Digital Pathology in Cameroon

Abstract

Purpose: Cancer is becoming increasingly prevalent among the group of treatable diseases in African countries. There is a shortage of clinicians and pathologists available for cancer diagnosis and treatment. These limited resources must be efficiently used to maximize the number of patients treated. One of the critical factors in treatment efficiency is the correct and timely diagnosis of specimens by pathologists. However, there is currently a significant shortage of cancer care clinicians in Africa and an even more considerable shortage of pathologists. This article presents an example in which telepathology was used to mitigate the lack of pathologists in Cameroon.

Methods: The telepathology workaround was implemented in a district hospital based in Cameroon's Adamawa region, where a European surgeon provides cancer treatment. A small histology laboratory there is run by one histotechnologist who processes surgical biopsies into histology slides. As there are no pathologists on site, these slides are digitally scanned using a mobile phone and a whole slide imaging (WSI) scanner. The slides are then shared electronically with a volunteering pathologist in Europe who provides a diagnostic report.

Results: From 2018 to July 2019, specimens for 101 patients were photographed through an iPhone connected to a microscope eyepiece producing several individual images per specimen. From July 2019 to December 2020, slides from 282 patients were scanned using WSI and digitally transmitted.

Conclusion: WSI on hematoxylin and eosin histology slides for remote diagnosis can increase cancer treatment efficacy and reduce overtreatment of tumors clinically suspicious for malignancy in under-resourced countries with a lack of pathologists.

FIG 1

There was a short period of instruction by a pathologist staying in the hospital in Ngaoubela for 3 weeks. This pathologist left detailed written instruction for continued excision and imaging after the stay. The technician was also taught to capture slide images through the microscope eyepiece using an iPhone.

FIG 2

Diagnosis of WSI scans: The pathologist receives a picture of the written request paperwork and a gross image of the glass slides, and can access the WSI via Telegram utilizing free-to-use viewers for diagnosis, including ImageScope and qPath.

FIG 3

Step 1: The workflow begins with the surgeon in Cameroon excising the specimen and sending the tissue for processing. Step 2: The technician processes the specimen in Cameroon to create H&E slides. Step 3: The slides are digitized by photographing through the microscope eyepiece (phase I) or via slide scanner (phase II). Step 4: The images are uploaded to cloud storage. Step 5: The pathologist in Austria reviews the images and generates the pathology reports. Step 6: The reports are uploaded to cloud storage and sent via instant messaging to the surgeon in Cameroon. H&E, hematoxylin and eosin.

FIG 4

Diagnostic certainty of single image versus whole slide imaging cases: 101 camera image cases and 273 whole slide imaging cases. Some cases lacked a recorded category and are excluded. Diagnostic: exact diagnosis—therapy can be based on diagnosis. Differential only: differential diagnoses—therapy is influenced by diagnosis in context with further clinical analyses. Nondiagnosable: no diagnosis possible—no therapy guidance. %: percent of cases in certainty groups 1-3, N: absolute number of cases in certainty groups 1-3. iPhone, single images by using iPhone camera; WSI, whole slide imaging.

FIG 5

Box and whisker chart comparing the distributions of the length of each interval between recorded dates describing case progression as listed in Table 3: (A) iPhone data (cases 129-229) and (B) WSI data (cases 412-531). iPhone, single images by using iPhone camera; WSI, whole slide imaging.

FIG 6

Stacked area graph by case for (A) iPhone data (cases 129-229) and (B) WSI data (cases 412-531), where the total summed height at each point represents the total number of days from procedure to final pathology report. Each color represents the individual contribution to total time from each interval between recorded dates of case progression, as defined in Table 1. iPhone, single images by using iPhone camera; WSI, whole slide imaging.

FIG A1

Distribution of the biopsied organs. The total number of specimens is 383; 101 iPhone (camera) cases and 282 WSI cases. Absolute numbers were used. Eight recorded cases did not have a tissue of origin recorded and are omitted here. Derm = skin; GI = gastrointestinal; Gyn = uterus including cervix, ovary, and gestational pathology; Hep = liver; Lymph = lymph nodes; Oral = head and neck; Uro = kidney, urinary tract, and prostate; breast includes male and female; soft tissue includes bone. WSI, whole slide imaging.