Scleromyxedema and lichen myxedematosus (LM) are rare disorders that fall along the spectrum of primary cutaneous mucinoses. Scleromyxedema is a systemic form that classically presents with generalized waxy papules, sclerodermoid eruption, and monoclonal gammopathy; LM is a localized form limited to the skin that classically presents with white, firm, waxy papules and lacks monoclonal gammopathy. According to diagnostic criteria established in 2001, the diagnosis of both conditions requires absence of thyroid disease. However, atypical cases that lack monoclonal gammopathy and that present with hypothyroidism have been reported, suggesting that these criteria may require revision. First, we report a case of a 58-year-old female with a history of Hashimoto thyroiditis and biopsy-proven scleromyxedema responsive to intravenous immunoglobulin therapy with delayed presentation of monoclonal gammopathy. Next, we report a case of a 54-year-old female with a history of hypothyroidism, Hodgkin's lymphoma in remission after radiation and chemotherapy, and concurrent rheumatoid arthritis, with biopsy-proven LM temporarily responsive to systemic steroids. Our cases demonstrate that patients with papular mucinoses can have a multitude of concurrent and prior rheumatologic and endocrine conditions, including thyroid disease, which should not preclude a diagnosis of scleromyxedema and LM.