What is the most likely diagnosis for Jacob, whose "lump on his back" over the scapula has been growing and can yield a cheesy-textured substance?

The diagnosis of a sebaceous cyst is supported by Jacob's description of a lump on his back over the scapula that has been growing and can yield a cheesy-textured substance. Sebaceous cysts, also known as epidermoid cysts, are common benign lumps that form when the sebaceous gland or hair follicle becomes blocked. The contents of these cysts often consist of keratin and can have a cheesy or pasty texture, which matches the description of the substance that can be expressed from the cyst.

In contrast, the other conditions mentioned have different characteristics and presentations. Squamous cell carcinoma typically presents as a new growth or sore on the skin that does not heal rather than a lump with expressive cheesy content. A pilonidal cyst usually occurs near the tailbone, not on the back over the scapula, and is often associated with hair and can become infected but does not generally yield cheesy material. Soft tissue sarcomas are malignant tumors that would not present as a cheesy-textured lump; they tend to be firm and may be painful, along with other alarming systemic symptoms, rather than having the classic presentation of a sebaceous cyst.