaloid squamous carcinoma consisted of well differentiated squamous cells and basaloid spindle cells. Both the squamous and basaloid components were positive for P63. Basaloid cells were positive for CD44, weakly positive for OCT4 and negative for E-Cadherin. This part metastasised to regional lymph nodes. The oesophageal carcinoma that invaded the stomach was positive for CD44 but negative for E-Cadherin. The CD44 and E-Cadherin changes described in the basaloid squamous carcinoma were in the gastric component which metastasised to abdominal lymph nodes.
Conclusion: Squamous cell carcinoma of different degrees of differentiation is the commonest type of oesophageal cancer in Sudan with variations in male: female ratios. Over expression of CD44 and down regulation E-Cadherin are probably associated with aggressiveness and metastasis.
Keywords: Oesophageal cancer, squamous cell, pathogensis, Sudan