An Unusual Case of Metastasis to Bilateral Breasts Masquerading as Disseminated Tuberculosis in a 17-Year-Old Girl with Quadriplegia-Where Is the Primary? An Unsolved Mystery.

Invasive breast cancer, no special type, is the most frequent subtype of breast malignancy encountered as compared to secondary breast cancer. The most common tumors metastasizing to the breast include lymphoma and melanoma. Rhabdomyosarcoma (RMS) is a common soft-tissue neoplasm in the paediatric population, often seen in regions such as the head and neck, genitourinary system, trunk, and extremities. While metastatic RMS to the breast is uncommon, it tends to occur primarily in adolescent girls, with the alveolar variant being the most frequently encountered. In this case presentation, we describe the unique instance of a 17-year-old girl admitted to the hospital with quadriplegia which on initial clinical evaluation was diagnosed as disseminated tuberculosis involving the spine (Pott's spine), but on further cytologic and histopathologic assessment revealed the unexpected diagnosis of rhabdomyosarcoma. This case draws attention to the unusual occurrence of rhabdomyosarcoma metastasis to bilateral breasts, that to with an embryonal morphology, and underscores the challenge of identifying the primary site of this rare manifestation.