Squamous Cell Carcinoma Tops Skin Cancer Diagnoses in Five-Year Kabul Study

Squamous cell carcinoma, not basal cell carcinoma, was the most common malignant skin tumor diagnosed at a tertiary care center in Kabul, Afghanistan, according to a five-year review of 436 histopathologically confirmed cases published in Discover Medicine.

The case mix diverged sharply from international patterns. Squamous cell carcinoma accounted for 229 cases, or 52.5 percent of the total, followed by basal cell carcinoma with 156 cases (35.7 percent), malignant melanoma with 22 cases (5.0 percent), sebaceous carcinoma with 20 cases (4.5 percent), and sarcomas including dermatofibrosarcoma and angiosarcoma with 9 cases (2.0 percent). Classified according to the World Health Organization taxonomy of skin tumors, keratinocytic tumors dominated, making up 385 cases, or 88.3 percent of all malignant cutaneous neoplasms in the series. Among squamous cell carcinomas, the most frequently diagnosed subtype was squamous cell carcinoma not otherwise specified, followed by keratoacanthoma and verrucous carcinoma, while among basal cell carcinomas the common morphologic subtype was basal cell carcinoma not otherwise specified, followed by basosquamous, pigmented, superficial, nodular, sclerosing, and infiltrating forms.

The authors suggest the prominence of squamous cell carcinoma may reflect the skin pigmentation of the local population, described in the study as generally Type II fair or beige skin, along with inherited genetic variability and sociocultural differences, noting that basal cell carcinoma typically arises in lighter skin that is vulnerable to ultraviolet exposure. They caution that further large-scale analytic studies are needed to reveal the possible linked factors. Globally, skin cancers remain the most common group of cancers diagnosed, with more than 1.5 million new cases estimated in 2022, including approximately 330,000 new melanoma cases and nearly 60,000 melanoma deaths that year.

Men carried the majority of the disease burden. Of the 436 patients, 294 (67.4 percent) were male and 142 (32.6 percent) were female, a male-to-female ratio of 2.07. The mean age at diagnosis was 62.2 years and the median was 65.0 years, with a standard deviation of 17.5 years. Age patterns differed by sex: malignant skin tumors were most common in men aged 61 to 80 years, who accounted for 141 of 294 male cases (47.9 percent), whereas in women they were most frequent at ages 51 to 70, comprising 70 of 142 female cases (49.3 percent). The researchers link these sex-specific age patterns to differences in cumulative sun exposure shaped by social and cultural factors, noting that Afghan men are more likely to work outdoors in occupations such as farming and construction, while women often wear clothing that covers most of the body, and that women may also seek treatment for skin lesions at earlier ages.

Anatomically, the disease clustered where the sun hits hardest. The head and neck was the most affected body region, accounting for 292 cases (66.9 percent), followed by the extremities with 89 cases (20.4 percent), the trunk with 19 cases (4.3 percent), and the genitoperineal region with 13 cases (2.9 percent). When sites were grouped by sun exposure, severely exposed areas such as the face, neck, ears, and the dorsal surfaces of the hands and forearms accounted for 195 male cases (66 percent) and 96 female cases (68 percent), with intermediately exposed and covered sites trailing in both sexes. Within the head and neck, the nose was the single most common site in both sexes, involved in 44 male cases (22.5 percent) and 30 female cases (30.9 percent). In men the orbital region ranked second, followed by cheek, ear, lip, scalp, and neck; in women the cheek ranked second, followed by the orbital region, scalp, lip, ear, and neck. The study found a statistically significant association between sex and tumor site (p = 0.038), and the authors observe that skin cancers of the ear were not more common in females than in males, a pattern they plausibly attribute to clothing practices such as shawls or veils.

Tumor grade carried prognostic weight in the squamous cell carcinoma subset, the only tumor type for which the WHO grading system applies. Grade I tumors were the most frequent at diagnosis, accounting for 169 cases, or 73.7 percent of the 229 squamous cell carcinomas, followed by Grade II tumors with 56 cases (24.4 percent) and Grade III tumors with 11 cases (4.8 percent of SCC cases). Metastatic behavior rose steeply with grade: no metastasis was identified in Grade I tumors, while the metastatic rate increased to 5.3 percent (3 cases) in Grade II tumors and 54.4 percent (6 of 11 cases) in Grade III tumors. The authors note this grade-metastasis relationship is supported by multiple other studies, although some literature reports no significant relationship between tumor differentiation and metastatic rate.

Two operational findings stood out as sharply as the tumor counts. First, the clinical information supplied by physicians on histopathology request forms was strikingly sparse. Using a four-point scoring system developed by the research team and adapted from prior literature, the team found that the largest share of forms, 203 cases (46.5 percent), fell into the lowest completeness category, mentioning only age and sex or tumor site. Another 131 forms (30.3 percent) reached the second category, 63 (14.4 percent) the third, and only 29 forms (6.6 percent) contained the full set of age, sex, tumor site, duration, and appearance or clinical impression. The authors warn that incomplete clinical history can affect the final diagnosis, treatment outcomes through sub- or overdiagnosis, and reporting time, and they call for strategic approaches beginning at the level of the Ministry of Health to engage all healthcare institutions in Afghanistan.

Second, many tumors coded clinically as complete excisional biopsies were not, in fact, completely removed. Excisional biopsy was the most common procedure, performed in 190 patients (43.6 percent), followed by punch biopsy in 166 patients (38.1 percent) and incisional biopsy in 80 patients (18.3 percent), a distribution that contrasts with international practice, where punch biopsy is the most common procedure. Among the 190 clinically coded excisional biopsies, the tumor margin was microscopically involved in 115 patients (60.5 percent), and complete excision was confirmed in only 75 patients (39 percent). Most excised tumors measured between 1.5 and 4 centimeters, accounting for 136 of the 190 specimens (71.5 percent), with 54 cases (28.4 percent) at 4 centimeters or larger. Most tumors were excised or treated only after a duration of one to four years, constituting 16.3 percent of cases, while 48 cases (11 percent) were treated within less than one year, a delay the authors connect to the lack of specialized institutions in Afghanistan.

The study has limitations the authors spell out explicitly. It was conducted at a single center which, although it receives cases from across Afghanistan, may not fully represent the country’s diverse population. The retrospective design relied on existing records that often lacked comprehensive clinical data, potentially introducing bias or underrepresenting certain patient demographics and tumor characteristics. The sample size may restrict generalizability, particularly for rare skin cancer subtypes, and environmental exposures and genetic predispositions were not thoroughly examined. The authors call for future multicenter, prospective studies with larger and more diverse samples, and they argue that raising awareness among the public and among clinicians dealing with lesions suspected of malignancy is a key step that should be taken by the Ministry of Public Health and other health authorities to improve the management of malignant skin disorders in the country.

Subject of Research: The frequency and histopathological features of malignant skin tumors diagnosed at a tertiary care center in Kabul, Afghanistan

Article Title: Proportion and histopathological features of cutaneous malignant tumors diagnosed in a tertiary care center in Kabul, Afghanistan

Article References: Haidari, M., Malakzai, H. A., Haidary, A. M., Hofiani, S. M. S., Parpio, Y. N., Saadaat, R., Esmat, E., Khairy, A. L., Hakimi, A., Baset, Z., Fakhri, M. Y., & Abdul-Ghafar, J. (2026). Proportion and histopathological features of cutaneous malignant tumors diagnosed in a tertiary care center in Kabul, Afghanistan. Discover Medicine, 3(1), Article 153. https://doi.org/10.1007/s44337-026-00725-2

Image Credits: AI Generated

DOI: 10.1007/s44337-026-00725-2

Keywords: skin cancer, squamous cell carcinoma, basal cell carcinoma, melanoma, Afghanistan, histopathology, Kabul, retrospective study, resection margins, ultraviolet exposure, Proportion, histopathological