He hails from Ogbomoso in Ogbomoso North Local Government Area of Oyo State. Born on 25th June 1962, he started his primary education at the Baptist Day School, Osupa, Ogbomoso in 1970. In 1973 he went to Dorowa Babuje in the then Benue Plateau State where he completed his primary seven in 1976. He thereafter proceeded to Federal Government College, Enugu between 1976 and 1981.
Doctor Adeniji had his University education at the University of Ife where he obtained a bachelor’s degree in Health Sciences in 1985. He had his Bachelor of Medicine, Bachelor of Surgery from the same University in 1989 which had then been renamed Obafemi Awolowo University, Ile-Ife. He did his housemanship with the Oyo State Hospitals Management Board and then proceeded for his National Youth Service Corp at the Institute of Health, Ahmadu Bello University Teaching Hospital, Zaria.
He started his postgraduate medical education in Pathology at the Department of Pathology, Ahmadu Bello University Teaching Hospital, Zaria in 1990. He crossed over to the Obafemi Awolowo University Teaching Hospitals Complex, Ile-Ife in 1991 and completed the program in 1995 to bag the Fellowship of the National Postgraduate Medical College in Pathology (FMCPath.). He worked briefly with the University of Calabar and the University of Calabar Teaching Hospital before moving over to University of Ilorin and University of Ilorin Teaching Hospital in 1996.
After passing the Part 1 fellowship program in 1993, he developed interest in cancer research with special interest in breast cancer. The Part 2 dissertation was on breast diseases with the title – “Pattern and histopathological features of breast diseases in Ile-Ife, Nigeria”. After doing appreciable work on various cancers locally, he established collaborative research programs with renowned cancer research centers in Europe and America and many of the collaborations are still on-going. One of the collaboration is with the Director of the Center for Clinical Cancer Genetics at the University of Chicago Medical Center, Prof. (Mrs.) Olufunmilayo I. Olopade. Title of the research is – “Genetic susceptibility to breast cancer in African population: study of paraffin-embedded breast cancer tissues from University of Ilorin Teaching Hospital, Ilorin, Nigeria”. Our center in Ilorin is one of the few centers selected in Africa for this multicenter study. In July 2009, he was invited to the National Cancer Institute in Bethesda, Maryland for training in the “Principles and Practice of Cancer Prevention and Control; and Molecular Prevention” and thereafter went to work with his collaborator in Chicago on the paraffin blocks of breast cancer cases from Ilorin for molecular studies.
He is a member of the Breast Pathology Working Group, Nigeria a team that was assembled to describe and explain proper handling of breast tissue specimens to ensure accuracy of results and subsequent treatment decisions. The ultimate goal is to improve patient outcome by optimizing personalized/individualized treatment on the basis of tumour characteristics. 
Doctor Adeniji is the founder and coordinator of Ilorin Cancer Research Group (ICRG), a multidisciplinary academic and research group, that is involved in collaborative researches with other research groups within and outside Nigeria. Our group is a member of the Sub-Saharan African Lymphoma Consortium (SSALC). Under the supervision of the Institute of Human Virology, Nigeria (IHVN), Abuja the SSALC is involved in multidisciplinary and multicenter research collaboration with Professor Leona W. Ayers of the Ohio State University. Title of research is: Modern Management of Lymphoma in HIV.
He has enjoyed many fellowships and sponsorship to various trainings, workshops and seminars. Such fellowships were from the Union for International Cancer Control (UICC), National Cancer Institute and Global Health Initiative. In October 2010 he got the American Society of Clinical Oncology-National Cancer Institute-European Organization for Research and Treatment of Cancer (ASCO-NCI-EORTC) grant and participated in the Diagnostic Development Tutorial and Molecular Markers in Cancer conference in Westin Diplomat resort in Hollywood, Florida. 
He is member of a number of local and international academic and professional organizations. Some of them include:
 American Society of Clinical Oncology (ASCO),
American Association for Cancer Research (AACR, Subgroup – Molecular Epidemiology Working Group, MEG),
European Association for Cancer Research (EACR),
European Society for Medical Oncology (ESMO), 
Association of UICC Fellows (AUF; i.e. Fellows of the Union for International Cancer Control),
African Organization for Research and Training in Cancer (AORTIC),
Association of Pathologists of Nigeria (ASSOPON) among others.
He has attended many local and international seminars, workshops and conferences wherein he presented papers and gave talks.  


Some of his publications are:


  1. Adeniji K.A., Adelusola K.A., Odesanmi W.O. (1997), "Benign diseases of the breast in Ile-Ife, a 10-year experience and literature review. Central Afr. J. Med. 43(5): 140 - 143
  2. Adeniji K.A., Adelusola K.A., Odesanmi W.O., Fadiran O.A (1997), "Histopathological analysis of carcinoma of the male breast in Ile-Ife", Nigeria, East Afr. Med. 74 (7) 555 – 557.
  3. Anjorin A.S., Adeniji K.A., Ogunsulire I.A.  (1998), "Histopathological study of prostatic lesions in Ilorin, Nigeria", Central Afr. J. Med. 44 (3): 72 – 75.
  4. Adeniji K.A., Durosinmi M.A., Odesanmi W.O. (1998), "Lymphomas of the breast in a population of Nigerian women". Nig. Postgrad. Med. J.; 5(2): 82 – 85.(Published erratum appears in Nig. Postgrad. Med. J. 1998; 5(3).
  5. Adeniji K.A., Oyegade A.U.: (1998), "Sudden death in an adult Nigerian with polycystic kidneys and subarachnoid Haemorrhage". A case report. Ilorin Doc. Med. J. 3(1): 13–15.
  6. Adeniji K.A., Anjorin A.S., Ogunsulire I.A. (1998), "Histological pattern of thyroid diseases in a Nigerian population". Nig. Qt. J. Hosp. Med.; 8(4): 241 – 244.
  7. Adeniji K.A., Anjorin A.S. (1999), "Diseases of the male breast in Ilorin, Nigeria", Nig. Qt. J. Hosp. Med.; 9(1): 8 – 10.
  8. Adeniji K.A. (1999), "Pathological Appraisal of Carcinoma of the Female Breast in Ilorin, Nigeria. Nig. Postgrad. Med. J. 6(2): 56 – 59.
  9. Adeniji K.A., Anjorin A.S. (2000), "Peripheral Lymphadenopathy in Nigeria Afr. J. Med. Med. Sci. 29: 233 – 237.
  10. Adeniji K.A. (2001), "Analysis of the histopathological pattern of carcinoma of the cervix in Ilorin, Nigeria.  Nigerian Journal of Medicine 10(4): 165 –168.
  11. Adeniji K.A. (2001), "Morphological features and organ distribution of schistosomal infection Afr. J. Med. Med. Sci. 30:53 – 56.
  12. Adeniji K.A., Anjorin A.S. (2001), "Inflammatory liver diseases in a tertiary health institution in Nigeria. Afr. J. Clin. Exp. Microbiol. 2(2): 16 – 19.
  13. Adelusola K.A., Adeniji K.A., Somotun G.O. (2001), "Lymphomas in adult Nigerians. W.A.J.M. 20(2): 123 – 126.
  14. Adeniji K.A., Anjorin A.S. (2002), "Histopathological assessment of the pattern of liver cirrhosis in a tropical population." Afr. J. Med. Med. Sci. 31:367 – 369.
  15. Adedoyin O.T., Owoeye J.F.A, Ojuawo I.A., Adeniji K.A. (2002), "Burkitt’s lymphoma affecting the orbit, occiput and kidney" A case report.  Trop. J. Health Sci. 9:25 – 27.
  16. Ologe F.E., Adeniji K.A. (2003),"Clinicopathological study of nasal nasal masses in Ilorin, Nigeria", Nig. J. Surg. 9(1): 14 – 18.
  17. Adeniji K.A. (2003), "Histopathological and histochemical patterns of soft tissue sarcomas in Ilorin, Nigeria". Afr. J. Med. Med. Sci. 32:269 – 273.
  18. Adeniji K.A., Anjorin A.S. (2004), "The pattern of malignant tumours of the liver in a tertiary health institution in Nigeria." Afr. J. Med. Med. Sci. 33:27 – 30.
  19. Adedoyin O.T., Johnson A.B.R., Ojuawo A.I. Afolayan E.A.O., Adeniji K.A. (2004) Malignant melanoma in a black child: predisposing precursors and management. J. Natl. Med. Assoc. 96(10): 1368 – 1373.
  20. Ologe F.E., Adeniji K.A., Segun-Busari S. (2005) Clinicapathological study of head and neck cancers in Ilorin, Nigeria. Tropical Doctor. 35:2-4
  21. Adedoyin O.T., Adeniji K.A. (2007) Fatal out come in a Child with Apparent Minimal Change  Nephrotic Syndrome. Nig. Postgrad. Med. J. 
  22. Dunmade, A.D., Adeniji K.A., Segun-Busari S., Eletta A.P. (2007) Nasal haemangropericytoma: A case report and literature review.  Tropical Journal of Health Sciences 14 (2): 56 – 58.