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Year : 2021  |  Volume : 24  |  Issue : 4  |  Page : 185-187

The rodent ulcer: Report of two cases

Dermatology Unit, Department of Medicine, Barau Dikko Teaching Hospital, Kaduna State University, Kaduna, Nigeria

Date of Submission22-Aug-2018
Date of Decision05-Feb-2019
Date of Acceptance22-Mar-2019
Date of Web Publication11-Feb-2022

Correspondence Address:
Dr. Husain Yahya
Dermatology Unit, Department of Medicine, Barau Dikko Teaching Hospital, Kaduna State University, Kaduna
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/smj.smj_47_18

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A rodent ulcer refers to the slowly growing, ulcerated, locally invasive basal-cell carcinoma (BCC) which is the most common cutaneous malignancy in Caucasians but is rare in people with dark skin. We report two morphologically different presentations of nodular BCC in Nigerian patients. The first was a large, slowly growing ulcer on the right side of the face which had been present for many years, with the diagnosis not being made despite visits to various health centers, whereas the second was a much smaller ulcerated nodule on the right alar nasi and dorsum of the nose. We highlight the need for vigilance to make the correct diagnosis early and institute appropriate treatment.

Keywords: Basal-cell carcinoma, clinical presentations, dark-skinned patients, rodent ulcer

How to cite this article:
Yahya H. The rodent ulcer: Report of two cases. Sahel Med J 2021;24:185-7

How to cite this URL:
Yahya H. The rodent ulcer: Report of two cases. Sahel Med J [serial online] 2021 [cited 2023 May 31];24:185-7. Available from: https://www.smjonline.org/text.asp?2021/24/4/185/337488

  Introduction Top

A rodent ulcer refers to the slowly growing, locally invasive basal-cell carcinoma (BCC) which is the most common skin cancer in Caucasians.[1] Up to 30% of Caucasians develop BCC during their lifetime depending on the level of sun exposure – Caucasians living in Australia have the highest rates of skin cancer in the world with a rate as high as 1193/100,000 in Townsville, North Queensland, Australia.[2] BCC is rare in darkly pigmented people; the incidence of BCC in dark-skinned people in Kenya was estimated to be <1/10,000 persons/year in a report.[3] Because of its slow growth and infrequent distant metastases, patients with BCC may present late with large ulcers even in areas in which the disease is well-known, especially in the elderly living alone.[4] Furthermore perhaps, because of the lack of familiarity with the condition in countries in which it is rare, health-care providers may not refer patients early leading to a delay in the diagnosis. We report two cases of nodular pigmented BCC: one presenting late as a true “rodent ulcer” and another case presenting much earlier, and therefore, amenable to less drastic treatment such as a simple excision with adequate margins. We also briefly review the literature on BCC in dark-skinned patients.

  Case Reports Top

Case report 1

A 56-year-old Nigerian woman, from a rural area, presented to the skin clinic with a 4-year history of a lesion on the right side of the face which started as a small lesion but which later became ulcerated and increased in size slowly. The patient had sought treatment in various health centers over the years, but the lesion had refused to heal. On examination, there was a large 5 cm × 5 cm triangular plaque on the right side of the face extending from the lower eye lid, superiorly, with ectropion formation, to dorsum of the nose covering almost its right lateral half and part of the alar nasi medially, to just above the angle of the mouth inferiorly and extending to the zygomatic arch superior-laterally [Figure 1]. The lesion had a well-defined, irregular, hyperpigmented, and in some places, ulcerated edge which had a firm nodule on its inferior pole. There were also irregular areas of hyperpigmentation throughout the inside of the plaque as well multiple scattered areas of ulceration and scab formation. The majority of the lesion appeared flat and atrophied. Histology of a 4-mm punch biopsy taken from the inferior papulonodular edge of the lesion showed nodular collection of malignant basaloid cells infiltrating into the reticular dermis [Figure 2]. There were pockets of melanin deposits in the superficial dermis. The patient was referred for surgery.
Figure 1: Clinical photograph of a large slowly growing nodular basal-cell carcinoma

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Figure 2: Photomicrograph of nodular basal-cell carcinoma showing collections of basaloid malignant cells infiltrating into the reticular dermis (H and E, ×100)

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Case report 2

A 65-year-old Nigerian woman presented to the skin clinic with a 1-year history of an asymptomatic lesion on the right alar nasi which had refused to heal despite treatment. The lesion had started small and increased in size gradually and had become ulcerated in the center. On examination, there was a 1.5 cm, round, darkly pigmented firm dome-shaped nodule with central dry ulceration and covering part of the right alar nasi and extending to involve part of the dorsum of the nose [Figure 3]. Histology of a 3-mm punch biopsy showed features consistent with nodular BCC.
Figure 3: Clinical photograph of a nodular basal-cell carcinoma lesion with a central dry ulcer

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  Discussion Top

The cases illustrate two different classic presentations of nodular BCC, the most common type of BCC. The first case has most likely been present for longer than the history suggests. It is a frequent observation that African patients with malignant disease present late to the hospital and often give a shorter history for fear of reprimand.[5] Over the course of many years, the patient had also been treated at various health centers in her area, but the lesion had refused to heal. A lack of familiarity with BCC in the primary healthcare may have contributed to delay in the diagnosis and treatment in this patient. To emphasize its rarity, the author has seen only three cases of BCC in 19 years of dermatology practice. Most reports of BCC from Nigeria have been surgical or histopathological reports[6],[7] and that have involved a large number of albinos who are well-known to have a high risk of development of BCC as well as the more common squamous cell carcinoma. These patients usually develop multiple tumors and present late thus complicating care.[8] The lesson here is that clinicians should have a high index of suspicion for referral and biopsy in any patient, especially a middle-aged or elderly patient who presents with a nonhealing lesion or ulcer on the face or neck regions.

The second case, on the other hand, presented much earlier and would be far more amenable to excision than the first case.

It is still an enigma why darkly pigmented African patients develop BCC. This malignancy is the most common skin cancer in the lightly pigmented Caucasian races of Northern Europe, North America, Australia, and South Africa.[1] The incidence of BCC is higher the closer these races live to the equator or higher the altitude.[1] It is obvious that there may be other factors at play in the rare cases of BCC that are seen in dark-skinned patients who are protected by the heavy melanin content and melanosome dispersion of their skin.[9] Although majority of the cases occurring in these patients occur in the same head-and-neck region, a relatively larger number of cases occur in nonsun exposed regions of the trunk and lower extremities than in Caucasians.[9] The causes other than sun exposure such as chronic arsenic ingestion, exposure to ionizing radiation, long-standing immunosuppression, xeroderma pigmentosum, or the very rare Gorlin's syndrome have been associated with BCC,[1] but these appear not to be the case in our patients. Perhaps, this cancer in dark-skinned patients represent gene mutations in genes such as the patched homolog 1 gene (PTCH1), bcl-2 associated X protein (BAX gene), or p53 which have been implicated in sporadic cases of BCC.[10]

  Conclusion Top

We have reported two rare cases of BCC in two Nigerian patients in which one presented late with a large ulcerated lesion on the face which will require very wide excision and reconstructive surgery, and another who presented early and is amenable to simple excision. We highlight the need for vigilance in order make the correct diagnosis early and institute the appropriate treatment.

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Conflicts of interest

There are no conflicts of interest.

  References Top

Verkouteren JA, Ramdas KH, Wakkee M, Nijsten T. Epidemiology of basal cell carcinoma: Scholarly review. Br J Dermatol 2017;177:359-72.  Back to cited text no. 1
Raasch BA, Buettner PG. Multiple nonmelanoma skin cancer in an exposed Australian population. Int J Dermatol 2002;41:652-8.  Back to cited text no. 2
Munyao TM, Othieno-Abinya NA. Cutaneous basal cell carcinoma in Kenya. East Afr Med J 1999;76:97-100.  Back to cited text no. 3
MacKie RM, Queen AG. Non-melanoma skin cancer and other epidermal tumours. In: Burns T, Breathnach S, Cox N, Griffiths C, editors. Rook's Textbook of Dermatology. 7th ed. Oxford: Blackwell Science; 2004. p. 36.20.  Back to cited text no. 4
Akuoko CP, Armah E, Sarpong T, Quansah DY, Amankwaa I, Boateng D, et al. Barriers to early presentation and diagnosis of breast cancer among African women living in Sub-Saharan Africa. PLoS One 2017;12:e0171024.  Back to cited text no. 5
Asuquo ME, Otei O, Nwagbara V, Ebughe G, Omotoso J. Basal cell carcinoma: Experience in a teaching hospital, Calabar, South Nigeria. Int J Clin Med 2011;2:93-6.  Back to cited text no. 6
Ochicha O, Edino ST, Mohammed AZ, Umar AB. Dermatological malignancies in Kano, Northern Nigeria: A histopathological review. Ann Afr Med 2004;3:188-91.  Back to cited text no. 7
Opara KO, Jiburum BC. Skin cancers in albinos in a teaching hospital in Eastern Nigeria – Presentation and challenges of care. World J Surg Oncol 2010;8:73.  Back to cited text no. 8
Mora RG, Burris R. Cancer of the skin in blacks: A review of 128 patients with basal-cell carcinoma. Cancer 1981;47:1436-8.  Back to cited text no. 9
Patterson JW. Tumours of the epidermis. In: Weedon's Skin Pathology. 4th ed. London: Churchill Livingstone; 2016. p. 785-835.  Back to cited text no. 10


  [Figure 1], [Figure 2], [Figure 3]


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