Metaplastic breast carcinoma with predominant squamous differentiation in rural Tanzania: a case report highlighting diagnostic and treatment access barriers
Bahati G. Kamwezi, Edrick Elias, Nelice S. Deogratius, Tresphory Boniphace Kamushaga, Agnes L. Mlawa, Mirko LombardiIntroduction and importance:
Metaplastic breast carcinoma (MBC) is an uncommon and biologically aggressive breast malignancy whose diagnosis and treatment depend on accurate histopathology, receptor characterization, complete staging, and access to multidisciplinary oncology. In resource-constrained settings, delays may arise not only from the absence of services but also from the inability to access services that are technically available.
Case presentation:
A 38-year-old Tanzanian woman presented with a rapidly enlarging recurrent left breast mass 10 months after local excision of the original lesion without histopathological examination. She had enlarged but mobile ipsilateral axillary nodes on palpation. Tru-Cut biopsy confirmed a malignant breast neoplasm. Chest radiography and abdominal ultrasonography showed no secondary lesions; computed tomography was recommended but was not obtained because the patient reported that she could not afford it, and immunohistochemistry was unavailable locally. After initially declining referral and requesting local treatment, she underwent modified radical mastectomy with level I–II axillary dissection and selective level III nodal removal. Histology showed a 13 × 7 × 5 cm high-grade MBC with predominantly poorly differentiated squamous differentiation, extensive lymphovascular invasion, focal rhabdoid-appearing cells within tumor emboli, and metastases in four of nineteen axillary nodes (pT3 pN2a).
Clinical discussion:
The differential diagnosis included malignant phyllodes tumor, primary breast sarcoma, and pure squamous cell carcinoma of the breast. Morphology favored MBC, although the lack of local immunohistochemistry limited receptor classification and ancillary confirmation. Following postoperative counseling, the patient independently mobilized financial resources and attended the Ocean Road Cancer Institute (ORCI) in Dar es Salaam. Hormone-receptor testing was performed there, although the results were not available to the authors. According to the patient, PET imaging performed at ORCI showed no distant metastases. A four-cycle chemotherapy course was commenced; at 4 months after surgery, she had completed two cycles at approximately 4-week intervals, was clinically free of evident recurrence, and had resumed normal daily activities. Radiotherapy was to be discussed after chemotherapy.
Conclusion:
The importance of this case extends beyond tumor rarity. It demonstrates the interaction between aggressive MBC, diagnostic delay after excision without histopathology, incomplete local staging and limited biomarker access, and eventual specialist oncology referral after financial resources were secured. Routine pathology for all excised breast lesions, affordable staging and receptor testing, reliable referral pathways, and financial protection for cancer care are actionable priorities for rural sub-Saharan African health systems.